HK1148609A - Organic semiconductor formulation - Google Patents

Description

Organic semiconductor composition

Technical Field

The present invention relates to a process for the preparation of compositions comprising an Organic Semiconductor (OSC) and one or more organic solvents, to novel compositions obtained by this process, and to their use as coatings or printing inks for the preparation of Organic Electronic (OE) devices, especially Organic Field Effect Transistors (OFETs) and Organic Photovoltaic (OPV) cells, as well as to a process for the preparation of OE devices using the novel compositions, and to OE devices prepared from such a process or from the novel compositions.

Background

When preparing OE devices, such as OFETs or OPV cells, or organic light emitting devices, such as Organic Light Emitting Diodes (OLEDs), in particular flexible devices, the OSC material layer is typically applied using coating or printing techniques. Printing compositions that have hitherto been used in the prior art for the preparation of OE devices are generally solution-based, comprise aromatic or aliphatic organic solvents and tend to have a low viscosity. Although this method is well suited for spin-and ink-jet printing (IJP) fabrication methods, there has recently been growing interest in fabricating devices using conventional printing techniques such as flexographic (flexographic) or gravure printing. This requires different types of compositions, in particular with regard to the choice of solvent and optional additives such as viscosity modifiers.

Many printing processes use compositions with moderate viscosity (typically from 10 to 1000cP), including inks for flexographic and gravure printing, but also inks for thermal spray IJP, electrostatic IJP, soft lithography and its variants or micro-stamping. However, there are some limitations to effectively printing OSC materials.

Thus, there is a need to obtain the right fluid properties for printing by a single solvent or a combination of mixed volatile solvents and functional materials alone, or with minimal addition of additional viscosity modifiers or binders. This generally results in a composition having a viscosity of < 10cP, for example from a tetrahydronaphthalene or xylene solution or the like. Flexographic and gravure printing generally require viscosities of > 10cP to achieve good print quality, and compositions with viscosities in the range of 25-100cP or even up to 5000cP are often employed.

Solutions of the active substance are generally preferred. For example, due to the hydrophilic nature of typical OSC materials under study, high viscosity polyols having viscosities within the above-mentioned ranges do not dissolve or are not compatible with these materials. In addition, they are often incompatible with the substrate and other components of the manufacturing process.

However, usual viscosity modifiers (e.g. inorganic substances such as silica, clay, etc., or very high M) which increase useful viscosity up to > 10cP_wPolymer, polymeric alcohol, etc.) on the other hand tend to deteriorate the performance of the OE device. In addition, silica, as well as clays, can negatively impact low shear flow, making the ink unsuitable for IJ, gravure, and flexographic printing.

Low viscosities (< 10cP) are often required, for example for spin coating and standard IJP techniques, while high viscosities (> 1000cP) are often required, for example for screen printing, lithography, etc.

US 6,541,300 discloses a method for preparing OSC thin films for OE devices by mixing the OSC material with a multi-component solvent mixture and applying the resulting mixture to a substrate. The OSC films obtained by using solvent mixtures are said to have higher flow and the resulting OE devices have higher on/off (on/off) ratios than OSC films or OE devices comprising OSC films, which are prepared using only one solvent of the multi-component solvent mixture. However, the claimed process is only characterized by the desired result, i.e. higher flowability and higher on/off ratio, and not by the means of how this result can be achieved. In particular, this document does not provide explicit guidance to the skilled person how to select a suitable solvent to obtain a composition that can be used. The document merely mentions that the solvents of the solvent mixture have a combined polarity (phi) of from 0.1 to 1.0_m) Wherein the combined polarity is represented by the formula:

n is the number of solvents, phi_iIs polar, and x_iIs the mole fraction of a single solvent in the solvent mixture. However, apart from this parameter, the document does not provide any limitation or guidance regarding the selection of OSC compounds and the selection of solvents that are most suitable for the selected OSC compounds. Although this document discloses a series of OSC compounds (including polymers and small molecules) and a series of solvents with a polarity from low to high values, it is not clear whether all these solvents will readily dissolve the disclosed OSC compounds. However, it is known that when the solvent does not dissolve the OSC material, the resulting mixture is often not suitable for the preparation of OSC films and OE devices, since the morphology of the resulting OSC film will deteriorate, which will negatively affect the performance of the OE device. Thus, in view of the teaching of US 6,541,300, considerable effort is still required to find a solvent suitable for a given OSC material as disclosed in this document.

WO 03/069959a1 discloses an OSC thin film for an Electroluminescent (EL) device, which is formed by a wet film method using a composite solution. The composite solution is prepared by dissolving at least two organic compounds into a mixed organic solvent including at least two organic solvents having different volatilities and different dissolving capacities for the organic compounds. Furthermore, this document discloses a large series of possible solvents and organic compounds, but does not provide explicit teaching as to how a suitable solvent can be selected for a given organic compound. Rather, it is merely said that the choice of at least two organic solvents having different volatilities may depend on the nature of the organic compound.

EP 1416069 a1 discloses OSC elements which comprise polyacenes as OSC materials. The document further mentions that the polyacene is soluble in a solvent, and that a combination of two or more solvents may be used. However, no particular solvent or combination of solvents is preferred other than the series of standard solvents, and no specific guidance is provided as to the selection of a suitable solvent.

WO 2005/041322 a1 discloses an organic polymer solution for use in an OE device, comprising at least one organic polymer, a first solvent and a second solvent, wherein the first solvent has a low dissolving capacity and a faster evaporation rate than the second solvent, and the second solvent has a very low dissolving capacity. Also claimed is a method of manufacturing an OE device by depositing the solution onto an electrode and allowing it to dry. It is stated that due to the different dissolving power and evaporation rate of the solvents, a substantially uniform polymer layer is formed. However, no specific values or parameter ranges are given for solvent properties that can be used as a basis for selecting a suitable solvent.

EP 1122793 a2 discloses organic light emitting devices made from inks comprising an organic EL material and a hydrophobic organic solvent or solvent mixture, wherein these solvents have a water solubility of at most 5 wt.% at room temperature. However, this value applies to virtually all OLED solvents known in the art and therefore does not constitute a practical limitation. It is further mentioned that the ink should have a viscosity of at most 5000cP, preferably at most 100 cP. However, there is no guidance as to how to select a particular solvent to achieve these values. This makes the selection of suitable solvents still difficult, especially when trying to prepare dilute small molecule solutions with high viscosity without the use of non-volatile thickeners.

WO 03/053707 a2 discloses a screen printable EL polymer ink comprising a soluble EL material, an organic solvent having a boiling point between 120 and 200 ℃ and a viscosity modifier which maintains a viscosity above 50 cP. The organic solvent should preferably have a composition of between 8.8 and 10.0 (cal/cm)³)^1/2Solubility parameter in between. Most of the viscosity modifiers mentioned in this document are polymeric or inorganic particles acting as "retarders" (which may also be commercially available products) at concentrations from 1to 20% to reduce solvent evaporation and to improve ink stability and processability. However, the use of the processing aids suggested in this document is not always desirable in OSC printing inks for the preparation of OE devices, since these processing aids are in addition toWill remain in the OSC layer after desolvation, where they may negatively affect or even impair the properties of the device. Instead, it is more preferred that only the pure active OSC material remains in the OSC layer after drying, without any processing aids. Thus, the ink preferably contains only volatile components in addition to the active OSC material.

Thus, there is still a need for methods that provide improved compositions and inks suitable for use in the manufacture of OSC materials for OE devices, in particular OFETs and OPV cells, wherein the methods allow a wide but precise selection of solvents that have a suitable viscosity and do not negatively affect the performance and lifetime of the device. It is an object of the present invention to provide such a method. Another object is to provide improved OSC compositions obtainable by such processes. It is a further object to provide improved OE devices obtainable from such OSC compositions. Other objects will be apparent to those skilled in the art from the following description.

