JP2020520049A - Formulation of organic functional materials - Google Patents

Abstract

The present invention is a formulation containing at least one organic functional material and at least a first organic solvent, wherein the first organic solvent contains at least one formic acid group, and It relates to electronic devices prepared by using these formulations.

Description

The present invention relates to a formulation containing at least one organic functional material and at least a first organic solvent, the first organic solvent containing at least one formic acid group, Furthermore, it relates to electronic devices, preferably electroluminescent devices, prepared by using these formulations.
Background Art Organic light emitting devices (OLEDs) have long been made by vacuum deposition processes. Other techniques, such as inkjet printing, have recently been thoroughly researched for their advantages, such as cost savings and potential for scale-up. One of the main challenges in multi-layer printing is identifying the relevant parameters to obtain uniform ink deposition on the substrate. Several additives can be added to the formulation to induce such parameters, such as surface tension, viscosity, or boiling point.
SUMMARY OF THE INVENTION Many solvents have been proposed in organic electronic devices for inkjet printing. However, the number of important parameters that play a role during the deposition and drying process make solvent selection very difficult. Therefore, formulations containing organic semiconductors used for inkjet printing deposition are still in need of improvement. One object of the present invention is to provide a formulation of organic semiconductors that allows controlled deposition to form organic semiconductor layers with good layer properties and efficiency performance. A further object of the invention is the preparation of organic semiconductors which, for example, when used in ink jet printing processes, makes it possible to apply ink droplets uniformly on a substrate, which leads to good layer properties and efficiency performance. Is to provide.
Solution to Problem The above-mentioned object of the present invention is to provide at least one organic functional material and at least a first organic solvent, wherein the first organic solvent contains at least one formic acid group, preferably one formic acid group. The solution is to provide a formulation comprising an organic solvent.
EFFECTS OF THE INVENTION The inventors have surprisingly found that the use of an organic solvent containing at least one formic acid group as the first solvent allows complete control of the surface tension and induces effective ink deposition. Have been found to form organic layers of uniform and well-defined functional materials with good layer properties and performance.
Description of the Embodiments The present invention is a formulation containing at least one organic functional material and at least a first organic solvent, wherein the first organic solvent is at least one formic acid group, preferably one. It relates to a formulation containing a formic acid group.
Preferred Embodiment In the first preferred embodiment, the first organic solvent containing one formic acid group has the general formula (I)

(In the formula,
R is
-H, F,
-A linear alkyl group having 1 to 20 carbon atoms, a linear alkenyl group having 2 to 20 carbon atoms, or a branched alkyl or alkenyl group having 3 to 20 carbon atoms (wherein 1 One or more non-adjacent CH ₂ groups are —O—, —S—, —NR ¹ —, —CONR ¹ —, —CO—O—, —C═O—, —CH═CH— or —C. ≡ C-, optionally one or more hydrogen atoms may be replaced by F), or-optionally substituted by one or more non-aromatic R ¹ radicals, 6 A cyclic alkyl or alkenyl group having 20 to 20 carbon atoms or an aryl or heteroaryl group having 4 to 14 carbon atoms, wherein the plurality of substituents R ¹ are either on the same ring or on two different rings. And may together form a monocyclic or polycyclic aliphatic or aromatic ring system optionally substituted by a plurality of substituents R ¹ .
R ¹ is the same or different in each case and is a straight-chain alkyl or alkoxy group having 1 to 20 carbon atoms or a branched or cyclic alkyl or alkoxy group having 3 to 20 carbon atoms (here And one or more non-adjacent CH ₂ groups are replaced by —O—, —S—, —CO—O—, —C═O—, —CH═CH— or —C≡C—. Optionally one or more hydrogen atoms may be replaced by F), or having from 4 to 14 carbon atoms and optionally substituted by one or more non-aromatic R ¹ radicals. A good aryl or heteroaryl group;
X is a linear alkyl group having 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms, 2 to 10 linear chain alkenyl groups having 2 to 5 carbon atoms, or 3 to 10 carbon atoms; Preferred is a branched alkyl or alkenyl group having 3 to 5 carbon atoms;
n is 0 or 1)
Is a solvent containing a formic acid group according to.

In a first more preferred embodiment, the first organic solvent containing one formic acid group is of the general formula (I)
(In the formula,
R is an aryl or heteroaryl group having 4 to 14 carbon atoms, which may be substituted by one or more non-aromatic R ¹ radicals, the plurality of substituents R ¹ are on the same ring or Either on two different rings may together form a mono- or polycyclic aliphatic or aromatic ring system optionally substituted by a plurality of substituents R ¹ .
R ¹ is the same or different in each case and is a straight-chain alkyl or alkoxy group having 1 to 20 carbon atoms or a branched or cyclic alkyl or alkoxy group having 3 to 20 carbon atoms (here And one or more non-adjacent CH ₂ groups are replaced by —O—, —S—, —CO—O—, —C═O—, —CH═CH— or —C≡C—. Optionally one or more hydrogen atoms may be replaced by F), or having from 4 to 14 carbon atoms and optionally substituted by one or more non-aromatic R ¹ radicals. A good aryl or heteroaryl group;
X is a linear alkyl group having 1 to 5 carbon atoms, a linear alkenyl group having 2 to 5 carbon atoms or a branched alkyl or alkenyl group having 3 to 5 carbon atoms;
n is 0 or 1)
Is a solvent containing a formic acid group according to.

In a first and most preferred embodiment, the first organic solvent containing one formic acid group is of the general formula (II)

(In the formula,
R ¹ is the same or different in each case and is H, a linear alkyl or alkoxy group having 1 to 20 carbon atoms, a linear alkenyl group having 2 to 20 carbon atoms, or 3 to branched or cyclic alkyl or alkoxy group having 20 carbon atoms (wherein the CH ₂ group which is not one or more adjacent, -O -, - S -, - CO-O -, - C = O -, -CH=CH- or -C[identical to]C-, one or more hydrogen atoms may be replaced by F), or has 4 to 14 carbon atoms. An aryl or heteroaryl group optionally substituted by one or more non-aromatic R ¹ radicals;
X is a linear alkyl group having 1 to 5 carbon atoms, a linear alkenyl group having 2 to 5 carbon atoms or a branched alkyl or alkenyl group having 3 to 5 carbon atoms;
n is 0 or 1,
m is 0, 1, 2, 3, 4 or 5, preferably 0, 1 or 2.
Is a solvent containing a formic acid group according to.

In a second more preferred aspect, the first organic solvent containing one formic acid group is of the general formula (I)
(In the formula,
R is a cyclic alkyl or alkenyl group having 6 to 20 carbon atoms, which may be substituted by one or more non-aromatic R ¹ radicals, and multiple substituents R ¹ are on the same ring or Either on two different rings may together form a mono- or polycyclic aliphatic or aromatic ring system optionally substituted by a plurality of substituents R ¹ .
R ¹ is the same or different in each case and is a straight-chain alkyl or alkoxy group having 1 to 20 carbon atoms or a branched or cyclic alkyl or alkoxy group having 3 to 20 carbon atoms (here And one or more non-adjacent CH ₂ groups are replaced by —O—, —S—, —CO—O—, —C═O—, —CH═CH— or —C≡C—. Optionally one or more hydrogen atoms may be replaced by F), or having from 4 to 14 carbon atoms and optionally substituted by one or more non-aromatic R ¹ radicals. A good aryl or heteroaryl group;
X is a linear alkyl group having 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms, 2 to 10 linear chain alkenyl groups having 2 to 5 carbon atoms, or 3 to 10 carbon atoms; Preferred is a branched alkyl or alkenyl group having 3 to 5 carbon atoms;
n is 0 or 1)
Is a solvent containing a formic acid group according to.

In a second most preferred embodiment, the first organic solvent containing one formic acid group is of the general formula (I)
(In the formula,
R is a cyclic hexyl or hexenyl group optionally substituted by one or more non-aromatic R ¹ radicals, a plurality of substituents R ^{1 taken} together being substituted by a plurality of substituents R ¹ . May form a mono- or polycyclic aliphatic or aromatic ring system;
R ¹ is the same or different in each case and is a straight-chain alkyl or alkoxy group having 1 to 20 carbon atoms or a branched or cyclic alkyl or alkoxy group having 3 to 20 carbon atoms (here And one or more non-adjacent CH ₂ groups are replaced by —O—, —S—, —CO—O—, —C═O—, —CH═CH— or —C≡C—. May));
X is a linear alkyl group having 1 to 5 carbon atoms, a linear alkenyl group having 2 to 5 carbon atoms or a branched alkyl or alkenyl group having 3 to 5 carbon atoms;
n is a solvent containing a formic acid group according to 0 or 1.

In a third more preferred embodiment, the first organic solvent containing one formic acid group has the general formula (III)

(In the formula,
R is a straight chain alkyl group having 1 to 20 carbon atoms, a straight chain alkenyl group having 2 to 20 carbon atoms, or a branched alkyl or alkenyl group having 3 to 20 carbon atoms (wherein The one or more non-adjacent CH ₂ groups are —O—, —S—, —NR ¹ —, —CONR ¹ —, —CO—O—, —C═O—, —CH═CH— or —C≡C—, optionally one or more hydrogen atoms may be replaced by F);
R ¹ is the same or different in each case and is a straight-chain alkyl or alkoxy group having 1 to 20 carbon atoms or a branched or cyclic alkyl or alkoxy group having 3 to 20 carbon atoms (here And one or more non-adjacent CH ₂ groups are replaced by —O—, —S—, —CO—O—, —C═O—, —CH═CH— or —C≡C—. Or one or more hydrogen atoms may be replaced by F)).
Is a solvent containing a formic acid group according to.

In a third most preferred embodiment, the first organic solvent containing one formic acid group is of the general formula (III)
(In the formula,
R is a straight chain alkyl group having 1 to 20 carbon atoms, a straight chain alkenyl group having 2 to 20 carbon atoms, or a branched alkyl or alkenyl group having 3 to 20 carbon atoms (wherein , one or more _non-adjacent CH ₂ groups to the can also be) optionally replaced by -CH = CH-)
Is a solvent containing a formic acid group according to.

Examples of preferred formic acid group containing solvents and their boiling points (BP) are shown in Table 1 below.

Preferably, the first solvent has a surface tension of 20 mN/m or higher. More preferably, the surface tension of the first solvent is in the range 25-45 mN/m, most preferably in the range 30-40 mN/m.

The content of the first solvent is preferably in the range of 50 to 100 vol%, more preferably in the range of 75 to 99 vol%, and most preferably in the range of 90 to 99 vol%, based on the total amount of the solvents in the formulation. ..

As a result, the content of the second solvent is preferably in the range of 0 to 50 vol%, more preferably in the range of 1 to 25 vol%, most preferably in the range of 1 to 10 vol%, based on the total amount of solvent in the formulation. It is a range.

Preferably, the first solvent has a boiling point in the range 100-400°C, more preferably in the range 150-350°C.

The formulation according to the invention comprises in a preferred embodiment at least a second solvent which is different from the first solvent. The second solvent is used with the first solvent.

In one aspect, the second solvent can also be a solvent containing a different formic acid group than the first solvent. However, preferably, the second solvent does not contain a formic acid group.

Suitable second solvents are preferably alcohols, aldehydes, ketones, ethers, esters, amides, such as di-C _1-2 -alkylformamides, sulfur compounds, nitro compounds, hydrocarbons, halogenated hydrocarbons (eg, Chlorinated hydrocarbons), aromatic or heteroaromatic hydrocarbons, and halogenated aromatic or heteroaromatic hydrocarbons.

Preferably, the second solvent is of the following group: substituted and unsubstituted aromatic or linear esters such as ethylbenzoate, butylbenzoate; substituted and unsubstituted aromatic or linear ethers such as 3 -Phenoxytoluene or anisole; substituted or unsubstituted arene derivatives such as xylene; indane derivatives such as hexamethylindane; substituted and unsubstituted aromatic or linear ketones; substituted and unsubstituted heterocyclic compounds such as pyrrolidinone , Pyridine, pyrazine; one of the other fluorinated or chlorinated aromatic hydrocarbons.

