HK1178315B - Electrode treatment process for organic electronic devices - Google Patents

Description

Electrode treatment method for organic electronic device

The present invention relates to a method of treating electrodes in Organic Electronic (OE) devices, in particular Organic Field Effect Transistors (OFETs), to devices prepared by the method, and to materials and formulations for use in the method.

Background

Organic Field Effect Transistors (OFETs) are used in display devices and logic capability circuits. Different metals have been used as source/drain electrodes in organic field effect transistors. A widely used electrode material is gold (Au), however its high cost and unfavorable processing properties have shifted the focus to possible alternatives, such as Ag, Al, Cr, Ni, Cu, Pd, Pt, Ni or Ti. Copper (Cu) is a possible alternative electrode material for Au because of its high conductivity, relatively low price and easier availability for common production methods. In addition, copper has been used in the semiconductor industry, and thus it is relatively easy to transfer a large-scale manufacturing method of electronic devices to an organic semiconductor material as a new technology when combined with an already established copper technology for electrodes.

However, when copper is used as an electrode, i.e. as a carrier injection metal, it has drawbacks due to its low work function, which is lower than the level of most modern organic semiconductors.

DE 102005005089a1 describes an OFET comprising copper source and drain electrodes, which are surface modified by providing a copper oxide layer thereon. However, since copper is easily oxidized to Cu in ambient atmosphere₂O and then oxidized to CuO and further to Cu hydroxide, which may thus generate a non-metallic conductive layer on the Cu electrode, which results in limited carrier injection into the semiconductor layer.

There are known methods in the prior art for modifying metal or metal oxide electrodes, for example based on thiol compounds, to improve carrier injection.

For example, US2008/0315191a1 discloses an organic TFT including source and drain electrodes formed of a metal oxide, wherein the surface of the electrode is subjected to a surface treatment by applying a thin film of a thiol compound having a thickness of 0.3 to 1 molecular layer, such as pentafluorobenzenethiol, perfluoroalkyl mercaptan, trifluoromethane mercaptan, pentafluoroethanethiol, heptafluoropropanethiol, nonafluorobutanethiol, sodium butanethiolate, sodium butanolate or aminothiophenol. However, this method is mainly effective for gold electrodes, but not for copper electrodes, because thiol groups form weaker chemical bonds on copper surfaces compared to gold surfaces.

It is therefore an object of the present invention to provide an improved method for modifying metal or metal oxide electrodes or charge injection layers, including but not limited to copper electrodes, in organic electronic devices to overcome the drawbacks of metal electrodes known from the prior art, such as low work function and low oxidative stability. It is a further object to provide improved electrodes and charge injection layers based on metals or metal oxides for use in organic electronic devices, in particular OFETs and OLEDs, and a process for preparing them. It is a further object to provide improved organic electronic devices, in particular OFETs and OLEDs, comprising modified metal or metal oxide electrodes according to the invention, and processes for preparing them. The method, electrode and device should not suffer from the drawbacks of the prior art methods and allow for large scale time, cost and material efficient manufacturing of electronic devices. Other objects of the present invention will become readily apparent to those skilled in the art from the following detailed description.

It was found that these objects can be achieved by providing a method for electrode treatment, a material for use in the method, an electrode treated by the method and a device comprising the treated electrode according to the invention. In particular, the invention relates to a chemical-based treatment process for metal electrodes that improves the work function of the electrodes and their carrier injection into organic semiconductors. This is achieved by providing a method of: the electrode surface is subjected to a self-assembled monolayer (SAM) treatment process with a compound of the chemical type known as Benzotriazole (BTA) or derivatives or structural analogues of these compounds, these being optionally substituted with electron-withdrawing groups such as F or CN, and/or surface-active groups such as thiol or perfluoroalkyl groups. This was found to be a very effective electrode modification method, especially when applied to copper electrodes, which improves the work function of the electrode and thus the carrier injection into the semiconductor layer of the electrode, even in the presence of copper oxide. The surface treatment process according to the invention enables the production of electronic devices, in particular OFETs, with improved source/drain electrodes.