The inventors of the present invention have found that these objects can be achieved by the presently claimed method of providing an OSC composition, and that the above problems can be solved. In particular, the inventors of the present invention have found a method of preparing an OSC composition by selecting an appropriate solvent or solvent mixture according to the distribution ratio (log P) and other parameters such as viscosity and boiling point. It was found that by appropriate selection of a solvent within a specific range of these parameters, an improved OSC composition can be provided, wherein the solvent dissolves the OE compound at useful levels and still has a viscosity suitable for the desired printing or coating technique. Since the parameters are defined for pure solvents, i.e. without any non-volatile additives, it is easier for the skilled person to select suitable solvents and additives, and to select suitable solvents and prepare the OSC coating or printing ink, without the need to use e.g. thickeners to adjust the viscosity. Coatings or printing inks prepared from these solvents can also be diluted with lower viscosity solvents to adjust the desired viscosity, if desired. Although the use of viscosity enhancing or modifying additives is not necessarily required, they may be added in small amounts that do not adversely affect the performance of the device.

Summary of The Invention

The present invention relates to a process for preparing an OSC composition, comprising the step of dissolving an Organic Semiconducting (OSC) compound into a solvent or a solvent mixture comprising two or more solvents, wherein the solvents are selected such that they fulfill the following conditions:

without any additives, the distribution ratio log P of the solvent, or the weighted average distribution ratio (log P) of the solvent mixture_w＞1.5，

The viscosity of the solvent or solvent mixture without any additives is > 10cP at 25 ℃, and

the boiling temperature of the solvent without any additives or, in the case of a solvent mixture, the boiling temperature of the highest boiling solvent of the solvent mixture is < 400 ℃ at a pressure of 1 Torr.

The invention further relates to a composition obtainable or obtained by the method.

The invention further relates to a composition comprising an OSC compound and an organic solvent or a solvent mixture of two or more organic solvents, characterized in that:

without any additives, the distribution ratio log P of the solvent, or the weighted average distribution ratio (log P) of the solvent mixture_w> 1.5, the viscosity of the solvent or solvent mixture is > 10cP at 25 ℃ without any additives, and

the boiling temperature of the solvent or solvent mixture without any additives is < 400 ℃ at a pressure of 1 Torr.

The invention further relates to the use of a composition as described above and below as a coating or printing ink and/or for the preparation of OE devices, in particular OFETs and OPV cartridges, very preferably for these types of flexible devices.

The invention further relates to a method of preparing an Organic Electronic (OE) device, comprising the steps of

a) Depositing a composition as described above and below onto a substrate,

b) the solvent(s) is removed, for example by evaporation.

The invention further relates to OE devices prepared from the compositions and/or methods described above and below.

OE devices include, but are not limited to, Organic Field Effect Transistors (OFETs), Integrated Circuits (ICs), Thin Film Transistors (TFTs), Radio Frequency Identification (RFID) tags, Organic Light Emitting Diodes (OLEDs), Organic Light Emitting Transistors (OLETs), electroluminescent displays, Organic Photovoltaic (OPV) cells, organic solar cells (O-SCs), flexible OPVs and O-SCs, organic laser diodes (O-lasers), organic integrated circuits (O-ICs), lighting devices, photosensitive devices, electrode materials, photoconductors, photodetectors, electrophotographic recording devices, capacitors, charge injection layers, schottky diodes, planarization layers, antistatic films, conductive substrates, conductive patterns (coupling patterns), photoconductors, electrophotographic devices, organic memory devices, biosensors, and biochips.

Brief description of the drawings

Fig. 1 schematically depicts the structure of a bottom gate OFET according to the present invention.

Fig. 2 schematically and generally depicts the structure of a top gate OFET according to the present invention.

Fig. 3 schematically generally depicts the structure of an OPV device according to the present invention.

Fig. 4 schematically generally depicts the structure of a conversion OPV device according to the present invention.

Fig. 5 shows the performance of the OFET device according to example 2.

Terms and definitions

As used herein, the plural forms of terms shall be construed to include the singular forms thereof and vice versa, unless the context clearly dictates otherwise.

Throughout the description and claims of this application, the words "comprise" and "include" and variations of the words, for example "comprising" and "comprises", mean "including but not limited to", but are not intended to (and do not) exclude other components.

The term "polymer" includes homopolymers and copolymers, such as statistical, alternating or block copolymers. Furthermore, the term "polymer" as used hereinafter also includes dendrimers, which are typically branched macromolecular compounds consisting of a multifunctional core group onto which branching monomers are further adducted in a regular manner to provide a tree-like structure, as described, for example, in m.Angew.chem., int.ed.1999, 38, 885.

The term "conjugated polymer" means a polymer mainly comprising sp in its skeleton (or main chain)²-a hybridized or optionally sp-hybridized C atom, which may also be replaced by a heteroatom, so that one pi-orbital can interact with another through an inserted sigma-bond. In the simplest case, this is, for example, a backbone with alternating carbon-carbon (or carbon-heteroatom) single and multiple (e.g. double or triple) bonds, but also polymers with units such as 1, 3-phenylene. In this connection, "predominantly" means that polymers having naturally (spontaneously) occurring defects which may lead to interruptions in conjugation are still considered to be conjugated polymers. This also includes those in which the skeleton contains, for example, units such as arylamines, arylphosphines and/or certain heterocycles (i.e.byConjugated with N-, O-, P-, or S-atoms) and/or organometallic complexes (i.e., conjugated via metal atoms). The term "conjugated linking group" refers to a group that links two moieties having an sp²-a group of hybridized or sp-hybridized C atoms or heteroatoms constituting a ring (generally an aromatic ring). See also "IUPAC Complex of Chemical research, electronic edition".

Molecular weight is taken as number average molecular weight M unless otherwise stated_nOr a weight average molecular weight M_wGiven, they are determined by Gel Permeation Chromatography (GPC) against polystyrene standards, unless otherwise indicated.

The polymerization degree (n) is a number average polymerization degree, and n is M_n/M_UIs given, unless otherwise stated, in which M_UIs the molecular weight of the individual repeat units.

The term "small molecule" refers to a monomeric, i.e., non-polymeric, compound.

Unless otherwise indicated, percentages of solids are weight percentages ("wt.%), percentages or proportions of liquids (e.g., in a solvent mixture) are volume percentages (" vol.%), and all temperatures are given in degrees celsius (° c), "Room Temperature (RT)" refers to 25 ℃, and "b.p." refers to boiling point, and "atmospheric pressure" refers to 760Torr or 1013 hPa.

The term "volatile" refers to compounds or additives that can be removed from the OSC material by evaporation after the OSC material has been deposited onto a substrate or OE device, under conditions (such as temperature and/or reduced pressure) that do not significantly damage the OSC or OE device. Preferably this means that the additive has a boiling or sublimation temperature of < 300 ℃, more preferably < 135 ℃, most preferably < 120 ℃ at the pressure used, very preferably at atmospheric pressure (1013 hPa). The term "non-volatile" refers to compounds or additives that are not volatile in the sense described above.

The partition ratio log P (also referred to as "partition coefficient" in the literature) of a compound or solvent is given by equation (1)

log P＝log([A]_oct/[A]_aq) (1)

Wherein [ A ] is]_octIs the concentration of the compound or solvent in octanol and [ A]_aqIs the concentration of the compound or solvent in water.

(see IUPAC Complex of Chemical technology, electronic edition,http://goldbook.iupac.org/P04440.html，PAC 1993，65，2385，and C.Hansch，Acc.Chem.Res.2，232，(1969))。

in the case of a solvent mixture comprising two or more solvents, the partition ratio of the mixture is defined as the weighted average (log P) of the partition ratios of all solvents contained in the mixture_wAs given by equation (2)

n is the number of solvents, log P_iIs the log P value of a single solvent in the solvent mixture, and w_iIs the weight fraction of the solvent in the solvent mixture (concentration in% w/100).

Log P values were determined by measuring the concentration in each phase after equilibration of the diluted solution in equal volumes of water and octanol (e.g., by GC, HPLC, UV/vis, etc.), or logP was calculated by molecular calculations using "Chem Bio Draw Ultra version 11.0 (2007)" software manufactured and sold by Cambridge Soft. unless otherwise noted.

Viscosity number of 500s^-1At shear rate of (2) using a parallel plate rotational viscometer or rheometer (TA Instrum)Nts) unless otherwise indicated.

Surface tension values were measured by spot shape analysis using an FTA surface tension instrument, unless otherwise noted.