Particularly preferred second organic solvents are, for example, 1,2,3,4-tetramethylbenzene, 1,2,3,5-tetramethylbenzene, 1,2,3-trimethylbenzene, 1,2,4,5. -Tetramethylbenzene, 1,2,4-trichlorobenzene, 1,2,4-trimethylbenzene, 1,2-dihydronaphthalene, 1,2-dimethylnaphthalene, 1,3-benzodioxolane, 1,3-diisopropylbenzene , 1,3-dimethylnaphthalene, 1,4-benzodioxane, 1,4-diisopropylbenzene, 1,4-dimethylnaphthalene, 1,5-dimethyltetralin, 1-benzothiophene, thianaphthalene, 1-bromonaphthalene, 1 -Chloromethylnaphthalene, 1-ethylnaphthalene, 1-methoxynaphthalene, 1-methylnaphthalene, 1-methylindole, 2,3-benzofuran, 2,3-dihydrobenzofuran, 2,3-dimethylanisole, 2,4-dimethyl Anisole, 2,5-dimethylanisole, 2,6-dimethylanisole, 2,6-dimethylnaphthalene, 2-bromo-3-bromomethylnaphthalene, 2-bromomethylnaphthalene, 2-bromonaphthalene, 2-ethoxynaphthalene, 2 -Ethylnaphthalene, 2-isopropylanisole, 2-methylanisole, 2-methylindole, 3,4-dimethylanisole, 3,5-dimethylanisole, 3-bromoquinoline, 3-methylanisole, 4-methylanisole, 5- Decanolide, 5-methoxyindane, 5-methoxyindole, 5-tert-butyl-m-xylene, 6-methylquinoline, 8-methylquinoline, acetophenone, anisole, benzonitrile, benzothiazole, benzyl acetate, bromobenzene, butyl. Benzoate, butylphenyl ether, cyclohexylbenzene, decahydronaphthol, dimethoxytoluene, 3-phenoxytoluene, diphenyl ether, propiophenone, ethylbenzene, ethylbenzoate, hexylbenzene, indane, hexamethylindane, indene, isochroman, cumene, m -Cymene, mesitylene, methylbenzoate, o-, m-, p-xylene, propylbenzoate, propylbenzene, o-dichlorobenzene, pentylbenzene, phenetole, ethoxybenzene, phenylacetate, p-cymene, propiophenone , Sec-butylbenzene, t-butylbenze Amine, thiophene, toluene, veratrol, monochlorobenzene, o-dichlorobenzene, pyridine, pyrazine, pyrimidine, pyrrolidinone, morpholine, dimethylacetamide, dimethylsulfoxide, decalin, and/or mixtures of these compounds.

These solvents can be used individually or as a mixture of two, three or more solvents to form the second solvent.

Preferably, the second solvent has a boiling point in the range 100-400°C, more preferably 150-350°C.

The at least one organic functional material has a solubility in the first and second solvents, preferably in the range of 1 to 250 g/l, more preferably 1 to 50 g/l.

The content of at least one organic functional material in the formulation is in the range of 0.001 to 20% by weight, preferably in the range of 0.01 to 10% by weight, more preferably in the range of 0.001 to 20% by weight, based on the total weight of the formulation. It is in the range of 0.1 to 5% by weight, most preferably 0.3 to 5% by weight.

The formulations according to the invention preferably have a surface tension in the range 10-50 mN/m, more preferably in the range 20-45 mN/m, most preferably in the range 25-40 mN/m.

Furthermore, the formulations according to the invention preferably have a viscosity in the range 1 to 50 mPa·s, more preferably in the range 2 to 40 mPa·s, most preferably in the range 2 to 20 mPa·s.

Preferably, the organic solvent blend comprises a surface tension in the range 15-80 mN/m, more preferably in the range 20-60 mN/m, most preferably in the range 25-40 mN/m. The surface tension can be measured at 20° C. using an FTA (First Ten Angstrom) 1000 contact angle goniometer. Details of the method are described in Roger P. et al. Woodward, Ph. D. Available from First Ten Angstrom, as announced by "Surface Tension Measurements Using the Drop Shape Method". Preferably, the pendant drop method can be used to determine the surface tension. This measurement technique dispenses droplets from a needle in a bulk liquid or gas phase. The shape of the droplet is derived from the relationship between surface tension, gravity, and density difference. Using the pendant drop method, http://www. kruss. The surface tension is calculated from the shadow image of the pendant drop using de/services/education-theory/glossary/drop-shape-analysis. All surface tension measurements were performed using a commonly used and commercially available high precision drop shape analysis tool, FTA 1000 from First Ten Angstrom. The surface tension is determined by the software FTA1000. All measurements were performed at room temperature, which ranged from 20°C to 22°C. Standard operating procedures involve the determination of the surface tension of each formulation using the new disposable drop dispensing system (syringe and needle). Each drop is measured over a 1 minute duration with 60 measurements that are then averaged. Three drops are measured for each formulation. The final value is the average of the measurements. The tool is regularly cross-checked against various liquids with known surface tension.

Formulation and solvent viscosities were measured with a TA instruments ARG2 rheometer using a 40 mm parallel plate structure over a shear rate range of 10-1000 s- ¹ . The measured value was used as an average of 200 to 800 s ⁻¹ , where the temperature and shear rate were precisely controlled. Each solvent is measured 3 times. The viscosity values given are an average of the above measurements.

The formulation according to the invention comprises at least one organic functional material which can be used for the production of functional layers of electronic devices. The functional material is generally an organic material introduced between the anode and cathode of the electronic device.

The term organic functional material means, inter alia, organic conductors, organic semiconductors, organic fluorescent compounds, organic phosphorescent compounds, organic light absorbing compounds, organic photosensitive compounds, organic photosensitizers, and other organic photoactive compounds. To do. The term organofunctional material further includes organometallic complexes of transition metals, rare earths, lanthanides, and actinides.

Organic functional materials include fluorescent emitters, phosphorescent emitters, host materials, matrix materials, exciton blocking materials, electron transport materials, electron injecting materials, hole conducting materials, hole injecting materials, n-dopants, p-dopants, wide. It is selected from the group consisting of bandgap materials, electron blocking materials, and hole blocking materials.

A preferred embodiment of the organic functional material is disclosed in detail in WO2011/073314A1, which is hereby incorporated by reference.

In a preferred embodiment, the organic functional material is an organic semiconductor selected from the group consisting of hole injection, hole transport, light emission, electron transport and electron injection materials.

More preferably, the organic functional material is an organic semiconductor selected from the group consisting of hole injection and hole transport materials.

The organic functional material can be a compound having a low molecular weight, a polymer, an oligomer or a dendrimer, wherein the organic functional material can also be in the form of a mixture. Thus, the formulations according to the invention may comprise two different compounds having a low molecular weight, one compound having a low molecular weight and one polymer, or two polymers (blends).

Organic functional materials are often described by the properties of frontier orbitals, which are described in more detail below. Molecular orbitals, especially the highest occupied molecular orbitals (HOMO) and lowest unoccupied molecular orbitals (LUMO), their energy levels, and the energy of the lowest triplet state T ₁ or lowest excited singlet state S ₁ of the material are determined by quantum chemistry. Determined by calculation. In order to calculate an organic substance containing no metal, first, structural optimization is performed using the “ground state/semi-empirical/default spin/AM1/charge 0/spin singlet” method. Subsequently, energy calculation is performed based on the optimized structure. The "TD-SCF/DFT/default spin/B3PW91" method with the "6-31G(d)" basis set (charge 0, spin singlet) is used here. For metal-containing compounds, the structure is optimized by the "ground state/Hartley Fock/default spin/Lan L2MB/charge 0/spin singlet" method. The energy calculation is performed in the same manner as in the case of the organic substance described above, but the “LanL2DZ” basis set is used for the metal atom and the “6-31G(d)” basis set is used for the ligand. There is a difference that can be. Energy calculation gives the HOMO energy level HEh or the LUMO energy level LEh in Hartley units. The HOMO and LUMO energy levels in electron volts calibrated with reference to cyclic voltammetry measurements are then determined as follows:
HOMO(eV)=((HEh ^* 27.212)-0.9899)/1.1206
LUMO(eV)=((LEh ^* 27.212)-2.0041)/1.385
For purposes of this application, these values shall be considered as the HOMO and LUMO energy levels of the material, respectively.

The lowest triplet state T ₁ is defined as the energy of the triplet state with the lowest energy resulting from the described quantum chemical calculations.

The lowest excited singlet state S ₁ is defined as the energy of the lowest excited singlet state resulting from the described quantum chemistry calculations.

The method described here is independent of the software package used and always gives the same result. Examples of frequently used programs for this purpose are "Gaussian 09W" (Gaussian Inc.) and Q-Chem 4.1 (Q-Chem, Inc.).

Compounds with hole injection properties, also referred to herein as hole injection materials, simplify or facilitate the transfer of holes, ie positive charges, from the anode to the organic layer. The hole injecting material has a HOMO level that lies above the region of the anode level, i.e. generally at least -5.3 eV.

Compounds having hole-transporting properties, also referred to herein as hole-transporting materials, are capable of transporting holes, or positive charges, that are generally injected from the anode or an adjacent layer, such as a hole injection layer. The hole transport material generally has a high HOMO level, preferably at least -5.4 eV. Depending on the structure of the electronic device, it may also be possible to use hole transport materials as hole injection materials.

Preferred compounds having hole injection and/or hole transport properties include, for example, triarylamine, benzidine, tetraaryl-para-phenylenediamine, triarylphosphine, phenothiazine, phenoxazine, dihydrophenazine, thianthrene, dibenzo-para. -Dioxin, phenoxathiyne, carbazole, azulene, thiophene, pyrrole and furan derivatives, further O, S or N containing heterocyclic compounds with high HOMO (HOMO = highest occupied molecular orbital).

As the compound having hole injection and/or hole transport properties, phenylenediamine derivative (US3615404), arylamine derivative (US3567450), amino-substituted chalcone derivative (US3526501), styrylanthracene derivative (JP-A-56-46234), Polycyclic aromatic compound (EP1009041), polyarylalkane derivative (US3615402), fluorenone derivative (JP-A-54-110837), hydrazone derivative (US3717462), acylhydrazone, stilbene derivative (JP-A-61-210363). , A silazane derivative (US4950950), a polysilane (JP-A-2-204996), an aniline copolymer (JP-A-2-282263), a thiophene oligomer (JP-A-1(1989)-212399), polythiophene, poly(N-). Vinylcarbazole) (PVK), polypyrrole, polyaniline, and other conductive polymers, porphyrin compounds (JP-A-63-2959655, US 4720432), aromatic dimethylidene type compounds, carbazole compounds such as CDBP, CBP, mCP, aromatic Particular mention may be made of group tertiary amine and styrylamine compounds (US4127412), for example benzidine-type triphenylamine, styrylamine-type triphenylamine, and diamine-type triphenylamine. Arylamine dendrimer (JP-A-8(1996)-193191), monomeric triarylamine (US3180730), triarylamine containing at least one functional group containing at least one vinyl radical and/or active hydrogen ( It is also possible to use US3567450 and US36558520), or tetraaryldiamines (two tertiary amine units linked via an aryl group). More triarylamino groups may be present in the molecule. Phthalocyanine derivatives, naphthalocyanine derivatives, butadiene derivatives, and quinoline derivatives such as dipyrazino[2,3-f:2',3'-h]quinoxaline hexacarbonitrile are also suitable.

Aromatic tertiary amines containing at least two tertiary amine units (US2008/0102311A1, US4720432 and US5061569), such as NPD (α-NPD=4,4′-bis[N-(1-naphthyl)-N). -Phenyl-amino]biphenyl) (US5061569), TPD232 (=N,N'-bis-(N,N'-diphenyl-4-aminophenyl)-N,N-diphenyl-4,4'-diamino-1, 1′-biphenyl) or MTDATA (MTDATA or m-MTDATA=4,4′,4″-tris[3-methylphenyl)phenylamino]-triphenylamine) (JP-A-4-308688), TBDB( =N,N,N',N'-tetra(4-biphenyl)-diaminobiphenylene), TAPC (=1,1-bis(4-di-p-tolylaminophenyl)cyclo-hexane), TAPPP (=1) , 1-bis(4-di-p-tolylaminophenyl)-3-phenylpropane), BDTAPVB (=1,4-bis[2-[4-[N,N-di(p-tolyl)amino]phenyl ] Vinyl]benzene), TTB (=N,N,N′,N′-tetra-p-tolyl-4,4′-diaminobiphenyl), TPD (=4,4′-bis[N-3-methylphenyl] ]-N-phenylamino)-biphenyl), N,N,N',N'-tetraphenyl-4,4'''-diamino-1,1',4',1'',4'',1 ″″-Quaterphenyl and the like are preferred, as are tertiary amines containing carbazole units, such as TCTA(=4-(9H-carbazol-9-yl)-N,N-bis[4-(9H -Carbazol-9-yl)phenyl]benzenamine) and the like are preferable. Similarly, hexaazatriphenylene compounds according to US 2007/0092755 A1 and phthalocyanine derivatives (eg H ₂ Pc, CuPc (=copper phthalocyanine), CoPc, NiPc, ZnPc, PdPc, FePc, MnPc, ClAlPc, ClGaPc, ClInPc, ClSnPc, Cl _2). SiPc, (HO)AlPc, (HO)GaPc, VOPc, TiOPc, MoOPc, GaPc-O-GaPc) are preferable.