Benzotriazoles are known in the prior art as pharmaceutical compounds and have also been proposed in the inorganic semiconductor industry as passivation materials, primarily for protection in chemical-mechanical polishing processes, such as described in "Review on coater chemical-mechanical polishing (CMP) and post-CMP cleaning in Ultra Large System Integration (ULSI) -An electrochemical permanent", E-E.Yair and Starosvetsky D., electrochemical Acta,52,2007,1825. However, they have not been suggested so far for SAM treatment to improve the work function of metal electrodes in organic electronic devices.

US 2009/0121192a1 discloses a method for enhancing the corrosion resistance of an article comprising an Ag coating deposited on a solderable Cu substrate. This is achieved by exposing the Ag coating to a corrosion resistant composition comprising a multifunctional molecule, wherein the multifunctional molecule comprises at least one nitrogen containing organic functional group that interacts with and protects the Cu surface, and further comprises at least one sulfur containing organic functional group that interacts with and protects the Ag surface. However, although the purpose of this method is to enhance the corrosion resistance of Ag coatings, there is no suggestion or suggestion of a method that alters the properties of the metal and aims to improve its carrier injection when used as an electrode in an organic electronic device.

Disclosure of Invention

The invention relates to a method comprising the following steps:

providing one or more electrodes comprising a metal or metal oxide in an electronic device, and

depositing a layer comprising a compound of formula I as defined below on the surface of said electrode, and

depositing an organic semiconductor on the surface of the electrode covered by the layer comprising the compound of formula I, or in the region between two or more of the electrodes,

wherein

X¹、X²、X³Independently of one another, from the group consisting of-N (H) -, -N =, = N-, -C (R)^X)=、=C(R^x) -and-S-, wherein X¹、X²And X³Is different from-C (R)^x) = C (R)^x)-，

R^xOn each occurrence identically or differently H, SH, NH₂Or a linear or branched alkyl group having 1 to 15C atoms, wherein one or more non-adjacent C atoms are optionally replaced by-O-, -S-, -NR⁰-、-CO-、-CO-O-、-O-CO-、O-CO-O-、-CR⁰=CR⁰⁰-or-C.ident.C-and wherein one or more H atoms are optionally replaced by F, Cl, Br, I or CN,

R¹and R²Independently of one another, F, Cl, P-Sp-or a linear or branched alkyl radical having 1 to 15C atoms, where one or more nonadjacent C atoms are optionally replaced by-O-, -S-, -NR-⁰-、-CO-、-CO-O-、-O-CO-、-O-CO-O-、-CR⁰=CR⁰⁰-or-C ≡ C-and in which one or more H atoms are optionally replaced by F, Cl, Br, I or CN, or represent unsubstituted or substituted by one or more non-aromatic groupsAryl, heteroaryl, aryloxy, heteroaryloxy, arylcarbonyl, heteroarylcarbonyl, arylcarbonyloxy, heteroarylcarbonyloxy, aryloxycarbonyl or heteroaryloxycarbonyl substituted by the group R, or R¹And R²Together with each other and with the 5-membered heterocyclic ring to which they are attached, form an aromatic or heteroaromatic ring which contains 5 to 7 ring atoms and is unsubstituted or substituted by 1,2, 3,4 or 5 radicals R,

R⁰and R⁰⁰Independently of one another, H or an optionally substituted carbyl or hydrocarbyl radical optionally containing one or more heteroatoms,

r is in each case, identically or differently, H, P-Sp-, halogen, -CN, -NC, -NCO, -NCS, -OCN, -SCN, -C (= O) NR⁰R⁰⁰、-C(=O)X⁰、-C(=O)R⁰、-NH₂、-NR⁰R⁰⁰、-SH、-SR⁰、-SO₃H、-SO₂ ^R0、-OH、-NO₂、-CF₃、-SF₅Optionally substituted silyl, optionally substituted carbyl or hydrocarbyl having 1 to 40C atoms optionally substituted and optionally containing one or more heteroatoms,

p is a polymerizable or crosslinkable group,

sp is a spacer group or a single bond,

X⁰is a halogen.