Unless otherwise indicated, all physical properties and values above and below apply to a temperature of 25 ℃.

Detailed description of the invention

The process according to the invention allows to determine specific solvents and solvent mixtures, which are preferably selected from organic solvents which both dissolve the OSC compounds at useful levels and have a viscosity in the range suitable for printing processes, preferably in the range from 10 to 700cP, more preferably from 10 to 630cP at room temperature (25 ℃).

Inks made from these solvents can be subsequently diluted with low viscosity solvents if desired to adjust the viscosity as desired, provided the viscosity of the entire solvent mixture is > 10 cP.

The key parameters of the composition are as follows:

-the solvent or solvent mixture has a viscosity of > 10cP at 25 ℃ without any additives, and

-the solvent, or in the case of a solvent mixture the highest boiling point solvent of the solvent mixture, has a boiling point of < 400 ℃ at 1Torr, and

logarithmic value of the distribution ratio log P of the solvent or weighted average distribution ratio (log P) of the solvent mixture_wTo > 1.5, calculated according to the software "Chem Bio Draw Ultra version 11.0 (2007)" manufactured and sold by Cambridge soft, and

the OSC compound is preferably dissolved in a solvent or solvent mixture at a concentration of 0.005 to 50 wt.%.

To improve the properties of the composition, one or more of the following additives are optionally added:

a) one or more viscosity modifiers, preferably in a concentration such that they do not adversely affect device performance,

b) one or more surfactants selected from the group consisting of,

c) one or more polymers that adjust the physical properties, electrical properties, or stability of the printed composition.

The concentration of the viscosity modifier a) is preferably 0.001 to 200 wt.%, relative to the amount of OSC compound. One or more polymers are preferably added as viscosity modifiers to further increase the viscosity. Suitable and preferred polymers are selected from organic solvent soluble polymers, e.g. low M_wPolyethylene, low M_wHomopolymers or copolymers of polypropylene, other hydrocarbon-based polymers, polybutadiene, polyethylene and propylene oxide, polystyrene, alpha-methyl polystyrene, a associative thickener, SeptonPolymers such as Septon4099 (available from Kuraray America inc.), polytriarylamines or polymers disclosed for use as binders in US2007/0102696 a 1.

The concentration of the surfactant b) is preferably from 0.001 to 1.0 wt.%, very preferably from 0.05 to 0.5 wt.%, relative to the total composition. The main goal of these surfactants is to reduce the surface energy of the solution to enable improved wetting. Suitable and preferred surfactants include, but are not limited to, those selected from the group consisting of: fluorocarbons, fluorine-modified products, silicone-based products, acetylenic diols and polyacrylates, or other products such as alcohol alkoxylates. Many of these surfactants are commercially available, for example under the brand name "Fluor"(from Cytonics)," Zonyl "" (from Cytonics)"(from Dow)," Byk"(from Byk Chemie/Altana)," Tego"(from Tego/Evonik) or" Surfynol"(from Air Products). Examples of fluorocarbon surfactants include, but are not limited to, Fluor N361 or 362, Zonyl FSG (a fluorinated methacrylate polymer), Zonyl FSN100 (ethoxylated nonionic fluorosurfactants), and the like. Examples of fluorine-modified surfactants are Byk 388 (a fluorine-modified polyacrylate), Byk 340 (a polymeric fluorine surfactant), and the like. Examples of silicone-based surfactants include, but are not limited to, Tego Wet 270 (a polyether siloxane copolymer), Tego Wet KL245 (polyether siloxane copolymer), Tego Twin 4000 (silicone-based Gemini surfactant), Byk 307 (a polyether-modified dimethicone copolymer), Byk 310 (polyester-modified dimethicone), Byk 331 (polyether-modified dimethicone copolymer), and the like. Examples of acetylenic diols include, but are not limited to, Surfynol 104 and the like. Examples of polyacrylate surfactants include, but are not limited to, Byk 361N and the like. Examples of other products include, but are not limited to, Byk Dynwet 800 (alcohol alkoxylates) and the like.

The concentration of the physical property-adjusting polymer c) is preferably 0.001 to 200 wt.%, relative to the amount of OSC compound. Preferably these polymers are selected from the same group of polymers as described above as viscosity modifiers a).

The composition may also be a "hot melt" type ink, i.e. it is liquid at the injection or printing temperature, but solid at room temperature.

Preferably, the solvent can be at atmospheric or reduced pressure (as low as 10)^-7Torr) and/or heat (up to 500 ℃ C.) to evaporate or sublimeAs required so as to be substantially free of residue. The boiling point of the solvent or the highest boiling point solvent of the solvent mixture is < 400 ℃ at 1Torr and preferably at atmospheric pressure, more preferably < 300 ℃ at 1Torr and preferably at atmospheric pressure, or preferably < 200 ℃ at 20 Torr.

It is further preferred that the boiling point of the solvent, or the boiling point of the lowest boiling solvent of the solvent mixture, is ≥ 130 ℃ and more preferably > 130 ℃ at atmospheric pressure.

If the solvent is a liquid at 25 deg.C, the viscosity of the solvent at 25 deg.C is > 10 cP. The viscosity of the solvent mixture at 25 ℃ was > 10 cP. Preferably the solvent or solvent mixture has a viscosity of > 15cP at 25 deg.C, more preferably > 20cP at 25 deg.C, most preferably > 50cP at 25 deg.C.

The distribution ratio of the solvent (log P), or a weighted average calculation of the distribution ratio of the solvent mixture (log P)_wIs > 1.5, more preferably > 2 and most preferably > 2.5. Preferably these values relate to the calculated log P for each solvent.

The surface tension of the solvent or solvent mixture, without any additives, is preferably > 15dyne/cm and < 80dyne/cm, more preferably > 25dyne/cm and < 60 dyne/cm.

The compositions or inks according to the invention may be used to apply functional materials such as OSC compounds to a substrate or to a device by coating or printing methods such as flexographic printing, gravure printing, ink jet printing, microcontact printing, flexo printing, stamping, etc. Most preferably, the ink is used for flexographic, gravure or inkjet printing.

The size of the printed features may range from about 1 micron diameter or even less of lines or dots, respectively, up to large areas in the range of several square meters, preferably from 10 microns to 1m². The thickness of the printed OSC layer is most preferably from 50 to 300 nm.

Optionally, the composition comprises one or more additives that increase the viscosity of the composition (viscosity modifiers). For example, anOne or more polymers are optionally added in small amounts, preferably 0.001 to 200 wt.%, relative to the amount of OSC compound, to further increase the viscosity. Suitable and preferred polymers include, for example, polystyrene, SeptonPolymers such as Septon4099 (available from Kuraray America inc.), polytriarylamines, etc., or polymers disclosed for use as binders in US2007/0102696 a 1. However, it is preferred that the composition does not comprise any non-volatile additives other than the OSC compound(s).

The solvent may generally be selected from any chemical class that meets the physical criteria described above, including but not limited to aliphatic or aromatic hydrocarbons, amines, thiols, amides, esters, ethers, polyethers, alcohols, glycols, and polyols. Suitable and preferred solvents include, for example, 1-cyclohexyl-2-pyrrolidone (N-cyclohexyl-pyrrolidone), methylated benzenes such as o-, m-or p-xylene, terpenes such as alpha-terpineol, menthol or carveol, naphthols such as decahydro-2-naphthol or 1, 2, 3, 4-tetrahydro-1-naphthol, and methylated cycloaliphatic alcohols such as 3-or 4-methylcyclohexanol or 2, 5-dimethylcyclohexanol.

Preferred solvents having a high viscosity include, for example, decahydro-2-naphthol and 1, 2, 3, 4-tetrahydro-1-naphthol. Suitable solvents having low viscosity that can be used as diluents include, for example, methylated benzenes such as ortho-, meta-, or para-xylene, tetrahydronaphthalene, and decalin.