Triarylamine compounds of the following formulas (TA-1) to (TA-12) are particularly preferable, and EP1162193B1, EP650955B1, Synth. Metals 1997,91 (1-3), 209, DE19646119A1, WO2006 / 122630A1, EP1860097A1, EP1834945A1, JP08053397A, US6251531B1, US2005 / 0221124, JP08292586A, US7399537B2, US2006 / 0061265A1, EP1661888, and as disclosed in WO2009 / 041635. The compounds of formulas (TA-1) to (TA-12) may be substituted.

Further compounds which can be used as hole injection materials are described in EP0891121A1 and EP1029909A1 and injection layers are generally described in US2004/0174116A1.

These arylamines and heterocyclic compounds commonly used as hole-injecting and/or hole-transporting materials are preferably above -5.8 eV (relative to vacuum level) in the polymer, particularly preferably It produces a HOMO of greater than -5.5 eV.

Compounds having electron injection and/or electron transport properties include, for example, pyridine, pyrimidine, pyridazine, pyrazine, oxadiazole, quinoline, quinoxaline, anthracene, benzanthracene, pyrene, perylene, benzimidazole, triazine, ketone, phosphine oxide, And phenazine derivatives, and triarylboranes, and further O, S or N containing heterocyclic compounds with low LUMO (LUMO = lowest unoccupied molecular orbital).

Particularly suitable compounds in electron transport and electron injection layer, the metal chelates of 8-hydroxyquinoline (e.g. _{LiQ, AlQ 3, GaQ 3,} MgQ 2, ZnQ 2, InQ 3, ZrQ 4), BAlQ, Ga oxinoid complex, 4- Azaphenanthrene-5-ol-Be complex (US5529853A, see formula ET-1), butadiene derivative (US4356429), heterocyclic optical brightener (US4539507), benzimidazole derivative (US2007/0273272A1), for example TPBI (US5766779, 1,3,5-triazine, such as spirobifluorenyltriazine derivative (for example according to DE 102008064200), pyrene, anthracene, tetracene, fluorene, spirofluorene, dendrimer, tetracene (eg rubrene derivative), 1,10-phenanthroline derivative (JP2003-115387, JP2004-311184, JP2001-267080, WO02/043449), silacyclopentadiene derivative (EP1480280, EP1478032, EP1463953), borane derivative, for example, triarylborane derivative containing Si (US2007). /0087219A1, see formula ET-3), pyridine derivatives (JP2004-200162), phenanthrolines, especially 1,10-phenanthroline derivatives, such as BCP and Bphen, as well as some linked via a biphenyl or other aromatic group. Phenanthroline (US2007-0252517A1) or phenanthroline linked to anthracene (see US2007-0122656A1, formulas ET-4 and ET-5).

Also suitable are heterocyclic organic compounds such as thiopyran dioxide, oxazoles, triazoles, imidazoles or oxadiazoles. N-containing five-membered rings, such as oxazoles, preferably 1,3,4-oxadiazoles, such as the formulas ET-6, ET-7, ET-8 and ET-9 disclosed in, inter alia, US2007/0273272A1. Examples of the use of thiazoles, oxadiazoles, thiadiazoles, triazoles, among others, are described in US2008/0102311A1 and Y. A. Levin, M.; S. See Skorobogatova, Khimiya Geterotsiklischeskikh Soedinenii 1967(2), 339-341, preferably a compound of formula ET-10, a silacyclopentadiene derivative. Preferred compounds are of formulas (ET-6) to (ET-10) below:

It is likewise possible to use organic compounds such as derivatives of fluorenone, fluorenylidene methane, perylene tetracarbonate, anthraquinone dimethane, diphenoquinone, anthrone and anthraquinone diethylenediamine.

Preference is given to 2,9,10-substituted anthracenes (having 1- or 2-naphthyl, and 4- or 3-biphenyl), or molecules containing two anthracene units (see US 2008/0193796A1, formula ET-11). Also very advantageous is the attachment of 9,10-substituted anthracene units to benzimidazole derivatives (see US 2006/147747A and EP 1551206A1, formulas ET-12 and ET-13).

Compounds capable of producing electron injection and/or electron transport properties preferably give LUMOs below -2.5 eV (vs. vacuum level), particularly preferably below -2.7 eV.

The formulations of the present invention may include a phosphor. The term emitter refers to a material that allows a radiative transition to the ground state with emission after excitation, which can occur due to any type of energy transfer. In general, two classes of illuminants are known: fluorescent and phosphorescent emitters. The term fluorescent emitter refers to a material or compound that undergoes a radiative transition from the excited singlet state to the ground state. The term phosphorescent emitter means a luminescent material or compound that preferably contains a transition metal.

An emitter is often referred to as a dopant if the dopant causes the above properties in the system. Dopant in a system comprising matrix material and dopant is taken to mean the component with the lower proportion of the mixture. Correspondingly, matrix material in a system containing matrix material and dopant is taken to mean the component with the higher proportion of the mixture. Thus, the term phosphorescent emitter can also be taken to mean, for example, a phosphorescent dopant.

Compounds capable of emitting light include fluorescent and phosphorescent emitters, among others. These include stilbene, stilbene amine, styryl amine, coumarin, rubrene, rhodamine, thiazole, thiadiazole, cyanine, thiophene, paraphenylene, perylene, phthalocyanine, porphyrins, ketones, quinolines, imines, anthracenes and/or pyrenes, among others. Includes compounds containing structures. Particularly preferred are compounds that are capable of emitting light from the triplet state with high efficiency even at room temperature, that is, they exhibit electrophosphorescence, which often leads to increased energy efficiency, rather than electrofluorescence. Suitable for this purpose are, first of all, compounds containing heavy atoms with an atomic number greater than 36. Compounds containing a d- or f-transition metal satisfying the above conditions are preferred. Corresponding compounds containing elements of groups 8-10 (Ru, Os, Rh, Ir, Pd, Pt) are particularly preferred here. Suitable functional compounds here are, for example, the various complexes described in WO02/068435A1, WO02/081488A1, EP1239526A2 and WO2004/026886A2.

Preferred compounds that can function as fluorescent emitters are described by the examples below. Preferred fluorescent emitters are selected from the class of monostyrylamines, distyrylamines, tristyrylamines, tetrastyrylamines, styrylphosphines, styryl ethers, and arylamines.

Monostyrylamine is taken to mean a compound which contains one substituted or unsubstituted styryl group and at least one, preferably aromatic amine. Distyrylamine is taken to mean a compound which contains two substituted or unsubstituted styryl groups and at least one, preferably aromatic amine. Tristyrylamine is taken to mean a compound which contains three substituted or unsubstituted styryl groups and at least one, preferably aromatic amine. Tetrastyrylamine is taken to mean a compound which contains four substituted or unsubstituted styryl groups and at least one, preferably aromatic amine. The styryl group is particularly preferably stilbene, which may be further substituted. Corresponding phosphines and ethers are defined similarly to amines. Arylamines or aromatic amines in the sense of the present invention are taken to mean compounds which contain three substituted or unsubstituted aromatic or heteroaromatic ring systems directly bonded to the nitrogen. Preferably, at least one of these aromatic or heteroaromatic ring systems is a fused ring system, preferably having at least 14 aromatic ring atoms. Preferred examples of these are aromatic anthracene amines, aromatic anthracene diamines, aromatic pyrene amines, aromatic pyrenediamines, aromatic chrysenamines, or aromatic chrysenediamines. Aromatic anthracene amine is taken to mean a compound in which one diarylamino group is bonded directly to the anthracene group, preferably in the 9-position. Aromatic anthracene diamine is taken to mean a compound in which two diarylamino groups are preferably attached directly to the anthracene group in the 2,6 or 9,10 positions. Aromatic pyrene amines, pyrenediamines, chrysenamines, and chrysenediamines are similarly defined herein, where the diarylamino group is preferably attached to the pyrene in the 1- or 1,6-position.

Further preferred fluorescent emitters are especially the indenofluorene amines or indenofluorenediamines described in WO 2006/122630; the benzoindenofluorenamines or benzoindenofluorenediamines described in WO 2008/006449; and especially WO 2007/140847. Selected from dibenzoindenofluorenamine or dibenzoindenofluorenediamine.

Examples of compounds from the class of styrylamines that can be used as fluorescent emitters are the substituted or unsubstituted tristilbenamines or the dopants described in WO 2006/000388, WO 2006/058737, WO 2006/000389, WO 2007/065549 and WO 2007/115610. is there. Distyrylbenzene and distyrylbiphenyl derivatives are described in US5121029. Further styrylamines can be found in US2007/0122656A1.

Particularly preferred styrylamine compounds are the compounds of formula EM-1 described in US 7250532B2 and the compounds of formula EM-2 described in DE 102005058557A1:

Particularly preferred triarylamine compounds are CN1583691A, JP08/053397A and US6251531B1, EP19557606A1, US2008/0113101A1, US2006/210830A, WO2008/006449, and compounds of formulas EM-3 to EM-15 and their derivatives disclosed in DE102008035413. Is:

Further preferred compounds which can be used as fluorescent emitters are naphthalene, anthracene, tetracene, benzoanthracene, benzophenanthrene (DE102009005746), fluorene, fluoranthene, periflanten, indenoperylene, phenanthrene, perylene (US2007/0252517A1), pyrene, chrysene, decacyclene. , Coronene, tetraphenylcyclopentadiene, pentaphenylcyclopentadiene, fluorene, spirofluorene, rubrene, coumarin (US4769292, US6020078, US2007/0252517A1), pyran, oxazole, benzoxazole, benzothiazole, benzimidazole, pyrazine, cinnamic acid ester , Diketopyrrolopyrrole, acridone, and quinacridone (US2007/0252517A1) derivatives.

Among the anthracene compounds, 9,10-substituted anthracenes such as 9,10-diphenylanthracene and 9,10-bis(phenylethynyl)anthracene are particularly preferable. 1,4-bis(9'-ethynylanthracenyl)-benzene is also a preferred dopant.

Similarly, derivatives of rubrene, coumarin, rhodamine, quinacridone, such as DMQA (=N,N'-dimethylquinacridone), dicyanomethylenepyran, such as DCM (=4-(dicyanoethylene)-6-(4-dimethylaminostyryl). 2-Methyl)-4H-pyran) and the like, thiopyran, polymethine, pyrylium and thiapyrylium salts, perifranthene, and indenoperylene are preferred.

Blue fluorescent emitters are preferably polyaromatic compounds such as 9,10-di(2-naphthylanthracene) and other anthracene derivatives, such as tetracene, xanthene, derivatives of perylene, such as 2,5,8,11-tetra. Phenylene such as -t-butylperylene, for example, 4,4'-bis(9-ethyl-3-carbazovinylene)-1,1'-biphenyl, fluorene, fluoranthene, arylpyrene (US2006/0222886A1), arylene vinylene (US5121029, US5130603), bis(azinyl)imine-boron compound (US2007/0092753A1), bis(azinyl)methene compound, and carbostyryl compound.

Further preferred blue fluorescent emitters are C.I. H. Chen et al.: "Recent developments in organic electroluminescent materials" Macro-mol. Symp. 125, (1997) 1-48 and "Recent progress of molecular organic electroluminescent materials and devices" Mat. Sci. and Eng. R, 39 (2002), 143-222.

Further preferred blue fluorescent emitters are the hydrocarbons disclosed in DE 102008035413.

Preferred compounds that can function as phosphorescent emitters are described by the examples below.

Examples of phosphorescent emitters are disclosed in WO00/70655, WO01/41512, WO02/02714, WO02/15645, EP1191613, EP1191612, EP1191614, and WO2005/033244. In general, all phosphorescent complexes used in phosphorescent OLEDs according to the prior art and known to the person skilled in the art of organic electroluminescence are suitable, the person skilled in the art being able to obtain further phosphorescent complexes without inventive step. Can be used.

The phosphorescent metal complex preferably contains Ir, Ru, Pd, Pt, Os or Re, more preferably Ir.

Preferred ligands are 2-phenylpyridine derivative, 7,8-benzoquinoline derivative, 2-(2-thienyl)pyridine derivative, 2-(1-naphthyl)pyridine derivative, 1-phenylisoquinoline derivative, 3-phenylisoquinoline. It is a derivative or a 2-phenylquinoline derivative. All of these compounds may be substituted for the blue color, for example with fluoro, cyano and/or trifluoromethyl substituents. The ancillary ligand is preferably acetylacetonate or picolinic acid.