The invention further relates to an electrode, electrode layer or charge injection layer, preferably a source and/or drain electrode, in an electronic device obtainable or obtained by a method as described above and below, preferably in an Organic Electronic (OE) device, very preferably in a top-gate or bottom-gate Organic Field Effect Transistor (OFET).

The invention further relates to an electronic device, preferably an OE device, very preferably a top-gate or bottom-gate OFET, comprising an electrode, an electrode layer or a charge injection layer as described above and below with great preference as source and/or drain electrode, and to a method of manufacturing such a device.

Preferably, the electronic device is selected from the group consisting of Organic Field Effect Transistors (OFETs), Organic Thin Film Transistors (OTFTs), organic Complementary Thin Film Transistors (CTFTs), Integrated Circuit (IC) components, Radio Frequency Identification (RFID) tags, Organic Light Emitting Diodes (OLEDs), electroluminescent displays, flat panel displays, backlights, photodetectors, sensors, logic circuits, memory elements, capacitors, Organic Photovoltaic (OPV) cells, charge injection layers, schottky diodes, planarising layers, antistatic films, conductive substrates or patterns, photoconductors, photoreceptors, electrophotographic devices and electrostatic printing devices.

The invention further relates to novel compounds of formula I. The invention further relates to novel formulations comprising one or more compounds of formula I and optionally one or more solvents. The invention further relates to the use of the novel compounds and formulations in methods as described above and below, and to OE devices comprising the novel compounds or formulations.

Brief Description of Drawings

Fig. 1 schematically depicts a typical top gate OFET according to the present invention.

Fig. 2 schematically depicts an exemplary bottom gate OFET according to the present invention.

Fig. 3 shows the transfer characteristics of an OFET prepared according to the method described in example 1.

Fig. 4 shows the transfer characteristics of an OFET prepared according to the method described in example 2.

Fig. 5 shows the transfer characteristics of an OFET prepared according to the method described in example 3.

Fig. 6 shows the transfer characteristics of an OFET prepared according to the method described in comparative example 1.

Detailed Description

In this context, the terms "electrode", "electrode layer" and "charge injection layer" are used interchangeably. Thus reference to an electrode or electrode layer also includes reference to a charge injection layer and vice versa.

The term "carbyl" As used above and below denotes any monovalent or polyvalent organic group comprising at least one carbon atom and either without any non-carbon atom (such As e.g. -C ≡ 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, for example, 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, including spiro and/or fused rings.

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

The carbyl or hydrocarbyl group can 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). At C₁-C₄₀Where the carbyl or hydrocarbyl group is acyclic, the group may be straight-chain or branched. C₁-C₄₀Carbyl or hydrocarbyl groups include, for example: c₁-C₄₀Alkyl radical, C₁-C₄₀Alkoxy or oxaalkyl, C₂-C₄₀Alkenyl radical, C₂-C₄₀Alkynyl, C₃-C₄₀Allyl radical, C₄-C₄₀Alkadienyl radical, C₄-C₄₀Polyalkenyl radical, C₆-C₁₈Aryl radical, C₆-C₄₀Alkylaryl group, C₆-C₄₀Arylalkyl radical, C₄-C₄₀Cycloalkyl radical, C₄-C₄₀Cycloalkenyl groups, and the like. Among the foregoing groups, each is preferably C₁-C₂₀Alkyl radical, C₂-C₂₀Alkenyl radical, C₂-C₂₀Alkynyl, C₃-C₂₀Allyl radical, C₄-C₂₀Alkadienyl radical, C₆-C₁₂Aryl and C₄-C₂₀A polyalkenyl group. Also included are combinations of groups having carbon atoms and groups having heteroatoms, such as alkynyl groups, preferably ethynyl groups, substituted with silyl groups, preferably trialkylsilyl groups.