Particularly preferred are solvent mixtures comprising one or more solvents selected from the high viscosity group and one or more solvents selected from the low viscosity group. The high viscosity group consists of solvents with viscosities > 10cP, preferably > 50cP and < 10000cP, preferably < 5000cP at 25 deg.C, including but not limited to solvents such as decahydro-2-naphthol and 1, 2, 3, 4-tetrahydro-1-naphthol. The low viscosity group consists of solvents with viscosities > 0.25cP, preferably > 0.5cP and < 10cP at 25 deg.C, including but not limited to solvents such as tetrahydronaphthalene, decahydronaphthalene and methylated benzenes such as ortho-, meta-or para-xylene.

More preferred are binary mixtures of o-xylene/decahydro-2-naphthol in the ratio 5/95 to 40/60, furthermore tetrahydronaphthalene/1, 2, 3, 4-tetrahydro-1-naphthol in the ratio 25/75 to 50/50, furthermore decalin/decahydro-2-naphthol in the ratio 25/75 to 50/50 (all proportions are given in wt.%), in particular the binary mixtures shown in table 1 of example 1.

The OSC compounds can be selected from standard materials known to the person skilled in the art and described in the literature.

The OSC compound may be any conjugated aromatic molecule comprising at least three aromatic rings. The OSC compound preferably contains a 5, 6 or 7-membered aromatic ring, and more preferably contains a 5 or 6-membered aromatic ring. The material may be a monomer, oligomer or polymer, including mixtures, dispersions and blends.

Each aromatic ring optionally comprises one or more heteroatoms selected from Se, Te, P, Si, B, As, N, O or S, preferably selected from N, O or S.

The aromatic ring may be optionally substituted with: alkyl, alkoxy, polyalkoxy, thioalkyl, acyl, aryl or substituted aryl, halogen, especially fluorine, cyano, nitro or from-N (R)^x)(R^y) An optionally substituted secondary or tertiary alkylamine or arylamine of formula (I), wherein R^xAnd R^yEach independently is H, optionally substituted alkyl, optionally substituted aryl, alkoxy, or polyalkyl. Wherein R is^xAnd R^yRepresents an alkyl or aryl group, which may be optionally fluorinated.

The rings may optionally be fused or may be linked to a conjugated linking group, such as-C (T)¹)＝C(T²)-、-C≡C-、-N(R^Z)-、-N＝N-、(R^z)C＝N-、-N＝C(R^Z) -, in which T¹And T²Independently of one another represent HCl, F, -C.ident.N-or lower alkyl, preferably C_1-4Alkyl, and R^zRepresents H, optionally substituted alkyl or optionally substituted aryl. Wherein R is^zIs an alkyl or aryl group, which may be optionally fluorinated.

Preferred OSC compounds include small molecules (i.e., monomeric compounds), polymers, oligomers and derivatives thereof, selected from conjugated hydrocarbon polymers such as polyacenes, polyphenylenes, poly (phenylenevinylenes), polyfluorenes including oligomers of those conjugated hydrocarbon polymers; condensed aromatic hydrocarbons such as tetracene,Pentacene, pyrene, perylene, coronene or soluble substituted derivatives of these; oligomeric para-substituted phenylenes such as para-quaterphenyl (P-4P), para-pentabiphenyl (P-5P), para-biphenylene (P-6P), or soluble substituted derivatives of these; conjugated heterocyclic polymers such as poly (3-substituted thiophene), poly (3, 4-disubstituted thiophene), polybenzothiophene, polyisobenzothiophene, poly (N-substituted pyrrole), poly (3, 4-disubstituted pyrrole), polyfuran, polypyridine, poly-1, 3, 4-oxadiazole, polyisobenzothiophene, poly (N-substituted aniline), poly (2-substituted aniline), poly (3-substituted aniline), poly (2, 3-disubstituted aniline), polyazulene, polypyrene; a pyrazoline compound; polyselenophene; a polybenzofuran; a polybenzazole; poly-pyridazine; a biphenylamine compound; a stilbene compound; a triazine; substituted metallic or metal-free porphines, phthalocyanines, fluoro phthalocyanines, naphthalocyanines or fluoro naphthalocyanines; c₆₀And C₇₀Fullerene or a derivative thereof; n, N' -dialkyl, substituted dialkyl, diaryl or substituted diaryl-1, 4, 5, 8-naphthalene tetracarboxylic acid diimides and fluoro derivatives; n, N' -dialkyl, substituted dialkyl, diaryl or substituted diaryl 3, 4, 9, 10-perylenetetracarboxylic diimide (perylenetetracarboxylic diimide); bathophenanthroline; diphenoquinone; 1,3, 4-oxadiazole; 11, 11, 12, 12-tetracyanonaphthalene-2, 6-benzoquinodimethane; alpha, alpha ' -bis (dithieno [3, 2-b2 ', 3 ' -d)]Thiophene); 2, 8-dialkyl, substituted dialkyl, diaryl or substituted diAryl bithiophene anthracenes; 2, 2' -dibenzo [1, 2-b: 4, 5-b']A bithiophene. Preferred compounds are those from the above list and their soluble derivatives.

Preferred OSC compounds are small molecules (i.e. monomeric compounds).

Particularly preferred OSC compounds are substituted polyacenes, such as 6, 13-bis (trialkylsilylethynyl) pentacene or derivatives thereof, as described by way of example in US 6,690,029 or US2007/0102696 a 1.

Further preferred OSC compounds are poly (3-substituted thiophenes), very preferably poly (3-alkylthiophenes) (P3AT), wherein the alkyl group is preferably straight-chain and preferably has 1to 12, most preferably 4 to 10C-atoms, such as poly (3-hexylthiophene).

Particularly preferred OSC compounds are selected from formula I (polyacenes):

wherein R may be the same or different¹、R²、R³、R⁴、R⁵、R⁶、R⁷、R⁸、R⁹、R¹⁰、R¹¹And R¹²Each independently represents hydrogen; optionally substituted C₁-C₄₀Carbyl (carbyl) or hydrocarbyl; optionally substituted C₁-C₄₀An alkoxy group; optionally substituted C₆-C₄₀An aryloxy group; optionally substituted C₇-C₄₀An alkylaryloxy group; optionally substituted C₂-C₄₀An alkoxycarbonyl group; optionally substituted C₇-C₄₀An aryloxycarbonyl group; cyano (-CN); carbamoyl (-C (═ O) NH₂) (ii) a A haloformyl group (-C (═ O) -X, wherein X represents a halogen atom); formyl (-C (═ O) -H); an isocyano group; an isocyanate group; a thiocyanate or thioisocyanate group; an optionally substituted amino group; a hydroxyl group; a nitro group; CF (compact flash)₃A group; halo (Cl, Br, F); or an optionally substituted silyl or alkynylsilyl group; and

wherein each pair R¹And R²、R²And R³、R³And R⁴、R⁷And R⁸、R⁸And R⁹、R⁹And R¹⁰Independently optionally bridged to each other to form C₄-C₄₀A saturated or unsaturated ring which may be substituted by an oxygen atom, a sulfur atom or a compound of formula-N (R)^a) A group of (wherein R is^aIs a hydrogen atom or an optionally substituted hydrocarbon group) or may be optionally substituted; and

wherein one or more carbon atoms of the polyacene skeleton may be optionally substituted by a hetero atom selected from the group consisting of N, P, As, O, S, Se and Te; and

wherein any two or more substituents R located at adjacent ring positions of the polyacene¹-R¹²Independently may optionally together form another optionally substituted group O, S or-N (R)^a) (wherein R is^aAs defined above) inserted C₄-C₄₀A saturated or unsaturated ring or an aromatic ring system fused to a polyacene; and

where n is 0, 1, 2, 3 or 4, preferably n is 0, 1 or 2, most preferably n is 0 or 2, meaning that the polyacene compound is a pentacene compound (if n ═ 2) or a "pseudo (pseudo) pentacene" compound (if n ═ 0).