Particularly suitable are complexes of Pt or Pd with a tetradentate ligand of formula EM-16.

Compounds of formula EM-16 are described in more detail in US2007/0087219A1, which is hereby incorporated by reference for the purpose of disclosure for the explanation of substituents and subscripts in the above formulas. Furthermore, a Pt-porphyrin complex (US2009/0061681A1) having an extended ring system and an Ir complex such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin-Pt(II), tetraphenyl -Synthesis of Pt (II) tetrabenzoporphyrin (US2009 / 0061681A1), cis- bis ^{(2-phenylpyridinato--N, C 2 ') Pt (} II), cis- bis (2- (2'-thienyl) pyridinato ^{-N, C 3 ') Pt (} II), cis- bis (2- (2'-thienyl) - quinolinato ^{-N, C 5') Pt (} II), (2- (4,6- difluorophenyl) pyridinato ^{-N, C 2 ') Pt (} II) ( acetylacetonate), or tris ^{(2-phenylpyridinato--N, C 2') Ir (} III) (= Ir (ppy) 3, green), bis ^{(2-phenylpyridinato--N, C 2) Ir (III} ) ( _{acetylacetonate)} (= Ir (ppy) ₂ acetylacetonate, green, US2001 / 0053462A1, Baldo, Thompson et al., Nature 403, (2000) , 750-753), bis (1-phenylisoquinolinato--N, ^{C 2} ') (2-phenylpyridinato--N, ^{C 2')} iridium (III), bis (2-phenylpyridinato--N , C ² ′)(1-phenylisoquinolinato-N,C ² ′)iridium(III), bis(2-(2′-benzothienyl)pyridinato-N,C ³ ′)iridium(III) (acetylaceto Nato), bis(2-(4′,6′-difluorophenyl)pyridinato-N,C ² ′)iridium(III) (picolinate) (FIrpic, blue), bis(2-(4′,6′-difluoro) phenyl) pyridinato ^{-N, C 2 ') Ir (} III) ( tetrakis (1- pyrazolyl) borate), tris (2- (biphenyl-3-yl) -4-tert-butyl pyridine) iridium (III), (ppz _{) 2 Ir (5phdpym) (US2009} / 0061681A1), (45ooppz) 2 Ir (5phdpym) (US2009 / 0061681A1), derivatives of 2-phenylpyridine -Ir complexes such PQIr (= iridium (III) bis (2-Fenirukino Lil -N, ^{C 2} ') acetylacetonate) and the like, tris (2-Feniruisoki Norinato-N,C)Ir(III) (red), bis(2-(2′-benzo[4,5-a]thienyl)pyridinato-N,C ³ )Ir(acetylacetonate)([Btp ₂ Ir (Acac)], red, Adachi et al., Appl. Phys. Lett. 78 (2001), 1622-1624).

Also suitable are trivalent lanthanides, eg complexes such as Tb ³⁺ and Eu ³⁺ (J. Kido et al., Appl. Phys. Lett. 65 (1994), 2124, Kido et al., Chem. Lett. 657, 1990, US2007/0252517A1) or a phosphorescent complex of Pt(II), Ir(I), Rh(I) containing maleonitrile dithiolate (Johnson et al., JACS 105, 1983, 1795), Re(I) tricarbonyl-diimine complex. (Especially Wrightton, JACS96, 1974, 998), Os(II) complexes with cyano ligands and bipyridyl or phenanthroline ligands (Ma et al., Synth. Metals 94, 1998, 245).

Further phosphorescent emitters with tridentate ligands are described in US6824895 and US10/729238. Red emitting phosphorescent complexes are found in US6835469 and US6830828.

Particularly preferred compounds used as phosphorescent dopants are, inter alia, US 2001/0053462 A1 and Inorg. Chem. 2001, 40(7), 1704-1711, JACS 2001, 123(18), 4304-431, and compounds of formula EM-17.

Derivatives are described in US7378162B2, US6835469B2 and JP2003/253145A.

Furthermore, the compounds of the formulas EM-18 to EM-21 and their derivatives described in US7238437B2, US2009/008607A1 and EP1348711 can be used as emitters.

Similarly, quantum dots can be used as light emitters and these materials are disclosed in detail in WO2011/073314A1.

In particular, compounds used as host materials with light emitting compounds include materials from various classes of materials.

The host material generally has a larger bandgap between HOMO and LUMO than the phosphor material used. In addition, preferred host materials exhibit properties of either hole or electron transport materials. In addition, the host material can have both electron and hole transport properties.

The host material is optionally also referred to as matrix material, especially when the host material is used in combination with a phosphorescent emitter in an OLED.

Preferred host materials or co-host materials used in particular with fluorescent dopants are oligoarylenes (eg 2,2′,7,7′-tetraphenylspirobifluorene according to EP 676461, or dinaphthylanthracene), especially fused aromatic groups. Containing oligoarylene, for example, anthracene, benzanthracene, benzophenanthrene (DE102009005746, WO2009/0695666), phenanthrene, tetracene, coronene, chrysene, fluorene, spirofluorene, perylene, phthaloperylene, naphthaloperylene, decacyclene, rubrene, etc., for example oligoarylenevinylene. DPVBi=4,4′-bis(2,2-diphenylethenyl)-1,1′-biphenyl or spiro-DPVBi) according to EP 676461, polypodal metal complexes (eg according to WO 04/081017), especially the metal of 8-hydroxyquinoline. A metal complex of, for example, AlQ ₃ (=aluminum(III) tris(8-hydroxyquinoline)) or bis(2-methyl-8-quinolinolato)-4-(phenylphenolinolato)aluminum, further comprising an imidazole chelate. (US2007/0092753A1), and quinoline metal complex, aminoquinoline-metal complex, benzoquinoline-metal complex, hole-conducting compound (for example, according to WO2004/058911), electron-conducting compound, especially ketone, phosphine oxide, sulfoxide It is selected from the class of (eg according to WO 2005/084081 and WO 2005/084082), atropisomers (eg according to WO 2006/048268), boronic acid derivatives (eg according to WO 2006/117052) or benzanthracenes (eg according to WO 2008/145239).

Particularly preferred compounds that can function as host or cohost materials are selected from the oligoarylenes containing anthracene, benzanthracene and/or pyrene, or the atropisomeric class of these compounds. Oligoarylene in the sense of the present invention is intended to be understood to mean a compound in which at least three aryl or arylene groups are bound to one another.

Preferred host materials are especially selected from compounds of formula (H-1)

(Wherein Ar ⁴ , Ar ⁵ , and Ar ⁶ are the same or different each time they appear, and are an aryl or heteroaryl group having 5 to 30 aromatic ring atoms which may be optionally substituted. And p represents an integer in the range of 1 to 5; the total of π electrons in Ar ⁴ , Ar ⁵ and Ar ⁶ is at least 30 if p=1, at least 36 if p=2, p= 3 is at least 42).

In the compound of formula (H-1), the Ar ⁵ group particularly preferably represents anthracene, and the Ar ⁴ and Ar ⁶ groups are linked at the 9 and 10 positions, wherein these groups are optionally It may be substituted. Very particularly preferably, at least one of the Ar ⁴ and/or Ar ⁶ groups is 1- or 2-naphthyl, 2-, 3- or 9-phenanthrenyl, or 2-, 3-, 4-, 5-, 6 Or a fused aryl group selected from 7-benzanthracenyl. The anthracene compounds are described in US2007/0092753A1 and US2007/0252517A1, and for example, 2-(4-methylphenyl)-9,10-di-(2-naphthyl)anthracene, 9-(2-naphthyl)-10. -(1,1'-biphenyl)anthracene and 9,10-bis[4-(2,2-diphenylethenyl)phenyl]anthracene, 9,10-diphenylanthracene, 9,10-bis(phenylethynyl)anthracene, And 1,4-bis(9'-ethynylanthracenyl)benzene. A compound containing two anthracene units (US2008/0193796A1), for example 10,10′-bis[1,1′,4′,1″]terphenyl-2-yl-9,9′-bisanthracenyl. Is also preferable.

Further preferred compounds are arylamine, styrylamine, fluorescein, diphenylbutadiene, tetraphenylbutadiene, cyclopentadiene, tetraphenylcyclopentadiene, pentaphenylcyclopentadiene, coumarin, oxadiazole, bisbenzoxazoline, oxazole, pyridine, pyrazine, imine. , Benzothiazole, benzoxazole, a derivative of benzimidazole (US2007/0092753A1), for example, 2,2′,2″-(1,3,5-phenylene)tris[1-phenyl-1H-benzimidazole], aldazine, Stilbene, styrylarylene derivatives such as 9,10-bis[4-(2,2-diphenylethenyl)-phenyl]anthracene, and distyrylarylene derivatives (US5121029), diphenylethylene, vinylanthracene, diaminocarbazole, pyran, thiopyran. , Diketopyrrolopyrrole, polymethine, cinnamic acid esters, and fluorescent dyes.

Arylamine and styrylamine derivatives such as TNB (=4,4'-bis[N-(1-naphthyl)-N-(2-naphthyl)amino]biphenyl) are particularly preferred. Metal oxinoid complexes, for example LiQ or AlQ ₃ can be used as Kohosuto.

Preferred compounds containing oligoarylene as a matrix include US2003/0027016A1, US732326371B2, US2006/043858A, WO2007/114358, WO2008/145239, JP3148176B2, EP1009044, US2004/018383, WO2005/061656US7,080620001, WO068102001, WO06/084105001, WO1,08062001503, WO06/20160730A, WO06/16820001, WO06/114070, and WO06/114070. 0656678, and DE 102009005746, in which particularly preferred compounds are described by formulas H-2 to H-8.

In addition, compounds that can be used as a host or matrix include materials used with phosphorescent emitters.

These compounds can also be used as structural elements in polymers, such as CBP (N,N-biscarbazolylbiphenyl), carbazole derivatives (eg WO2005/039246, US2005/0069729, JP2004/288381, EP1205527 or WO2008/ 086851), azacarbazole (eg according to EP1617710, EP1617711, EP1731584 or JP2005/347160), ketones (eg according to WO2004/093207 or DE10200803393943), phosphine oxides, sulfoxides and sulfones (eg according to WO2005/003253), oligophenylenes, aromatics. Amines (for example according to US 2005/0069729), bipolar matrix materials (for example according to WO 2007/137725), silanes (for example according to WO 2005/111172), 9,9-diarylfluorene derivatives (for example according to DE 102008017591), azaboroles or boronates (for example according to DE 102008017591). WO 2006/117052), triazine derivatives (for example according to DE 1020080369982), indolocarbazole derivatives (for example according to WO 2007/063754 or WO 2008/056746), indenocarbazole derivatives (for example according to DE 102009023155 and DE 1020099031021), diazaphosphole derivatives (for example according to DE1020099022858), Triazole derivative, oxazole and oxazole derivative, imidazole derivative, polyarylalkane derivative, pyrazoline derivative, pyrazolone derivative, distyrylpyrazine derivative, thiopyran dioxide derivative, phenylenediamine derivative, tertiary aromatic amine, styrylamine, amino-substituted chalcone Derivatives, indole, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic dimethylidene compounds, carbodiimide derivatives, metal complexes of 8-hydroxyquinoline derivatives which may further contain triarylaminophenol ligands, for example AlQ ₃ (US2007/ 0134514A1), metal complexes/polysilane compounds, and thiophene, benzothiophene and dibenzothiophene derivatives.

An example of a preferred carbazole derivative is mCP (=1,3-N,N-di-carbazolylbenzene (=9,9'-(1,3-phenylene)bis-9H-carbazole)) (formula H-9 ), CDBP (=9,9′-(2,2′-dimethyl[1,1′-biphenyl]-4,4′-diyl)bis-9H-carbazole), 1,3-bis(N,N′) -Dicarbazolyl)benzene (=1,3-bis(carbazol-9-yl)benzene), PVK (polyvinylcarbazole), 3,5-di(9H-carbazol-9-yl)biphenyl, and CMTTP (formula H-10). ). Particularly mentioned compounds are disclosed in US2007/0128467A1 and US2005/0249976A1 (formula H-11 and H-13).

Preferred tetraaryl-Si compounds are described, for example, in US2004/0209115, US2004/0209116, US2007/0087219A1, and H.S. Gilman, E.; A. Zuech, Chemistry & Industry (London, United Kingdom), 1960, 120.