"aryl" and "heteroaryl", if used alone or in terms such as "arylcarbonyl" or "heteroarylcarbonyl" and the like, preferably denote a mono-, di-or tricyclic aromatic or heteroaromatic group having up to 25C atoms, which may also include fused rings and which is optionally substituted by one or more groups L as defined above.

Very preferred substituents L are selected from halogen, most preferably F, or alkyl, alkoxy, oxaalkyl, thioalkyl, fluoroalkyl and fluoroalkoxy having 1 to 12C atoms, or alkenyl, alkynyl having 2 to 12C atoms.

Particularly preferred aryl and heteroaryl radicals are phenyl, naphthalene, thiophene, selenophene, thienothiophene, dithienothiophene, fluorene and oxazole in which furthermore one or more CH groups can be replaced by N, all of which can be unsubstituted, mono-or polysubstituted by L as defined above. Very preferred rings are selected from pyrrole, preferably N-pyrrole, pyridine, preferably 2-or 3-pyridine, pyrimidine, thiophene, preferably 2-thiophene, selenophene, preferably 2-selenophene, thieno [3,2-b ] thiophene, thiazole, thiadiazole, oxazole and oxadiazole, particularly preferably thien-2-yl, 5-substituted thien-2-yl or pyridine 3-yl, all of which may be unsubstituted, mono-or polysubstituted by L as described above.

Alkyl or alkoxy (i.e. wherein the terminal CH is₂The group is replaced by-O-), can be linear or branched. Preferably straight-chain, having 2,3, 4,5,6,7 or 8 carbon atoms and thus preferably ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, ethoxy, propoxy, butoxy, pentoxy, hexoxy, heptoxy or octoxy, and for example methyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, nonoxy, decyloxy, undecyloxy, dodecyloxy, tridecyloxy or tetradecyloxy.

In which one or more CH₂The alkenyl group whose group is replaced by-CH = CH-may be straight-chain or branched. Which are preferably straight-chain, have 2 to 10C atoms and are 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-, 7-or non-8-enyl, di-or tri-alkenyl, Dec-1-, 2-, 3-, 4-, 5-, 6-, 7-, 8-, or dec-9-enyl.

Particularly preferred alkenyl is C₂-C₇-1E-alkenyl, C₄-C₇-3E-alkenyl, C₅-C₇-4-alkenyl, C₆-C₇-5-alkenyl and C₇-6-alkenyl, especially C₂-C₇-1E-alkenyl, C₄-C₇-3E-alkenyl and C₅-C₇-4-alkenyl. Examples of particularly preferred alkenyl groups are vinyl, 1E-propenyl, 1E-butenyl, 1E-pentenyl, 1E-hexenyl, 1E-heptenyl, 3-butenyl, 3E-pentenyl, 3E-hexenyl, 3E-heptenyl, 4-pentenyl, 4Z-hexenyl, 4E-hexenyl, 4Z-heptenyl, 5-hexenyl, 6-heptenyl and the like. Groups having up to 5C atoms are generally preferred.

Oxaalkyl (i.e. one of CH)₂The radical being 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, for example. Oxaalkyl (i.e. one of CH)₂The radicals being replaced by-O-, preferably for example straight-chain 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.