Very preferred compounds of this formula are those of the sub-formula I1 (substituted pentacenes):

wherein R is¹、R²、R³、R⁴、R⁷、R⁸、R⁹、R¹⁰、R¹⁵、R¹⁶、R¹⁷Each independently being the same or different and each independently representing: h; optionally substituted C₁-C₄₀A carbon or hydrocarbon radical; optionally substituted C₁-C₄₀An alkoxy group; optionally substituted C₆-C₄₀An aryloxy group; optionally substituted C₇-C₄₀An alkylaryloxy group; optionally substituted C₂-C₄₀An alkoxycarbonyl group; optionally substituted C₇-C₄₀An aryloxycarbonyl group; cyano (-CN); carbamoyl (-C (═ O) NH₂) (ii) a A haloformyl group (-C (═ O) -X, wherein X represents a halogen atom); formyl (-C (═ O) -H); an isocyano group; an isocyanate group; a thiocyanate or thioisocyanate group; an optionally substituted amino group; a hydroxyl group; a nitro group; CF (compact flash)₃A group; halogen groups (Cl, Br, F); or an optionally substituted silyl group; and A represents silicon or germanium; and

wherein each pair R¹And R²、R²And R³、R³And R⁴、R⁷And R⁸、R⁸And R⁹、R⁹And R¹⁰、R¹⁵And R¹⁶And R¹⁶And R¹⁷Independently optionally bridged to each other to form C₄-C₄₀A saturated or unsaturated ring optionally substituted by an oxygen atom, a sulfur atom or a compound of formula-N (R)^a) A group of (wherein R is^aIs a hydrogen atom or a hydrocarbyl group), or is optionally substituted; and

wherein one or more carbon atoms of the polyacene skeleton are optionally substituted by a hetero atom selected from the group consisting of N, P, As, O, S, Se and Te, characterized in that

a)R¹、R²、R³、R⁴、R⁷、R⁸、R⁹、R¹⁰At least one of (A) is optionally substituted C₁-C₄₀A carbon or hydrocarbon radical of (a); optionally substituted C₁-C₄₀An alkoxy group; optionally substituted C₆-C₄₀An aryloxy group; optionally substituted C₇-C₄₀An alkylaryloxy group; optionally substitutedC of (A)₂-C₄₀An alkoxycarbonyl group of (a); optionally substituted C₇-C₄₀An aryloxycarbonyl group; cyano (-CN); carbamoyl (-C (═ O) NH₂) (ii) a A haloformyl group (-C (═ O) -X, wherein X represents a halogen atom); formyl (-C (═ O) -H); an isocyano group; an isocyanate group; a thiocyanate or thioisocyanate group; an optionally substituted amino group; a hydroxyl group; a nitro group; CF (compact flash)₃A group; halogen groups (Cl, Br, F); or optionally substituted silyl, and/or

b) At least one pair of R¹And R²、R²And R³、R³And R⁴、R⁷And R⁸、R⁸And R⁹、R⁹And R¹⁰Are bridged to each other to form C₄-C₄₀A saturated or unsaturated ring optionally substituted by an oxygen atom, a sulfur atom or a compound of formula-N (R)^a) A group of (wherein R is^aIs a hydrogen atom or a hydrocarbyl group), or is optionally substituted.

Still further preferred compounds of this formula are those of the sub-formula I2 (substituted heteroacenes):

wherein R is²、R³、R⁸、R⁹、R¹⁵、R¹⁶、R¹⁷Each independently being the same or different and each independently representing: h; optionally substituted C₁-C₄₀A carbon or hydrocarbon radical; optionally substituted C₁-C₄₀An alkoxy group; optionally substituted C₆-C₄₀An aryloxy group; optionally substituted C₇-C₄₀An alkylaryloxy group; optionally substituted C₂-C₄₀An alkoxycarbonyl group; optionally substituted C₇-C₄₀An aryloxycarbonyl group; cyano (-CN); carbamoyl (-C (═ O) NH₂) (ii) a A haloformyl group (-C (═ O) -X, wherein X represents a halogen atom);formyl (-C (═ O) -H); an isocyano group; an isocyanate group; a thiocyanate or thiocyanate group; an optionally substituted amino group; a hydroxyl group; a nitro group; CF (compact flash)₃A group; halogen groups (Cl, Br, F); or an optionally substituted silyl group; and A represents silicon or germanium; and

wherein each pair R²And R³、R⁸And R⁹、R¹⁵And R¹⁶And R¹⁶And R¹⁷Independently optionally bridged to each other to form C₄-C₄₀A saturated or unsaturated ring optionally substituted by an oxygen atom, a sulfur atom or a compound of formula-N (R)^a) A group of (wherein R is^aIs a hydrogen atom or a hydrocarbyl group) inserted, or optionally substituted; and

wherein one or more carbon atoms of the polyacene skeleton are optionally substituted by a hetero atom selected from the group consisting of N, P, As, O, S, Se and Te, characterized in that

R²And R³And R is⁸And R⁹At least one pair of which are bridged to each other to form C₄-C₄₀A saturated or unsaturated ring surrounded by an oxygen atom, a sulfur atom or a compound of formula-N (R)^a) A group of (wherein R is^aIs a hydrogen atom or a hydrocarbyl group), and is optionally substituted.

Still further preferred compounds of formula I are those of the sub-formula I3 (silylethynylated heteroacenes):

wherein

Y¹And Y²One represents-CH or-CH-and the other represents-X-,

Y³and Y⁴One represents-CH or-CH-and the other represents-X-,

x is-O-, -S-, -Se-or-NR' -,

r is (independently of one another in the case of a plurality of occurrences) a cyclic, linear or branched alkyl or alkoxy radical having 1to 20, preferably 1to 8, C atoms or an aryl radical having 2 to 30C atoms, all of which are optionally fluorinated or perfluorinated, and SiR₃Preferably a trialkylsilyl group,

r' is H, F, Cl, Br, I, CN, a linear or branched alkyl or alkoxy radical having 1to 20, preferably 1to 8C atoms and an optionally fluorinated or perfluorinated, aryl radical having 6 to 30C atoms, preferably C₆F₅Or CO₂R 'and R' is H, an optionally fluorinated alkyl group having 1to 20C atoms or an optionally fluorinated aryl group having 2 to 30, preferably 5 to 20C-atoms.

R' is H or a linear or branched alkyl group having 1to 10C atoms, preferably H,

m is 0 or 1, and m is,

o is a number of 0 or 1,

with the proviso that R' is not hydrogen if X is S.

Particularly preferred are compounds of formula I3 wherein m and n are 0, and/or X is S, and/or R' is F.

The term "carbyl" As used above and below denotes any monovalent or polyvalent organic radical moiety comprising at least one carbon atom and either free of any non-carbon atom (such As e.g. -C.ident.C-), or optionally in combination with at least one non-carbon atom such As N, O, S, P, Si, Se, As, Te or Ge (e.g. carbonyl, etc.). The term "hydrocarbyl" denotes a carbyl group additionally comprising one or more H atoms and optionally comprising one or more heteroatoms such As N, O, S, P, Si, Se, As, Te or Ge.

The carbyl or hydrocarbyl group of the chain comprising 3 or more C atoms may also be linear, branched and/or cyclic, comprising spiro and/or fused rings.

Preferred carbyl and hydrocarbyl groups include alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy and alkoxycarbonyloxy, each of these groups being optionally substituted and having from 1to 40, preferably from 1to 25, very preferably from 1to 18, C atoms, and also optionally substituted aryl or aryloxy having from 6 to 40, preferably from 6 to 25, C atoms, and alkylaryloxy, arylcarbonyl, aryloxycarbonyl, arylcarbonyloxy and aryloxycarbonyloxy, each of these groups being optionally substituted and having from 6 to 40, preferably from 7 to 40, C atoms, wherein all these groups optionally contain one or more heteroatoms, in particular heteroatoms selected from the group consisting of N, O, S, P, Si, Se, As, Te and Ge.