Particularly preferred tetraaryl-Si compounds are described by formulas H-14 to H-21.

Particularly preferred compounds from Group 4 for the preparation of matrices for phosphorescent dopants are disclosed inter alia in DE102009022858, DE102009023155, EP652273B1, WO2007/063754 and WO2008/056746, wherein particularly preferred compounds are of formula H-22 to It is described by H-25.

With regard to the functional compounds which can be used according to the invention and which can function as host materials, substances containing at least one nitrogen atom are particularly preferred. These preferably include aromatic amines, triazine derivatives and carbazole derivatives. Therefore, the carbazole derivative exhibits particularly surprisingly high efficiency. Triazine derivatives provide unexpectedly long life of electronic devices.

It may also be preferable to use a plurality of different matrix materials, in particular at least one electron-conducting matrix material and at least one hole-conducting matrix material, as a mixture. The use of mixtures of charge transport matrix materials with electrically inactive matrix materials that participate in charge transport but not to a significant extent, as described in WO 2010/108579, is likewise preferred. ..

It is further possible to use compounds that improve the transition from the singlet state to the triplet state and are used to support functional compounds with phosphor properties and improve the phosphorescence properties of these compounds. Suitable for this purpose are in particular carbazole and bridged carbazole dimer units, as described for example in WO 2004/070772 A2 and WO 2004/113468 A1. Also suitable for this purpose are ketones, phosphine oxides, sulphoxides, sulphones, silane derivatives and similar compounds, for example as described in WO2005/040302A1.

Here, n-dopant is taken to mean a reducing agent, ie an electron donor. Preferred examples of n-dopants are W(hpp) ₄ and other electron-rich metal complexes according to WO2005/086251A2, P=N compounds (eg WO2012/175535A1, WO2012/175219A1), naphthylenecarbodiimides (eg WO2012/168358A1), fluorene. (Eg WO2012/031735A1), free radicals and diradicals (eg EP1837926A1, WO2007/107306A1), pyridine (eg EP2452946A1, EP2463927A1), N-heterocyclic compounds (eg WO2009/000237A1), and acridine and phenazine (eg US2007/145355A1). ).

Further, the formulation may include a wide bandgap material as a functional material. A wide bandgap material is taken to mean a material within the meaning of the disclosure of US 7,294,849. These systems exhibit particularly advantageous performance data in electroluminescent devices.

The compound used as the wide bandgap material can preferably have a bandgap of 2.5 eV or higher, preferably 3.0 eV or higher, particularly preferably 3.5 eV or higher. The band gap can be calculated by the energy levels of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO), among others.

Further, the formulation may include a hole blocking material (HBM) as a functional material. Hole-blocking material means a material that prevents or minimizes the transfer of holes (positive charges) in a multilayer system, especially when this material is arranged in the form of a layer adjacent to the light-emitting layer or the hole-conducting layer. .. Generally, the hole blocking material has a lower HOMO level than the hole transporting material in the adjacent layer. The hole blocking layer is often located in the OLED between the light emitting layer and the electron transport layer.

In principle, any known hole blocking material can be used. In addition to other hole blocking materials described elsewhere in this application, an advantageous hole blocking material is a metal complex (US2003/0068528) such as bis(2-methyl-8-quinolinolato)(4-phenylpheno). Lato) Aluminum (III) (BAlQ) and the like. Fac-Tris(1-phenylpyrazolato-N,C2)-iridium(III)(Ir(ppz) ₃ ) has also been used for this purpose (US2003/01775553A1). Phenanthroline derivatives such as BCP or phthalimides such as TMPP can be used as well.

Further advantageous hole blocking materials are described in WO00/70655A2, WO01/41512 and WO01/93642A1.

Further, the formulation may include an electron blocking material (EBM) as a functional material. An electron blocking material means a material that prevents or minimizes the transfer of electrons in a multilayer system, especially when this material is arranged in the form of a layer adjacent to the light emitting layer or the electron conducting layer. Generally, electron blocking materials have a higher LUMO level than electron transporting materials in adjacent layers.

In principle, any known electron blocking material can be used. In addition to other electron blocking materials described elsewhere in this application, advantageous electron blocking materials are transition metal complexes such as Ir(ppz) ₃ (US2003/01755553).

The electron blocking material can preferably be selected from amines, triarylamines and their derivatives.

Further, the functional compound that can be used as an organic functional material in the formulation is preferably 3,000 g/mol or less, more preferably 2,000 g/mol or less, and most preferably 1,000 g/mol, when it is a low molecular weight compound. It has the following molecular weights:

Of particular interest are further functional compounds characterized by a high glass transition temperature. In this connection, particularly preferred functional compounds which can be used as organic functional materials in the formulations have a glass transition temperature of 70° C. or higher, preferably 100° C. or higher, more preferably 125° C. or higher, most preferably a glass transition temperature determined according to DIN 51005. It is more than 150°C.

The formulation may further include a polymer as the organic functional material. The compounds described above as organic functional materials often have a relatively low molecular weight and can also be mixed with polymers. It is likewise possible to incorporate these compounds covalently into the polymer. This is possible in particular with compounds which are substituted by reactive leaving groups such as bromine, iodine, chlorine, boronic acids or boronic esters, or reactive polymerizable groups such as olefins or oxetanes. These can be used as monomers for the production of the corresponding oligomers, dendrimers or polymers. Oligomerization or polymerisation here preferably takes place by means of halogen functionality or boronic acid functionality or by polymerisable groups. Furthermore, it is possible to crosslink the polymer via groups of this kind. The compounds and polymers according to the invention can be used as crosslinked or non-crosslinked layers.

Polymers which can be used as organic functional materials often contain the units or structural elements mentioned in the context of the compounds mentioned above, in particular those disclosed and broadly described in WO 02/0777060 A1, WO 2005/014689 A2 and WO 2011/073314 A1. These are incorporated herein by reference. The functional material can be, for example, from the following classes:
Group 1: Structural elements capable of producing hole injection and/or hole transport properties;
Group 2: Structural elements capable of producing electron injection and/or electron transport properties;
Group 3: Structural elements that combine the properties described in relation to Group 1 and Group 2;
Group 4: Luminescent properties, especially structural elements with phosphorescent groups;
Group 5: Structural elements improving the transition from the so-called singlet state to the triplet state;
Group 6: Structural elements that influence the morphology or emission color of the resulting polymer;
Group 7: Structural elements typically used as scaffolds.

The structural elements here may also have various functions, and explicit allocation does not have to be advantageous. For example, the structural elements of group 1 may function as a skeleton as well.

The polymers with hole transporting or hole injecting properties used as organic functional materials containing structural elements from Group 1 preferably also contain units corresponding to the hole transporting or hole injecting materials described above. Good.

Further preferred structural elements of group 1 are, for example, triarylamines, benzidines, tetraaryl-para-phenylenediamines, carbazoles, azulenes, thiophenes, pyrroles and furan derivatives, and further O-, S- or N-containing heterocycles with high HOMO. It is a cyclic compound. These arylamines and heterocyclic compounds preferably have a HOMO above -5.8 eV (vs. vacuum level), particularly preferably above -5.5 eV.

Especially preferred are polymers having hole transporting or hole injecting properties containing at least one repeating unit of formula HTP-1 below:

Where the symbols have the following meanings:
Ar ¹ is in each case the same or different for different repeating units, is a single bond or is an optionally substituted mono- or polycyclic aryl group;
Ar ² is in each case the same or different for different repeating units and is an optionally substituted mono- or polycyclic aryl radical;
Ar ³ is in each case the same or different for different repeating units and is an optionally substituted mono- or polycyclic aryl group;
m is 1, 2 or 3.)

Particularly preferred are repeating units of HTP-1 selected from the group consisting of units of formulas HTP-1A to HTP-1C:

Where the symbols have the following meanings:
R ^a is the same or different at each occurrence, and is H, a substituted or unsubstituted aromatic or heteroaromatic group, an alkyl, cycloalkyl, alkoxy, aralkyl, aryloxy, arylthio, alkoxycarbonyl, silyl or carboxyl group. A halogen atom, a cyano group, a nitro group, or a hydroxy group;
r is 0, 1, 2, 3 or 4;
s is 0, 1, 2, 3, 4 or 5.)

Especially preferred are polymers with hole-transporting or hole-injecting properties which contain at least one repeating unit of formula HTP-2 below:

Where the symbols have the following meanings:
T ¹ and T ² are independently selected from thiophene, selenophene, thieno[2,3-b]thiophene, thieno[3,2-b]thiophene, dithienothiophene, pyrrole and aniline, where these The group may be substituted by one or more radicals R ^b ;
Each time R ^b appears, halogen, —CN, —NC, —NCO, —NCS, —OCN, —SCN, —C(═O)NR ⁰ R ⁰⁰ , —C(═O)X, —C( _{^{= O) R 0, -NH 2}} , -NR 0 R 00, -SH, -SR 0, -SO 3 H, -SO 2 R 0, -OH, -NO 2, -CF 3, -SF 5, optionally Independently from an optionally substituted silyl, carbyl or hydrocarbyl group having 1 to 40 carbon atoms, optionally substituted with 1 or more heteroatoms. Selected;
R ⁰ and R ⁰⁰ are each independently H, or optionally substituted having 1-40 carbon atoms, which may be optionally substituted and optionally contain one or more heteroatoms. A carbyl or hydrocarbyl group which may be
Ar ⁷ and Ar ⁸ are, independently of each other, monocyclic or polycyclic, optionally substituted and optionally bonded to the 2,3 position of one or both of the adjacent thiophene or selenophene groups. Represents a cyclic aryl or heteroaryl group;
c and e are, independently of each other, 0, 1, 2, 3 or 4, where 1<c+e≦6;
d and f are 0, 1, 2, 3 or 4 independently of each other).

Preferred examples of polymers having hole-transporting or hole-injecting properties are described inter alia in WO2007/131582A1 and WO2008/009343A1.

The polymers with electron injection and/or electron transport properties used as organic functional materials containing structural elements from group 2 preferably also contain units corresponding to the electron injection and/or electron transport materials described above. Good.

Further preferred structural elements of group 2 having electron injection and/or electron transport properties are, for example, pyridine, pyrimidine, pyridazine, pyrazine, oxadiazole, quinoline, quinoxaline and phenazine groups, also triarylborane groups, or low LUMO quasi groups. Derived from an additional O, S or N containing heterocyclic compound having a position. These Group 2 structural elements preferably have a LUMO of less than -2.7 eV (vs. vacuum level), particularly preferably less than -2.8 eV.

The organic functional material may preferably be a polymer containing structural elements from group 3 wherein the structural elements improving hole and electron mobility (ie structural elements from groups 1 and 2) are , Directly linked to each other. Some of these structural elements can function as light emitters, where the emission color may be shifted, for example to green, red or yellow. Thus, their use is advantageous, for example, for the production of other emission colors or broad band emission by polymers which naturally emit blue.

The polymers having luminescent properties which are used as organic functional materials containing structural elements from group 4 may preferably contain units corresponding to the abovementioned phosphor materials. Preference is given here to polymers containing the abovementioned light-emitting metal complexes which contain corresponding units containing phosphorescent groups, in particular elements of the groups 8-10 (Ru, Os, Rh, Ir, Pd, Pt).

Polymers used as organic functional materials containing units of group 5 which improve the transition from the so-called singlet state to the triplet state can preferably be used for supporting phosphorescent compounds, preferably the groups mentioned above. It is a polymer containing 4 structural elements. Polymer triplet matrices can be used here.

Suitable for this purpose are in particular carbazole and linked carbazole dimer units, as described, for example, in DE 10304819 A1 and DE 10328627 A1. Also suitable for this purpose are, for example, ketones, phosphine oxides, sulfoxides, sulfone and silane derivatives, as described in DE 10349033A1, and similar compounds. In addition, preferred structural units can be derived from the compounds described above in connection with the matrix material used with the phosphorescent compound.

The further organic functional material is preferably a polymer containing units of group 6 which influence the morphology of the polymer or the emission color. Besides the polymers mentioned above, these are those which have at least one further aromatic or another conjugated structure not counted in the above groups. Therefore, these groups have little or no effect on charge carrier mobility, non-organometallic complexes, or singlet-triplet migration.

Structural units of this kind can influence the morphology or emission color of the resulting polymer. Therefore, depending on the structural unit, these polymers can also be used as emitters.