In one of CH₂In the alkyl group in which the group is replaced by-O-and one by-CO-, these groups are preferably adjacent. These radicals thus together form carbonyloxy-CO-O-or oxycarbonyl-O-CO-. Preferably this group is straight-chain and has 2 to 6C atoms. Preference is therefore given to acetoxy, propionyloxy, butyryloxy, pentanoyloxy, hexanoyloxy, acetoxymethyl, propionyloxymethyl, butyryloxymethyl, pentanoyloxymethyl, 2-acetoxyethyl, 2-propionyloxy-ethyl, 2-butyryloxyethyl, 3-acetoxypropyl, 3-propionyloxypropyl, 4-acetoxybutyl, methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl, pentoxycarbonyl, methoxycarbonylmethyl, ethoxycarbonylmethyl, propoxycarbonylmethyl, butoxycarbonylmethyl, 2- (methoxycarbonyl) ethyl, 2- (ethoxycarbonyl) ethyl, 2- (propoxycarbonyl) ethyl, 3- (methoxycarbonyl) propyl, 3- (ethoxycarbonyl) propyl, pentanoyloxy, hexanoyloxy, propionyloxymethyl, butyryloxymethyl, 2-acetoxycarbonyl, 3-acetoxycarbonyl, 4-acetoxybutyl, methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl, 4- (methoxycarbonyl) -butyl.

In which two or more CH₂The alkyl groups in which the radicals are replaced by-O-and/or-COO-can be linear or branched. It is preferably straight-chain and has 3 to 12C atoms. It is therefore preferably biscarboxymethyl, 2-biscarboxyethyl, 3-biscarboxypropyl, 4,4-biscarboxy-butyl, 5-biscarboxy-pentyl, 6-biscarboxy-hexyl, 7-biscarboxy-heptyl, 8-biscarboxy-octyl, 9-biscarboxy-nonyl, 10-biscarboxydecyl, bis (methoxycarbonyl) -methyl, 2-bis- (methoxycarbonyl) -ethyl, 3-bis (methoxycarbonyl) -propyl, 4-bis (methoxycarbonyl) -butyl, 5-bis- (methoxycarbonyl) -pentyl, 6-bis (methoxycarbonyl) -hexyl, 7-bis (methoxycarbonyl) -heptyl, 8-bis (methoxycarbonyl) -octyl, bis (ethoxycarbonyl) -methyl, ethyl, propyl, hexyl, 2, 2-bis (ethoxycarbonyl) -ethyl, 3-bis (ethoxycarbonyl) -propyl, 4-bis- (ethoxycarbonyl) -butyl, 5-bis (ethoxycarbonyl) -hexyl.

Thioalkyl (i.e. in which one CH2 group is replaced by-S-), preferably straight-chain thiomethyl (-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 sp is preferably to be reacted with²Hetero CH with adjacent vinyl carbon atoms₂The groups are replaced.

The fluoroalkyl group is preferably a linear perfluoroalkyl group C_iF_2i+1Wherein i is an integer from 1 to 15, especially CF₃、C₂F₅、C₃F₇、C₄F₉、C₅F₁₁、C₆F₁₃、C₇F₁₅Or C₈F₁₇Very preferably C₆F₁₃。