The carbyl or hydrocarbyl group may be a saturated or unsaturated acyclic group, or a saturated or unsaturated cyclic group. Unsaturated acyclic or cyclic groups are preferred, especially aryl, alkenyl and alkynyl groups (especially ethynyl). If C₁-C₄₀A carbyl or hydrocarbyl group is acyclic, then the group may be straight-chain or branched. C₁-C₄₀Carbyl or hydrocarbyl groups include, for example: c₁-C₄₀Alkyl radical, C₂-C₄₀Alkenyl radical, C₂-C₄₀Alkynyl, C₃-C₄₀Allyl radical, C₄-C₄₀Alkyldienyl, C₄-C₄₀Polyalkenyl, C₆-C₁₈Aryl radical, C₆-C₄₀Alkylaryl group, C₆-C₄₀Aralkyl radical, C₄-C₄₀Cycloalkyl radical, C₄-C₄₀Cycloalkenyl groups, and the like. Preferred of the above groups are each C₁-C₂₀Alkyl radical, C₂-C₂₀Alkenyl radical, C₂-C₂₀Alkynyl, C₃-C₂₀Allyl radical, C₄-C₂₀Alkyldienyl radical, C₆-C₁₂Aryl and C₄-C₂₀A polyalkenyl group. Also included are combinations of groups having carbon atoms and groups having hetero atoms, e.g. alkynes substituted by silyl, preferably trialkylsilyl groupsAnd a group (preferably ethynyl).

Aryl and heteroaryl preferably denote mono-, di-or tricyclic aromatic or heteroaromatic groups having up to 25 carbon atoms, which may also contain fused rings and are optionally substituted by one or more groups L, wherein L is halogen or alkyl, alkoxy, alkylcarbonyl or alkoxycarbonyl having 1to 12C atoms, wherein one or more H atoms may be replaced by F or Cl.

Particularly preferred aryl and heteroaryl radicals are phenyl, naphthalene, thiophene, selenophene, thienothiophene, dithienothiophene, fluorene and oxazole in which, in addition, one or more CH groups may be replaced by N, all of which may be unsubstituted, mono-or polysubstituted with L as defined above.

In formula I and subformulae thereof, R^1-17Preferably represents a straight-chain, branched or cyclic alkyl radical having 1to 20C atoms, which is unsubstituted or mono-or polysubstituted by F, Cl, Br or I, and one or more non-adjacent CH groups₂The radicals being optionally substituted in each case independently of one another by-O-, -S-, -NR ]⁰-、-SiR⁰R⁰⁰-、-CX¹＝CX²-or-C.ident.C-is replaced in such a way that O and/or S atoms are not directly linked to each other, or represents optionally substituted aryl or heteroaryl having 1to 30C atoms, and R⁰And R⁰⁰Independently of one another, H or alkyl having 1to 12C atoms, and X¹And X²Independently of each other H, F, Cl or CN.

If R is^1-17One of (A) is alkyl or alkoxy, i.e. wherein the terminal CH is₂The group is replaced by-O-, which may be straight-chain or branched. Preferably straight-chain, having 2 to 8C atoms and thus preferably ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, ethoxy, propoxy, butoxy, pentoxy, hexoxy, heptoxy or octoxy, and also, for example, methyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, nonoxy, decyloxy, undecyloxy, dodecyldodecyl, tetradecyl, pentadecyl, nonyloxy, decyloxyAlkoxy, tridecoxy or tetradecoxy. Particularly preferred are n-hexyl and n-dodecyl.

If R is^1-17One of (A) is alkyl, wherein one or more CH₂The group is replaced by-CH ═ CH-, which may be linear or branched. It is preferably straight-chain, has 2 to 12C atoms, and is therefore preferably vinyl, prop-1-, or prop-2-enyl, but-1-, 2-or but-3-enyl, pent-1-, 2-, 3-or pent-4-enyl, hex-1-, 2-, 3-, 4-or hex-5-enyl, hept-1-, 2-, 3-, 4-, 5-or hept-6-enyl, oct-1-, 2-, 3-, 4-, 5-, 6-or oct-7-enyl, non-1-, 2-, 3-, 4-, 5-, 6-, or, 7-or non-8-alkenyl, dec-1-, 2-, 3-, 4-, 5-, 6-, 7-, 8-or dec-9-alkenyl, undec-1-, 2-, 3-, 4-, 5-, 6-, 7-, 8-, 9-or undec-10-alkenyl, dodec-1-, 2-, 3-, 4-, 5-, 6-, 7-, 8-, -9, -10-or undec-11-alkenyl. The alkenyl group may comprise a C ═ C-bond having the E-or Z-configuration, or mixtures thereof.

If R is^1-17One of (A) is oxaalkyl, i.e. one of the CH groups₂Where a radical is replaced by-O-, preference is given to linear 2-oxapropyl (═ methoxymethyl), 2- (═ ethoxymethyl) or 3-oxabutyl (═ 2-methoxyethyl), 2-, 3-, or 4-oxapentyl, 2-, 3-, 4-, or 5-oxahexyl, 2-, 3-, 4-, 5-, or 6-oxaheptyl, 2-, 3-, 4-, 5-, 6-or 7-oxaoctyl, 2-, 3-, 4-, 5-, 6-, 7-or 8-oxanonyl or 2-, 3-, 4-, 5-, 6-, 7-, 8-, or 9-oxadecyl.

If R is^1-17One of (A) is thioalkyl, i.e. one of the CH groups₂The radical being replaced by-S-, it is preferably a linear thiomethyl group (-SCH)₃) 1-Thioethyl (-SCH)₂CH₃) 1-thiopropyl (═ SCH)₂CH₂CH₃) 1- (thiobutyl), 1- (thiopentyl), 1- (thiohexyl), 1- (thioheptyl), 1- (thiooctyl), 1- (thiononyl), 1- (thiodecyl), 1- (thioundecyl) or 1- (thiododecyl), where preferably an sp will be adjacent²CH hybridized with vinyl carbon atom₂Radical substitution。

If R is^1-17One of (A) is a fluoroalkyl group, which is preferably a linear perfluoroalkyl group C_iF₂₁₊₁Wherein i is an integer from 1to 15, especially CF₃、C₂F₅、C₃F₇、C₄F₉、C₅F₁₁、C₆F₁₃、C₇F₁₅Or C₈F₁₇Very preferably C₆F₁₃。

Very preferred is R^1-17Selected from C optionally substituted with one or more fluorine atoms₁-C₂₀Alkyl radical, C₁-C₂₀-alkenyl, C₁-C₂₀-alkynyl, C₁-C₂₀-alkoxy, C₁-C₂₀Thioalkyl, C₁-C₂₀-silyl radical, C₁-C₂₀-amino or C₁-C₂₀-fluoroalkyl, in particular selected from alkenyl, alkynyl, alkoxy, thioalkyl or fluoroalkyl, all of which are linear and have 1to 12, preferably 5 to 12, C atoms, most preferably pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl or dodecyl.

-CX¹＝CX²Preferably, is-CH ═ CH-, -CF ═ CF-or-CH ═ c (cn) -.

R^15-17Preferably identical or different groups selected from the following group: c₁-C₄₀Alkyl, preferably C₁-C₄Alkyl, most preferably methyl, ethyl, n-propyl or isopropyl, C₆-C₄₀Aryl, preferably phenyl, C₆-C₄₀Aryl alkyl, C₁-C₄₀-alkoxy or C₆-C₄₀Arylalkoxy, in which all of these radicals are optionally substituted, for example by one or more halogen atoms. Preferably, R^15-17Each independently selected from optionally substituted C_1-12-alkyl, more preferably C_1-4-alkyl, most preferably C_1-3Alkyl, e.g. isopropyl, and optionally substituted C_6-10Aryl, preferably phenyl. Even more preferred are compounds of formula-SiR¹⁵R¹⁶In which R is⁶Together with the Si atom, form a cyclic silyl group, preferably having 1to 8C atoms.

In a preferred embodiment R^15-17Are the same groups, e.g. the same optionally substituted alkyl groups, as in triisopropylsilyl. Very preferred R^15-17Are identical optionally substituted C_1-10More preferably C_1-4Most preferably C_1-3An alkyl group. The preferred alkyl group in this case is isopropyl.

Preferred radicals-SiR¹⁵R¹⁶R¹⁷Including but not limited to trimethylsilyl, triethylsilyl, tripropylsilyl, dimethylethylsilyl, diethylmethylsilyl, dimethylpropylsilyl, dimethylisopropylsilyl, dipropylmethylsilyl, diisopropylmethylsilyl, dipropylethylsilyl, diisopropylethylsilyl, diethylisopropylsilyl, triisopropylsilyl, trimethoxysilyl, triethoxysilyl, triphenylsilyl, diphenylisopropylsilyl, diisopropylphenylsilyl, diphenylethylsilyl, diethylphenylsilyl, diphenylmethylsilyl, triphenoxysilyl, dimethylmethoxysilyl, dimethylphenoxysilyl, methylmethoxyphenylsilyl, and the like, wherein the alkyl group, the alkyl, Aryl or alkoxy is optionally substituted.