Thus, for fluorescent OLEDs, aromatic structural elements having 6 to 40 C atoms or tolan, stilbene or bisstyrylarylene derivative units are preferred, each of which may be substituted by one or more radicals. .. Here, 1,4-phenylene, 1,4-naphthylene, 1,4- or 9,10-anthrylene, 1,6-, 2,7- or 4,9-pyrenylene, 3,9- or 3,10. -Perylenylene, 4,4'-biphenylene, 4,4''-terphenylylene, 4,4'-bi-1,1'-naphthylene, 4,4'-tranylene, 4,4'-stilbenylene, or 4,4 Particularly preferred is the use of groups derived from ″-bisstyrylarylene derivatives.

The polymers used as organic functional materials preferably contain units of group 7 and preferably aromatic structures with 6 to 40 C atoms, which are often used as skeletons.

These are, inter alia, 4,5-dihydropyrene derivatives, 4,5,9,10-tetra-hydropyrene derivatives, fluorene derivatives, such as those disclosed in, for example, US5962631, WO2006/052457A2 and WO2006/118345A1, eg WO2003/020790A1. 9,9-spirobifluorene derivatives, such as the 9,10-phenanthrene derivatives disclosed in WO2005/104264A1, such as the 9,10-dihydrophenanthrene derivatives disclosed in WO2005/014689A2, such as WO2004/041901A1 and 5,7-dihydrodibenzooxepin derivatives and cis- and trans-indenofluorene derivatives disclosed in WO 2004/113412 A2, as well as the binaphthylene derivatives disclosed in WO 2006/063852 A1, and for example WO 2005/056633 A1, EP 1344788 A1, It comprises further units as disclosed in WO2007/043495A1, WO2005/033174A1, WO2003/099901A1 and DE102006003710.

For example, the fluorene derivatives disclosed in US 5,962,631, WO 2006/052457A2 and WO 2006/118345A1, such as the spirobifluorene derivatives disclosed in WO2003/020790A1, such as WO2005/056633A1, EP1344788A1 and WO2007/043495A1. Particularly preferred are the structural units of Group 7 selected from the group consisting of benzofluorene, dibenzofluorene, benzothiophene and dibenzofluorene groups and their derivatives.

Particularly preferred group 7 structural elements are represented by the general formula PB-1:

(Where the symbols and subscripts have the following meanings:
A, respectively B and B ', also have the same or different for different repeating units, preferably ^{-CR c R d -, - NR} c -, - PR c -, - O -, - _{S -, - SO -, -} SO 2-, -CO -, - CS -, - cSe -, - P (= O) R c -, - P (= S) R c - and -SiR ^c R ^d - A divalent group selected from:
R ^c and R ^d are H, halogen, —CN, —NC, —NCO, —NCS, —OCN, —SCN, —C(═O)NR ⁰ R ⁰⁰ , —C(═O) each time they appear. _{^{X, -C (= O) R}} 0, -NH 2, -NR 0 R 00, -SH, -SR 0, -SO 3 H, -SO 2 R 0, -OH, -NO 2, -CF 3, -SF ₅ , an optionally substituted silyl, carbyl or hydrocarbyl group having from 1 to 40 carbon atoms, which may be optionally substituted and optionally contain one or more heteroatoms. Independently selected from R ^c and R ^{d, which} may optionally form a spiro group with the fluorene radical to which they are attached;
X is halogen;
R ⁰ and R ⁰⁰ are each independently H, or optionally substituted having 1-40 carbon atoms, which may be optionally substituted and optionally contain one or more heteroatoms. A carbyl or hydrocarbyl group which may be
g is in each case independently 0 or 1, h is in each case independently 0 or 1, where the sum of g and h in the subunits is preferably 1. ;
m is an integer of 1 or more;
Ar ¹ and Ar ² are independently of each other optionally mono- or polycyclic aryl or optionally substituted at the 7,8-position or the 8,9-position of indenofluorene or Represents a heteroaryl group;
a and b are 0 or 1 independently of each other).

If the R ^c and R ^d groups form a spiro group together with the fluorene group to which these groups are attached, this group preferably represents spirobifluorene.

Particularly preferred are repeating units of formula PB-1 selected from the group consisting of units of formulas PB-1A to PB-1E:

Where R ^c has the meaning given above for formula PB-1, r is 0, 1, 2, 3 or 4 and R ^e has the same meaning as the radical R ^c. ..

R ^e is preferably _{-F, -Cl, -Br, -I,} -CN, -NO 2, -NCO, -NCS, -OCN, -SCN, -C (= O) NR 0 R 00, -C ^{(= O) X, -C (} = O) R 0, -NR 0 R 00, 4~40 , preferably substituted optionally with 6-20 C atoms silyl, aryl or heteroaryl An aryl group or a linear, branched or cyclic alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy group having 1 to 20, preferably 1 to 12 C atoms, wherein One or more hydrogen atoms may be optionally substituted by F or Cl and the R ⁰ , R ⁰⁰ groups and X have the meanings described above for formula PB-1.

Particularly preferred repeating units of formula PB-1 selected from the group consisting of units of formulas PB-1F to PB-1I:

Where the symbols have the following meanings:
L is H, halogen, or an optionally fluorinated linear or branched alkyl or alkoxy group having 1 to 12 C atoms, preferably methyl, i-propyl, t-butyl. Represents n-pentoxy or trifluoromethyl;
L'is an optionally fluorinated linear or branched alkyl or alkoxy group having 1 to 12 C atoms, preferably representing n-octyl or n-octyloxy).

To carry out the present invention, polymers containing two or more of the structural elements of groups 1 to 7 above are preferred. Further, it may be provided that the polymer preferably contains two or more of the structural elements from one of the above groups, ie comprises a mixture of structural elements selected from one group.

In particular, in addition to the at least one structural element (group 4) having luminescent properties, preferably at least one phosphorescent group, at least one further structural element of the above groups 1-3, 5 or 6 is additionally added. Polymers containing are particularly preferred, where they are preferably selected from groups 1-3.

The proportions of the various classes of groups, if present in the polymer, can be within wide ranges, as these are known to the person skilled in the art. In each case, the proportion of one class present in the polymer selected from the structural elements of groups 1 to 7 above is preferably 5 mol% or more in each case, particularly preferably 10 mol% or more in each case. , Amazing benefits can be achieved.

The preparation of white-emitting copolymers is described in detail in DE 10343606A1, among others.

To improve solubility, the polymer may contain corresponding groups. Preferably, the polymer contains substituents such that on average at least 2 non-aromatic carbon atoms per repeating unit, particularly preferably at least 4 and particularly preferably at least 8 non-aromatic carbon atoms are present. It may be provided that the mean is related to the number mean. Here, individual carbon atoms may be replaced by, for example, O or S. However, it is also possible that a certain proportion, optionally all repeating units, do not contain substituents containing non-aromatic carbon atoms. Here, the long-chain substituent is preferable because the long-chain substituent may adversely affect the layer obtained by using the organic functional material. The substituents preferably contain not more than 12 carbon atoms in the straight chain, preferably not more than 8 carbon atoms and particularly preferably not more than 6 carbon atoms.

The polymers used according to the invention as organic functional materials can be random, alternating or regioregular copolymers, block copolymers, or a combination of these copolymer forms.

In a further aspect, the polymer used as the organic functional material can be a non-conjugated polymer with side chains, where this aspect is particularly important in the case of polymer-based phosphorescent OLEDs. In general, phosphorescent polymers can be obtained by free-radical copolymerization of vinyl compounds, wherein these vinyl compounds, as disclosed in inter alia US 7250226 B2, contain at least one unit having a phosphorescent emitter and And/or contains at least one charge transport unit. Further phosphorescent polymers are described, inter alia, in JP2007/2112443A2, JP2007/197574A2, US7250226B2 and JP2007/059939A.

In a further preferred embodiment, the non-conjugated polymer contains backbone units linked together by spacer units. Examples of such triplet emitters based on non-conjugated polymers based on backbone units are disclosed, for example, in DE 102009023154.

In a further preferred embodiment, the non-conjugated polymer can be designed as a fluorescent emitter. Preferred fluorescent emitters based on non-conjugated polymers with side chains contain anthracene or benzanthracene groups or derivatives of these groups in the side chains, where these polymers are for example JP2005/108556, JP2005/285661. And JP 2003/338375.

These polymers can often be used as electron or hole transport materials, where they are preferably designed as non-conjugated polymers.

Further, the functional compound used as an organic functional material in the preparation is preferably a polymer compound of 10,000 g/mol or more, particularly preferably 20,000 g/mol or more, particularly preferably 50,000 g/mol or more. With a molecular weight M _w of

The molecular weight M _w of the polymer here is preferably in the range from 10,000 to 2,000,000 g/mol, particularly preferably in the range from 20,000 to 1,000,000 g/mol, very particularly preferably 50, It is in the range of 000 to 300,000 g/mol. The molecular weight M _w is determined by GPC (=gel permeation chromatography) against internal polystyrene standards.

The publications cited above for the description of functional compounds are incorporated herein by reference for the purpose of disclosure.

The formulations according to the invention may comprise all the organic functional materials necessary for the production of the respective functional layers of the electronic device. For example, if the hole-transporting, hole-injecting, electron-transporting or electron-injecting layer is exactly built up from one functional compound, the formulation contains exactly this compound as an organic functional material. For example, if the emissive layer comprises a phosphor in combination with a matrix or host material, the formulation may comprise a mixture of phosphor and matrix or host material as the organic functional material, as described in more detail elsewhere herein. Exactly include.

In addition to the abovementioned components, the formulations according to the invention may comprise further additives and processing aids. These are, inter alia, surface-active substances (surfactants), lubricants and greases, viscosity-adjusting additives, conductivity-increasing additives, dispersants, hydrophobizing agents, adhesion promoters, flow improvers. , Defoamers, deaerators, diluents, which may be reactive or non-reactive, fillers, auxiliaries, processing aids, dyes, pigments, stabilizers, sensitizers, nanoparticles, and inhibitors including.

The invention further relates to a method for preparing a formulation according to the invention, wherein at least a first organic solvent containing at least one formic acid group and at least one organic solvent which can be used for the production of functional layers of electronic devices. Functional materials are mixed.

The formulations according to the invention can be used for the production of layers or multilayer structures in which the organic functional material is present in the layers as required for the production of preferred electronic or optoelectronic components, for example OLEDs.

The formulations of the invention can preferably be used to form a functional layer on a substrate or one of the layers applied to the substrate. The substrate may or may not have a bank structure.

The invention likewise relates to a method for producing an electronic device, in which a formulation according to the invention is applied to a substrate and dried.

The functional layer may be a substrate or substrate, for example by flood coating, dip coating, spray coating, spin coating, screen printing, letterpress printing, gravure printing, rotary printing, roller coating, flexographic printing, offset printing or nozzle printing, preferably inkjet printing. Can be produced on one of the layers applied to the.

After applying the formulation according to the invention onto the substrate or already applied functional layer, a drying step can be carried out in order to remove the solvent from the continuous phase. Drying can be carried out preferably at a relatively low temperature and for a relatively long time, in order to avoid bubble formation and obtain a uniform coating. Drying can be carried out at temperatures preferably in the range of 80-300°C, more preferably 150-250°C, most preferably 160-200°C. Here, the drying can be carried out at a pressure preferably in the range of 10 ⁻⁶ mbar to ² bar, more preferably in the range of 10 ⁻² mbar to ¹ bar, and most preferably in the range of 10 ⁻¹ mbar to 100 mbar. During the drying process, the temperature of the substrate can change from -15°C to 250°C. The drying time depends on the degree of drying to be achieved, in which case small amounts of water can optionally be removed at relatively high temperatures in combination with sintering, which should preferably be done.

It may be further defined that the process is repeated several times, with the formation of different or identical functional layers. Here, the functional layer thus formed can be crosslinked as disclosed in, for example, EP0637899A1 to prevent its decomposition.

The invention further relates to an electronic device obtainable by a method of manufacturing an electronic device.

The invention further relates to an electronic device having at least one functional layer comprising at least one organic functional material obtainable by the method of manufacturing an electronic device described above.

Electronic device is taken to mean a device comprising an anode, a cathode and at least one functional layer in between, which functional layer comprises at least one organic or organometallic compound.

The organic electronic device is preferably an organic electroluminescent device (OLED), a polymer electroluminescent device (PLED), an organic integrated circuit (O-IC), an organic field effect transistor (O-FET), an organic thin film transistor (O). -TFT), organic light emitting transistor (O-LET), organic solar cell (O-SC), organic photovoltaic (OPV) cell, organic optical detector, organic photoreceptor, organic electric field quenching device (O-FQD). , Organic electrosensors, light emitting electrochemical cells (LECs) or organic laser diodes (O-lasers), more preferably organic electroluminescent devices (OLEDs) or polymer electroluminescent devices (PLEDs).

Active ingredients are generally organic or inorganic materials that are introduced between the anode and the cathode, where these active ingredients achieve, maintain and/or achieve the properties of the electronic device, such as its performance and/or its lifetime. Or enhancers, such as charge injection, charge transport or charge blocking materials, but in particular luminescent materials and matrix materials. Therefore, the organic functional material that can be used for manufacturing the functional layer of the electronic device preferably contains the active component of the electronic device.

Organic electroluminescent devices are a preferred embodiment of the present invention. Organic electroluminescent devices include a cathode, an anode, and at least one emissive layer.

It is further preferred to use a mixture of two or more triplet emitters with the matrix. Here, the triplet emitter with a short wavelength emission spectrum functions as a co-matrix for the triplet emitter with a longer wavelength emission spectrum.

In this case, the ratio of the matrix material in the light emitting layer is preferably 50 to 99.9% by volume, more preferably 80 to 99.5% by volume, and most preferably 92 to 99.5% by volume in the case of the fluorescent light emitting layer. In the case of a phosphorescent light emitting layer, it is 85 to 97% by volume.

Correspondingly, the proportion of dopant is preferably 0.1 to 50% by volume, more preferably 0.5 to 20% by volume and most preferably 0.5 to 8% by volume in the case of a fluorescent emitting layer. In the case of a phosphorescent light emitting layer, it is 3 to 15% by volume.

The light emitting layer of the organic electroluminescent device may further include a system including a plurality of matrix materials (mixed matrix system) and/or a plurality of dopants. Again, the dopant is generally the material with the lower proportion in the system and the matrix material is the material with the higher proportion in the system. However, in individual cases, the proportion of the individual matrix materials in the system may be lower than the proportion of the individual dopants.

The mixed matrix system preferably comprises 2 or 3 different matrix materials, more preferably 2 different matrix materials. Here, preferably, one of the two materials is a material having a hole-transporting property, and the other material is a material having an electron-transporting property. However, the desired electron transporting and hole transporting properties of the mixed matrix component may be predominantly or completely combined in a single mixed matrix component, in which case the additional mixed matrix component(s) are Perform a function. Here, the two different matrix materials are 1:50 to 1:1, preferably 1:20 to 1:1, more preferably 1:10 to 1:1 and most preferably 1:4 to 1:1. May be present in the ratio of. Mixed matrix systems are preferably used in phosphorescent organic electroluminescent devices. Further details regarding mixed matrix systems can be found, for example, in WO 2010/108579.

Apart from these layers, the organic electroluminescent device comprises further layers, for example in each case one or more hole injection layers, hole transport layers, hole blocking layers, electron transport layers, electron injection layers, Exciton blocking layer, electron blocking layer, charge generation layer (IDMC 2003, Taiwan; Session 21 OLED (5), T. Matsumoto, T. Nakada, J. Endo, K. Mori, N. Kawamura, A. Yokoi, J. Kido, Multiphoton Organic EL Device Having Charging Generation Layer) and/or organic or inorganic p/n junctions. Here, one or more hole transport layers are p-doped, for example with a metal oxide, such as MoO ₃ or WO ₃ , or with a (per)fluorinated electron-deficient aromatic compound, and/or one or more The electron transport layer can be n-doped. It is likewise possible to introduce between the two emitting layers an intermediate layer which has, for example, an exciton blocking function and/or which controls the charge balance in an electroluminescent device. However, it should be pointed out that each of these layers does not necessarily have to be present. These layers may likewise be present in the use of the formulations according to the invention, as defined above.

In a further aspect of the invention, the device comprises multiple layers. Here, the formulations according to the invention can preferably be used for hole transporting, hole injecting, electron transporting, electron injecting and/or producing light-emitting layers.

Accordingly, the invention further comprises at least three layers of hole injection, hole transport, light emission, electron transport, electron injection, charge blocking and/or charge generating layers, and in a preferred embodiment all of said layers. , But at least one layer is obtained by the formulation to be used according to the invention. The thickness of the layer, eg the hole transport and/or hole injection layer, may preferably be in the range 1 to 500 nm, more preferably 2 to 200 nm.

The device may further comprise layers constructed from low molecular weight compounds or polymers, which have not been applied by the use of the formulations according to the invention. These can be produced by evaporation of low molecular weight compounds in high vacuum.

In addition, it may be preferable not to use the compounds to be used as pure substances, but instead as a mixture (blend) with further polymers, oligomers, dendritic or low molecular weight substances of any desired type. They may, for example, improve electronic properties and may themselves emit light.

In a preferred embodiment of the invention, the formulation according to the invention comprises an organic functional material used as host material or matrix material in the light-emitting layer. Here, the formulation may comprise, in addition to the host material or matrix material, the abovementioned phosphors. Here, the organic electroluminescent device may include one or more light emitting layers. When multiple emissive layers are present, they preferably have multiple emission maxima between 380 nm and 750 nm to give an overall white emission, ie various emissive compounds capable of emitting fluorescence or phosphorescence emit. Used for layers. A three-layer system is very particularly preferred, where the three layers exhibit blue, green, and orange or red emission (for basic structure see eg WO 2005/011013). White light emitting devices are suitable, for example, as backlighting for LCD displays or for general lighting applications.

It is also possible to arrange a plurality of OLEDs one above the other to allow a further increase in efficiency with regard to the light yield to be realized.

In order to improve the light coupling-out, the final organic layer on the light output side in the OLED can also be provided, for example in the form of nanofoams, to bring about a reduction in the proportion of total internal reflection.

Further preferred is an organic electroluminescent device in which one or more layers are applied by a sublimation process, wherein the material is less than 10 ⁻⁵ mbar, preferably less than 10 ⁻⁶ mbar, more preferably in a vacuum sublimation unit. Is applied by vapor deposition at a pressure of less than 10 ⁻⁷ mbar.

Furthermore, it may be provided that one or more layers of the electronic device according to the invention are applied by an OVPD (organic vapor deposition) process or by taking advantage of carrier gas sublimation, wherein the material is It is applied at a pressure of 10 ⁻⁵ mbar to 1 bar.

Furthermore, one or more layers of the electronic device according to the invention are from a solution, for example by spin coating, or by any desired printing process, such as screen printing, flexographic printing or offset printing, but particularly preferably LITI. It may be specified that it is manufactured by (photoinduced thermal imaging, thermal transfer printing) or inkjet printing.

These layers may be applied by methods in which no compound of formula (I), (II), (IIa), (III) or (IIIa) is used. Here, it is possible to preferably use an orthogonal solvent in which the functional material of the layer to be applied is soluble, but not the layer in which the functional material is applied.

Devices typically include a cathode and an anode (electrode). The electrodes (cathode, anode) are, for the purposes of the present invention, such that their band energies are as close as possible to the band energies of adjacent organic layers, in order to ensure highly efficient electron or hole injection. To be selected.

The cathode is preferably a metal complex, a metal with a low work function, a metal alloy or various metals such as alkaline earth metals, alkali metals, main group metals or lanthanides (eg Ca, Ba, Mg, Al, In, Mg). , Yb, Sm, etc.) and the like. In the case of multilayer structures, it is also possible to use further metals having a relatively high work function, such as Ag and Ag nanowires (AgNW), in addition to said metals, in which case a combination of metals, for example Ca/Ag or Ba/Ag. Are commonly used. It may also be preferable to introduce a thin intermediate layer of material with a high dielectric constant between the metallic cathode and the organic semiconductor. Suitable for this purpose are, for example, alkali metal or alkaline earth metal fluorides as well as the corresponding oxides (eg LiF, Li ₂ O, BaF ₂ , MgO, NaF, etc.). The layer thickness of this layer is preferably 0.1 to 10 nm, more preferably 0.2 to 8 nm, and most preferably 0.5 to 5 nm.

The anode preferably comprises a material having a high work function. The anode preferably has a potential above 4.5 eV against vacuum. Suitable for this purpose are on the one hand metals having a high redox potential, such as Ag, Pt or Au. On the other hand, metal/metal oxide electrodes (eg Al/Ni/NiO _x , Al/PtO _x ) may also be preferred. In some applications, at least one of the electrodes must be transparent in order to facilitate either organic material illumination (O-SC) or light coupling out (OLED/PLED, O-lasers). The preferred structure uses a transparent anode. Here, the preferred anode material is a conductive mixed metal oxide. Indium tin oxide (ITO) or indium zinc oxide (IZO) is especially preferred. Further preferred are conductive doped organic materials, especially conductive doped polymers such as poly(ethylenedioxythiophene) (PEDOT) and polyaniline (PANI), or derivatives of these polymers. It is further preferred that a p-doped hole-transporting material is applied to the anode as a hole-injection layer, where suitable p-dopants are metal oxides such as MoO ₃ or WO ₃ or (per)fluorinated electrons. It is a deficient aromatic compound. Further suitable p-dopants are HAT-CN (hexacyanohexaazatriphenylene) or the compound NPD9 from Novaled. This type of layer simplifies hole injection in materials with low HOMO, i.e. high values of HOMO.

In general, all the materials as used in the layers according to the prior art can be used in the further layers, and the person skilled in the art can combine each of these materials with the material according to the invention without inventive step in electronic devices. ..

Correspondingly, the devices are constructed in a manner known per se and, depending on the application, are provided with contacts and, in the presence of water and/or air, the lifespan of such devices can be significantly reduced, so that they are eventually sealed. To be done.

The formulations according to the invention and the electronic devices obtainable therefrom, in particular organic electroluminescent devices, are distinguished from the prior art by one or more of the following surprising advantages:
1. The electronic devices obtainable with the formulations according to the invention exhibit very high stability and a very long lifetime compared to electronic devices obtainable using conventional methods.
2. The formulations according to the invention can be processed using conventional methods, so that a cost advantage can be realized.
3. The organic functional materials used in the formulations according to the invention allow the method of the invention to be used comprehensively without any particular restrictions.
4. The coatings obtainable with the formulations according to the invention exhibit excellent qualities, especially with regard to coating uniformity.

These above advantages do not come with the loss of other electronic properties.

It should be pointed out that variations of the embodiments described in the present invention are included within the scope of the present invention. Each feature disclosed in this invention can be replaced by an alternative feature serving the same, equivalent or similar purpose, unless explicitly excluded. Therefore, each feature disclosed in the present invention should be considered as an example of a comprehensive series, or equivalent or similar features, unless otherwise specified.

All the features of the invention can be combined with one another in any way, unless the particular features and/or steps are mutually exclusive. This applies in particular to the preferred features of the invention. Similarly, non-essential combination features can be used individually (and without combination).

It should be further pointed out that many features, especially those of the preferred embodiments of the invention, are inventive in their own right and should not be regarded as only part of an embodiment of the invention. Independent protection may be sought for these features in addition to, or as an alternative to, each invention claimed in the present invention.

The teachings about the technical acts disclosed by the present invention can be extracted and combined with other examples.

The invention is explained in more detail below with reference to examples, without being limited thereby.

A person skilled in the art can use this description to manufacture further electronic devices according to the invention without the need to use creative techniques, and thus to practice the invention throughout the claimed scope.

FIG. 1 shows a substrate, an ITO anode, a hole injection layer (HIL), a hole transport layer (HTL), a green light emitting layer (G-EML), a hole blocking layer (HBL), an electron transport layer (ETL) and Al. 1 shows a typical layer structure of a device containing a cathode.

[Example]
The example presented below was made using the device structure shown in FIG. The hole injection layer (HIL) and hole transport layer (HTL) of all examples were prepared by inkjet printing to achieve the desired thickness. For the light emitting layer, the individual solvents used in Examples 1-3 are listed in Table 2 below:

Formulation and solvent viscosities were measured using a TA instruments ARG2 rheometer using a 40 mm parallel plate structure over a shear rate range of 10-1000 s- ¹ . The measured value was used as an average of 200 to 800 s ⁻¹ in which the temperature and the shear rate were accurately controlled. The viscosities shown in Table 3 are the viscosities of each formulation measured at a temperature of 25°C. Each solvent is measured 3 times. The viscosity values listed are the average of the above measurements.

Preferably, the organic solvent blend may comprise a surface tension in the range 15-80 mN/m, more preferably in the range 20-60 mN/m, most preferably in the range 25-40 mN/m. The surface tension can be measured at 20° C. using an FTA (First Ten Angstrom) 1000 contact angle goniometer. Details of the method are described in Roger P. et al. Woodward, Ph. D. Available from First Ten Angstrom, as announced by "Surface Tension Measurements Using the Drop Shape Method". Preferably, the pendant drop method can be used to determine the surface tension. All measurements were performed at room temperature, which ranged from 20°C to 22°C. Three drops are measured for each formulation. The final value is an average of the measured values. The tool is regularly cross-checked against various liquids with known surface tension.