Optionally, the OSC composition comprises one or more organic binders, preferably polymeric binders, as described for example in US2007/0102696 a1, to adjust the rheological properties, preferably in a ratio of binder to OSC compound of 20: 1to 1: 20, preferably 10: 1to 1: 10, more preferably 5: 1to 1: 5, by weight.

The total concentration of the OSC compound in the composition is preferably from 0.1 to 10 wt%, more preferably from 0.5 to 5 wt%. The composition may comprise one or more than one, preferably 1, 2, 3 or more than three OSC compounds.

The compositions according to the invention may additionally comprise one or more further components, such as surface-active compounds, lubricants, wetting agents, dispersants, hydrophobing agents, binders, flow improvers, defoamers, deaerators, diluents which may be reactive or non-reactive, auxiliaries, colorants, dyes or pigments, sensitizers, stabilizers, nanoparticles or inhibitors. However, these further components should not oxidize the OSC or otherwise be able to chemically react with the OSC material or have an electrical doping effect on the OSC.

During the preparation of an OE device, an OSC layer is deposited onto a substrate, followed by removal of the solvent together with any volatile conductive additives present. The OSC layer is preferably deposited from the composition of the present invention by coating or printing techniques as described above and below.

The substrate may be any substrate suitable for the preparation of OE devices, or may also be an OE device or a part thereof. Suitable and preferred substrates are, for example, flexible films of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide or planarized Si glass.

Removal of the solvent and any volatile conductive additives is preferably achieved by evaporation, for example by exposing the deposited layer to elevated temperature and/or reduced pressure, preferably at 50 to 135 ℃.

The thickness of the OSC layer is preferably from 10 nm to 50 microns, more preferably from 20 nm to 5 microns, more preferably from 50 nm to 1 micron, most preferably from 50 nm to 300 nm.

In addition to the materials and methods as described above and below, OE devices and their components can be prepared from standard materials and standard methods, which are known to the person skilled in the art and described in the literature.

A particularly preferred OE device is an OFET, a preferred OFET according to the invention comprising the following components:

-optionally, a substrate (1),

-a gate electrode (2),

-an insulating layer (3) comprising a dielectric,

-a source electrode and a drain electrode (4),

-an OSC layer (5).

Fig. 1 schematically illustrates a Bottom Gate (BG), Bottom Contact (BC) OFET device according to the present invention, comprising a substrate (1), a gate electrode (2), a dielectric layer (3), source and drain electrodes (4), and an OSC layer (5).

Such a device may be prepared by a method comprising the steps of: a gate electrode (2) is applied on the substrate (1), a dielectric layer (3) is applied on top of the gate electrode (2) and the substrate (1), source and drain electrodes (4) are applied on top of the dielectric layer (3) and an OSC layer (5) is applied on top of the electrodes (4) and the dielectric layer (3).

Fig. 2 schematically generally depicts a Top Gate (TG) OFET device according to the present invention, comprising a substrate (1), source and drain electrodes (4), an OSC layer (5), a dielectric layer (3) and a gate electrode (2).

Such a device may be prepared by a method comprising the steps of: the source and drain electrodes (4) are applied onto the substrate (1), the OSC layer (5) is applied on top of the electrodes (4) and the substrate (1), the dielectric layer (3) is applied on top of the OSC layer (5) and the gate electrode (2) is applied on top of the dielectric layer (3).

In the case of a composition for OPV cassettes, the composition preferably comprises or comprises, more preferably consists essentially of, very preferably comprises only: p-type semiconductors and n-type semiconductors, or acceptor and donor materials. Preferred materials of this type are poly (3-substituted thiophenes) or P3AT with C₆₀Or C₇₀Fullerene or modified C₆₀The molecule is PCBM [ (6, 6) -phenyl C61-butyric acid methyl ester]Such as for example disclosed in WO 94/05045 a1, wherein the ratio of P3AT to fullerene is preferably 2 by weight1to 1: 2, more preferably from 1.2: 1to 1: 1.2 by weight.

Fig. 3 and 4 schematically depict generally representative and preferred OPV devices according to the present invention [ see Waldauf et al, appl. phys. lett.89, 233517(2006) ].

The OPV device as shown in fig. 3 preferably comprises:

a low work function electrode (1) (e.g. a metal such as aluminium) and a high work function electrode (2) (e.g. ITO), one of which is transparent,

-a layer (3) (also called "active layer") comprising a hole-transporting material and an electron-transporting material, preferably selected from OSC materials, located between the electrodes (1, 2); the active layer may for example be present as a bilayer or two distinct layers or as a blend or mixture of p-and n-type semiconductors,

an optional conductive polymer layer (4), for example a blend comprising PEDOT: PSS (poly (3, 4-ethylenedioxythiophene): poly (styrenesulfonate)), between the activation layer (3) and the high work function electrode (2) to modify the work function of the high work function electrode to provide a resistive contact of holes,

-an optional coating (5) (for example LiF) on the side of the low work function electrode (1) facing the activation layer (3) to provide a resistive contact to electrons.

The inverted OPV device as shown in fig. 4 preferably comprises:

a low work function electrode (1) (e.g. a metal such as gold), and a high work function electrode (2) (e.g. ITO), one of which is transparent,

-a layer (3) (also called "active layer") comprising a hole-transporting material and an electron-transporting material, preferably selected from OSC materials, located between the electrodes (1, 2); the active layer may for example be present as a bilayer or two distinct layers or as a blend or mixture of p and n type semiconductors,

-an optional conductive polymer layer (4), for example a blend comprising PEDOT: PSS, between the activation layer (3) and the low work function electrode (1) to provide an ohmic contact of electrons,

-an optional coating (5) (e.g. TiO) on the side of the high work function electrode (2) facing the activation layer (3)_xOf (c) to provide a resistive contact for the holes.

The hole transport polymer is, for example, polythiophene. Electron transport materials are for example inorganic materials such as zinc oxide or cadmium selenide, or organic materials such as fullerene derivatives (e.g. PCBM) or polymers (see for example Coakley, k.m. and mcgehe, m.d. chem. mater.2004, 16, 4533). If the bilayer is a blend, an optional annealing step may be necessary to optimize the performance of the device.

It will be appreciated that modifications to the specific embodiments of the invention described above can be made while still falling within the scope of the invention. Each feature disclosed in this specification may be replaced by an alternative feature serving the same, equivalent, or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

All of the features disclosed in this specification may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. In particular, the preferred features of the invention are applicable to all aspects of the invention and may be used in any combination. Likewise, features described in non-essential combinations may be used separately (not in combination).

It will be appreciated that many of the features described above, particularly of the preferred embodiments, are inventive in their own right and not just as part of the specific embodiments of the invention. Independent protection of these features may be sought in addition to or in lieu of the presently claimed invention.

The invention will now be described in more detail with reference to the following examples, which are merely illustrative and do not limit the scope of the invention.

Example 1

Compositions of organic semiconducting compound a were prepared in solvents and solvent mixtures according to the invention as shown in table 1. The solvents and solvent mixtures in Table 1 have a calculated log P or (log P) < 1.5_wAnd all readily dissolve compound a at concentrations > 0.1 wt.%.

Compound A is a mixture of the following isomers

Compound a and methods for its preparation are disclosed in s.subramanian, j.anthony et al, j.am.chem.soc.2008, 130, 2706-.

TABLE 1

¹⁾At 25 ℃ unless otherwise stated

²⁾For a single solvent

³⁾For solvent mixtures

Comparative example 1

Compositions of organic semiconducting compound A in the solvents shown in Table 2 (boiling points all < 400 ℃) were prepared. In all these solvents, the solubility of compound a was < 0.1 wt.%. This indicates that the solvents of table 2 with log P < 1.5 and higher intrinsic (natural) viscosities are poor solvents for OSC compounds compared to those shown in example 1.