Examples 1-3 are made by using the same structure where HIL and HTL are inkjet printed to achieve the same thickness. The solvent(s) used in the EML are different and details are listed in Table 3.

Description of Method of Preparation A glass substrate coated with pre-structured ITO and bank material is cleaned using sonication in isopropanol followed by deionized water, then dried using an air gun, followed by a hot plate. Annealed at 230° C. for 2 hours above.

A hole injection layer (HIL) using PEDOT-PSS (Clevios Al4083, Heraeus) was inkjet printed onto the substrate and dried in vacuum. The HIL was then annealed in air at 185°C for 30 minutes.

The hole transport layer (HTL) was inkjet printed onto the HIL, dried in vacuum and annealed at 210° C. for 30 minutes in a nitrogen atmosphere. Polymer HTM-1 was used as the material for the hole transport layer. The structure of polymer HTM-1 is as follows:

The green light emitting layer (G-EML) was similarly inkjet printed, vacuum dried, and annealed at 160° C. for 10 minutes in a nitrogen atmosphere. In all examples, the ink for the green emitting layer contained two host materials (i.e. HM-1 and HM-2) and one triplet emitter (EM-1). The materials were used in the following ratio: HM-1:HM-2:EM-1=40:40:20. As can be seen from Table 3, only the solvent(s) differ from example to example. The structures of these materials are as follows:

All inkjet printing processes were performed under ambient conditions under yellow light.

The device was then transferred to a vacuum deposition chamber where thermal evaporation was used to deposit the hole blocking layer (HBL), electron transport layer (ETL), and cathode (Al). The device was then characterized in the glove box.

ETM-1 was used as the hole blocking material for the hole blocking layer. This material has the following structure:

A 50:50 mixture of ETM-1 and LiQ was used for the electron transport layer (ETL). LiQ is lithium 8-hydroxyquinolinate.

To measure OLED performance in current density-brightness-voltage performance, the device is driven by a sweep voltage of -5V to 25V supplied by a Keithley 2400 source measurement unit. The voltage across the OLED device and the current through the OLED device is recorded by the Keithley 2400SMU. The device brightness is detected by a calibrated photodiode. Photocurrent is measured by a Keithley 6485/E picoammeter. For the spectrum, the luminance sensor has been replaced by a glass fiber connected to an Ocean Optics USB2000+ spectrometer.
Results and discussion Example 1
Inkjet printed OLED devices are prepared with the printed layer using geranyl formate as the solvent for the light emitting layer. The structure of the pixelated OLED device is glass/ITO/HIL(40nm)/HTM(20nm)/EML(60nm)/HBL(10nm)/ETL(40nm)/Al, which allows the bank to be pre-formed on the substrate. Created to form a pixellated device. In this case, the green luminescent material was dissolved in geranyl formate at a concentration of 22 mg/ml.

The luminance efficiency at 1000 cd/m ² is 46.69 cd/A. The efficiency of this OLED device is very good, the voltage at 1000 cd/m ² is 7.2V.

Example 2
An inkjet printed OLED device is prepared with the printed layer using terpinyl formate as the solvent for the light emitting layer. The structure of the pixelated OLED device is glass/ITO/HIL(40nm)/HTM(20nm)/EML(60nm)/HBL(10nm)/ETL(40nm)/Al, which allows the bank to be pre-formed on the substrate. Created to form a pixellated device. In this case, the green emitting material was dissolved in terpinyl formate at a concentration of 16 mg/ml.

At L=1000 cd/m ² , the luminance efficiency is 46.25 cd/A. The efficiency of this OLED device shows a good value, the voltage at 1000 cd/m ² is 6.38V.

Example 3
Inkjet printed OLED devices are prepared with the printed layer using linalyl formate as the solvent for the light emitting layer. The structure of the pixelated OLED device is glass/ITO/HIL(40nm)/HTM(20nm)/EML(60nm)/HBL(10nm)/ETL(40nm)/Al, which allows the bank to be pre-formed on the substrate. Created to form a pixelated device. In this case, the green luminescent material was dissolved in linalyl formate at a concentration of 17 mg/ml.

At L=1000 cd/m ² , the luminance efficiency is 38.03 cd/A. The efficiency of this OLED device shows a good value, the voltage at 1000 cd/m ² is 6.36V.

Changes in formulation composition can have various advantages in creating a wide range of formulations with different physical properties that can improve the process window.

The measurements for all examples are summarized in Table 4 below.

Claims (22)

A formulation containing at least one organic functional material and at least a first organic solvent, said first organic solvent containing at least one formic acid group, preferably one formic acid group. Stuff. The first organic solvent containing one formic acid group has the general formula (I)
(In the formula,
R is
-H, F,
-A linear alkyl group having 1 to 20 carbon atoms, a linear alkenyl group having 2 to 20 carbon atoms, or a branched alkyl or alkenyl group having 3 to 20 carbon atoms (wherein 1 One or more non-adjacent CH ₂ groups are —O—, —S—, —NR ¹ —, —CONR ¹ —, —CO—O—, —C═O—, —CH═CH— or —C. ≡ C-, optionally one or more hydrogen atoms may be replaced by F), or-optionally substituted by one or more non-aromatic R ¹ radicals, 6 A cyclic alkyl or alkenyl group having 20 to 20 carbon atoms or an aryl or heteroaryl group having 4 to 14 carbon atoms, wherein the plurality of substituents R ¹ are either on the same ring or on two different rings. And may together form a monocyclic or polycyclic aliphatic or aromatic ring system optionally substituted by a plurality of substituents R ¹ .
R ¹ is the same or different in each case and is a straight-chain alkyl or alkoxy group having 1 to 20 carbon atoms or a branched or cyclic alkyl or alkoxy group having 3 to 20 carbon atoms (here And one or more non-adjacent CH ₂ groups are replaced by —O—, —S—, —CO—O—, —C═O—, —CH═CH— or —C≡C—. Optionally one or more hydrogen atoms may be replaced by F), or having from 4 to 14 carbon atoms and optionally substituted by one or more non-aromatic R ¹ radicals. A good aryl or heteroaryl group;
X is a linear alkyl group having 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms, 2 to 10 linear chain alkenyl groups having 2 to 5 carbon atoms, or 3 to 10 carbon atoms; Preferred is a branched alkyl or alkenyl group having 3 to 5 carbon atoms;
n is 0 or 1)
A formulation according to claim 1, which is a solvent containing a formic acid group according to. The first organic solvent containing one formic acid group has the general formula (I)
(In the formula,
R is an aryl or heteroaryl group having 4 to 14 carbon atoms, which may be substituted by one or more non-aromatic R ¹ radicals, the plurality of substituents R ¹ are on the same ring or Either on two different rings may together form a mono- or polycyclic aliphatic or aromatic ring system optionally substituted by a plurality of substituents R ¹ .
R ¹ is the same or different in each case and is a straight-chain alkyl or alkoxy group having 1 to 20 carbon atoms or a branched or cyclic alkyl or alkoxy group having 3 to 20 carbon atoms (here And one or more non-adjacent CH ₂ groups are replaced by —O—, —S—, —CO—O—, —C═O—, —CH═CH— or —C≡C—. Optionally one or more hydrogen atoms may be replaced by F), or having from 4 to 14 carbon atoms and optionally substituted by one or more non-aromatic R ¹ radicals. A good aryl or heteroaryl group;
X is a linear alkyl group having 1 to 5 carbon atoms, a linear alkenyl group having 2 to 5 carbon atoms or a branched alkyl or alkenyl group having 3 to 5 carbon atoms;
n is 0 or 1)
A formulation according to claim 1 or 2 which is a solvent containing formic acid groups according to. The first organic solvent containing one formic acid group has the general formula (I)
(In the formula,
R is a cyclic alkyl or alkenyl group having 6 to 20 carbon atoms, which may be substituted by one or more non-aromatic R ¹ radicals, and multiple substituents R ¹ are on the same ring or Either on two different rings may together form a mono- or polycyclic aliphatic or aromatic ring system optionally substituted by a plurality of substituents R ¹ .
R ¹ is the same or different in each case and is a straight-chain alkyl or alkoxy group having 1 to 20 carbon atoms or a branched or cyclic alkyl or alkoxy group having 3 to 20 carbon atoms (here And one or more non-adjacent CH ₂ groups are replaced by —O—, —S—, —CO—O—, —C═O—, —CH═CH— or —C≡C—. Optionally one or more hydrogen atoms may be replaced by F), or having from 4 to 14 carbon atoms and optionally substituted by one or more non-aromatic R ¹ radicals. A good aryl or heteroaryl group;
X is a linear alkyl group having 1 to 5 carbon atoms, a linear alkenyl group having 2 to 5 carbon atoms or a branched alkyl or alkenyl group having 3 to 5 carbon atoms;
n is 0 or 1)
A formulation according to claim 1 or 2 which is a solvent containing formic acid groups according to. The first organic solvent containing one formic acid group has the general formula (III)
(In the formula,
R is a straight chain alkyl group having 1 to 20 carbon atoms, a straight chain alkenyl group having 2 to 20 carbon atoms, or a branched alkyl or alkenyl group having 3 to 20 carbon atoms (wherein The one or more non-adjacent CH ₂ groups are —O—, —S—, —NR ¹ —, —CONR ¹ —, —CO—O—, —C═O—, —CH═CH— or —C≡C—, optionally one or more hydrogen atoms may be replaced by F);
R ¹ is the same or different in each case and is a straight-chain alkyl or alkoxy group having 1 to 20 carbon atoms or a branched or cyclic alkyl or alkoxy group having 3 to 20 carbon atoms (here And one or more non-adjacent CH ₂ groups are replaced by —O—, —S—, —CO—O—, —C═O—, —CH═CH— or —C≡C—. Or one or more hydrogen atoms may be replaced by F)).
A formulation according to claim 1 or 2 which is a solvent containing formic acid groups according to. The formulation according to any one of claims 1 to 5, wherein the first solvent has a surface tension of 20 mN/m or more. The formulation according to any one of claims 1 to 6, wherein the content of the first solvent is in the range of 50 to 100 vol% based on the total amount of the solvents in the formulation. The formulation according to any one of claims 1 to 7, wherein the first solvent has a boiling point in the range of 100 to 400°C. 9. The formulation according to any one of claims 1-8, wherein the formulation comprises at least one second solvent different from the first solvent. The formulation according to any one of claims 1 to 9, wherein the second solvent has a boiling point in the range of 100 to 400°C. The formulation according to any one of claims 1 to 10, wherein the at least one organic functional material has a solubility in the first and second solvents in the range of 1 to 250 g/l. The formulation according to any one of claims 1 to 11, wherein the formulation has a surface tension in the range of 10 to 50 mN/m. The formulation according to any one of claims 1 to 12, wherein the formulation has a viscosity in the range of 1 to 50 mPa·s. The content of the at least one organic functional material in the formulation is in the range of 0.001 to 20 wt% based on the total weight of the formulation. The formulation as described. The at least one organic functional material is an organic conductor, an organic semiconductor, an organic fluorescent compound, an organic phosphorescent compound, an organic light absorbing compound, an organic photosensitive compound, an organic photosensitizer, and another organic photoactive compound, Formulation according to any one of claims 1 to 14, for example selected from the group consisting of organometallic complexes of transition metals, rare earths, lanthanides and actinides. The at least one organic functional material is a fluorescent emitter, phosphorescent emitter, host material, matrix material, exciton blocking material, electron transport material, electron injection material, hole conduction material, hole injection material, n-dopant. 16. The formulation of claim 15, selected from the group consisting of:, p-dopants, wide bandgap materials, electron blocking materials, and hole blocking materials. The formulation according to claim 15, wherein the at least one organic functional material is an organic semiconductor selected from the group consisting of hole injection, hole transport, light emission, electron transport and electron injection materials. 18. The formulation of claim 17, wherein the at least one organic semiconductor is selected from the group consisting of hole injection and hole transport materials. 19. The formulation of claim 18, wherein the hole injection and hole transport material is a polymeric compound or a blend of polymeric and non-polymeric compounds. 20. A method of preparing a formulation according to any one of claims 1-19, wherein the at least one organic functional material and the at least first solvent are mixed. An electroluminescent device, wherein at least one layer of an electroluminescent device is prepared by depositing a formulation according to any one of claims 1 to 19 on a surface, preferably printing and subsequent drying. How to prepare a cent device. An electroluminescent device, wherein at least one layer is prepared by depositing the formulation according to any one of claims 1 to 19 on a surface, preferably printing and subsequent drying.