Numbering	Description of the solvent or ink	Viscosity of the oil1)[cP]	log P	(A) Solubility of (2)4)
					C1	Ethylene glycol	17.13	-1.369	Insoluble matter
C2	1, 2, 3-propanetriol	934	-1.538	Insoluble matter
					C3	2-pyrrolidone	13.4	-0.16	Insoluble matter
C4	Ethanolamine	19.33	-1.295	Insoluble matter
					C5	Triethanolamine	607.7	-1.226	Insoluble matter
C6	Diethanolamine (DEA)	577	-1.463	Insoluble matter
					C7	Propylene glycol	43.22	-1.037	Insoluble matter
C8	Tripropylene glycol	55.05	-0.513	Insoluble matter
					C9	N- (2-hydroxyethyl-2-pyrrolidone)	58.4	-0.261	Insoluble matter
C10	Cyclopentanol	10.3	0.788	Insoluble matter
					C11	Cyclohexanol	54.5	1.267	Insoluble matter
C12	Benzyl alcohol	5.5	1.104	Insoluble matter

¹⁾At 25 deg.C

⁴⁾At 20 deg.C

Example 2

Bottom gate, bottom contact OFET devices were prepared by flexographic printing of the inks according to the invention.

The substrate PEN (Q65 FA, available from DuPont Teijin Films) was cut into small pieces, which were slightly larger than the gate mask (gatemask). The substrate pieces were then cleaned by sonication in methanol for 2min, rinsed with methanol and dried with compressed air. A gate mask was placed on the cleaned substrate, and an evaporator was used to coat aluminum having a thickness of 30nm, which was used as a gate electrode.

Adding a tackifier Lisicon^TMM009 (commercially available from Merck KgaA, Darmstadt, Germany) was spin coated onto the substrate and Al gate electrode at 1500rpm for 10s, left on a hot plate at 120 ℃ for 20s, and then washed with propan-2-ol at 1500rpm for 10 s.

Then, the dielectric material Lisicon is added^TMD180 (from)Commercially available from Merck KgaA, Darmstadt, Germany) was spin-coated on top of the previous layer at 1500rpm for 30s, and the substrate was then kept on a hot plate at 120 ℃ for 1min and then held under a 254nm UV lamp for 30 s. After this, it was kept on a hot plate at 120 ℃ for 3 min.

The substrate is then treated with a reactive rinse solution Lisicon^TMM008 (commercially available from Merck KgaA, Darmstadt, Germany) was covered for 1min and washed with THF. The substrate is then treated with a reactive rinse solution Lisicon^TMM001 (commercially available from Merck KgaA, Darmstadt, Germany) was covered for 1min and washed with propan-2-ol. A source and drain mask was then placed on the dielectric coated substrate and the Au electrode was evaporated onto the dielectric layer.

The OSC ink was formulated by dissolving 2% of compound (a) in 40% o-xylene and 60% decahydro-2-naphthol (see number 14 in table 1). The OSC ink was printed onto the dielectric layer and Au electrodes with a FLEXI PROOF 100 flexographic printing press using a nip roller consisting of a plurality of squares measuring 5cm by 5cm, 1cm by 1cm, 5mm by 5mm and 2mm by 2mm print area. The conditions used were: anilox roller: 55L/cm wire mesh, volume: 18.09cm³/m²Printing speed: 30, web pressure: 50, roll pressure: 90.

device performance was then analyzed using an Agilent 4155C semiconductor parameter analyzer to measure source and drain currents and gate current (transistor characteristics) as a function of gate voltage. The carrier mobility is calculated by known methods such as the method disclosed in, for example, US2007/0102696 a 1.

The transistor characteristics and the linear and saturated mobility of this device are illustrated in fig. 5. The device has high mobility (linear 0.1 cm)²Vs, saturated 0.3cm²Vs) and good on/off ratio (10)⁵)。

The data show that the inks according to the invention can be printed using flexographic printing techniques and can also form working transistor devices exhibiting high mobility and good on/off ratio.

Claims (12)

1. A process for preparing a composition comprising the step of dissolving an Organic Semiconducting (OSC) compound in a solvent or a solvent mixture comprising two or more solvents, wherein the solvents are selected such that they fulfil the following conditions:

without any additives, the distribution ratio log P of the solvent, or the weighted average distribution ratio (log P) of the solvent mixture_w> 1.5, and

the viscosity of the solvent or solvent mixture without any additives is > 10cP at 25 ℃, and

the boiling temperature of the solvent, or in the case of a solvent mixture the boiling temperature of the highest boiling solvent of the solvent mixture, is < 400 ℃ at a pressure of 1To rr without any additives.

2. The process according to claim 1, characterized in that the OSC compound is dissolved in the solvent or solvent mixture in a concentration of from 0.005 to 50 wt.%.

3. A process according to claim 1 or 2, characterised in that the boiling point of the solvent, or the boiling point of the lowest boiling solvent of the solvent mixture, is > 130 ℃ at atmospheric pressure.

4. A process according to one or more of claims 1to 3, characterized in that the viscosity of the solvent or solvent mixture is > 50cP at 25 ℃.

5. Method according to one or more of claims 1to 4, characterized in that the log P of the solvent, or the weighted average log P of the solvent mixture_wIs > 2.5.

6. A process according to one or more of claims 1to 5, characterized in that the surface tension of the solvent or solvent mixture is > 15dyne/cm and < 80dyne/cm without any additives.

7. The process according to one or more of claims 1to 6, characterized in that the OSC compound is selected from substituted polyacenes or poly (3-substituted thiophenes).

8. The process according to one or more of claims 1to 7, characterized in that the OSC compound is selected from compounds of the formula I3

Wherein

Y¹And Y²One represents-CH or-CH-and the other represents-X-,

Y³and Y⁴One represents-CH or-CH-and the other represents-X-,

x is-O-, -S-, -Se-or-NR' ",

r is, independently of one another in the case of a plurality of occurrences, a cyclic, linear or branched alkyl or alkoxy radical having 1to 20, preferably 1to 8C atoms, or an aryl radical having 2 to 30C atoms, all of which are optionally fluorinated or perfluorinated, and SiR₃Preferably a trialkylsilyl group,

r' is H, F, Cl, Br, I, CN, a linear or branched alkyl or alkoxy radical having 1to 20, preferably 1to 8C atoms, and an optionally fluorinated or perfluorinated, aryl radical having 6 to 30C atoms, preferably C₆F₅Or CO₂R 'and R' are H, optionally fluorinated alkyl having 1to 20C atoms, or optionally fluorinated aryl having 2 to 30, preferably 5 to 20C-atoms,

r' "is H or a linear or branched alkyl group having 1to 10C atoms, preferably H,

m is 0 or 1, and m is,

o is a number of 0 or 1,

provided that if X is S, then R' is not hydrogen.

9. Composition obtainable by a process according to one or more of claims 1to 8, comprising an OSC compound and a solvent or a solvent mixture comprising two or more solvents, characterized in that,

without any additives, the partition ratio of the solvent, c log P, or the weighted average of the solvent mixture (c log P)_wThe content of the organic solvent is more than 1.5,

the viscosity of the solvent or solvent mixture is > 10cP at 25 ℃ without any additives, and

the boiling point of the solvent or solvent mixture without any additives is < 400 ℃ at 1 Torr.

10. Use of a composition according to claim 9 as a coating or printing ink and/or for the preparation of an OE device.

11. OE device comprising a composition according to claim 9.

12. OE device according to claim 11, characterized in that it is selected from the group consisting of Organic Field Effect Transistors (OFETs), Integrated Circuits (ICs), Thin Film Transistors (TFTs), Radio Frequency Identification (RFID) tags, Organic Light Emitting Diodes (OLEDs), Organic Light Emitting Transistors (OLETs), electroluminescent displays, Organic Photovoltaic (OPV) cells, organic solar cells (O-SCs), flexible OPVs and O-SCs, organic laser diodes (O-lasers), organic integrated circuits (O-I C), lighting devices, light sensitive devices, electrode materials, photoconductors, photodetectors, electrophotographic recording devices, capacitors, charge injection layers, schottky diodes, planarization layers, antistatic films, conductive substrates, conductive patterns, photoconductors, electrophotographic devices, organic memory devices, biosensors, and biochips.