The above-mentioned alkyl, alkoxy, alkenyl, oxaalkyl, thioalkyl, carbonyl and carbonyloxy groups may be achiral or chiral groups. Particularly preferred chiral groups are, for example, 2-butyl (= 1-methylpropyl), 2-methylbutyl, 2-methylpentyl, 3-methylpentyl, 2-ethylhexyl, 2-propylpentyl, in particular 2-methylbutyl, 2-methylpentyl, 3-methylpentyl, 2-ethylhexyloxy, 1-methylhexyloxy, 2-octyloxy, 2-oxa-3-methylbutyl, 3-oxa-4-methylpentyl, 4-methylhexyl, 2-hexyl, 2-octyl, 2-nonyl, 2-decyl, 2-dodecyl, 6-methoxyoctyloxy, 6-methyloctyloxy, 2-decyloxy, 2-dodecyloxy, 3-methylpentyl, 2-ethylhexyloxy, 2, 5-methylheptyloxy-carbonyl, 2-methylbutyryloxy, 3-methylpentanoyloxy, 4-methylhexanoyloxy, 2-chloropropoyloxy, 2-chloro-3-methylbutyryloxy, 2-chloro-4-methylpentanoyloxy, 2-chloro-3-methylpentanoyloxy, 2-methyl-3-oxapentyl, 2-methyl-3-oxahexyl, 1-methoxypropyl-2-oxy, 1-ethoxypropyl-2-oxy, 1-propoxypropyl-2-oxy, 1-butoxypropyl-2-oxy, 2-fluorooctyloxy, 2-fluorodecyloxy, 1,1, 1-trifluoro-2-octyloxy, 2-fluorodecyloxy, 2-methylbutanoyloxy, 2-methylpentanoyloxy, 2-chloropentanoyloxy, 2-methylhexanoyloxy, 2-chloropropoyloxy, 2-methoxypropyl-2-, 1,1, 1-trifluoro-2-octyl group and 2-fluoromethyl octyloxy group. Very preferred are 2-hexyl, 2-octyl, 2-octyloxy, 1,1, 1-trifluoro-2-hexyl, 1,1, 1-trifluoro-2-octyl and 1,1, 1-trifluoro-2-octyloxy.

Preferred achiral branched groups are isopropyl, isobutyl (= methylpropyl), isopentyl (= 3-methylbutyl), tert-butyl, isopropoxy, 2-methyl-propoxy and 3-methylbutoxy.

-CY¹=CY²-is preferably-CH = CH-, -CF = CF-or-CH = c (cn) -.

Halogen is F, Cl, Br or I, preferably F, Cl or Br.

The polymerizable or crosslinkable groups P in formula I and its subformulae are groups which are capable of participating in polymerization reactions, such as radical or ionic chain polymerization, polyaddition or polycondensation, or which are capable of being grafted onto the polymer backbone in a polymer-analogous transformation reaction, for example by condensation or addition. Especially preferred are polymerizable groups for chain polymerization reactions, such as free radical, cationic or anionic polymerization. Very preferred are polymerizable groups containing a C-C double or triple bond, and polymerizable groups capable of polymerization by a ring-opening reaction, such as oxetanes or epoxides.

Preferably, the polymerizable or crosslinkable group P is selected from CH₂=CW¹-CO-O-、CH₂=CW¹-CO-、CH₂=CW²-(O)_k1-、CW¹=CH-CO-(O)_k3-、CW¹=CH-CO-NH-、CH₂=CW¹-CO-NH-、CH₃-CH=CH-O-、(CH₂=CH)₂CH-OCO-、(CH₂=CH-CH₂)₂CH-O-CO-、(CH₂=CH)₂CH-O-、(CH₂=CH-CH₂)₂N-、(CH₂=CH-CH₂)₂N-CO-、HO-CW²W³-、HS-CW²W³-、HW²N-、HO-CW²W³-NH-、CH₂=CH-(CO-O)_k1-Phe-(O)_k2-、CH₂=CH-(CO)_k1-Phe-(O)k₂-, Phe-CH = CH-, HOOC-, OCN-and W⁴W⁵W⁶Si-, in which W¹Is H, F, Cl, CN, CF³Phenyl or alkyl having 1 to 5C atoms, especially H, Cl or CH₃，W²And W³Independently of one another, H or alkyl having 1 to 5C atoms, in particular H, methyl, ethyl or n-propyl, W⁴、W⁵And W⁶Independently of one another Cl, oxaalkyl or oxacarbonylalkyl having 1 to 5C atoms, W⁷And W⁸Independently of one another H, Cl or alkyl having 1 to 5C atoms, Phe is 1, 4-phenylene which is optionally substituted by one or more radicals L as defined above, k₁、k₂And k₃Independently of one another, 0 or 1, k₃Preferably 1 and k₄Is an integer from 1 to 10.

Particularly preferred radicals P are CH₂=CH-CO-O-、CH₂=C(CH₃)-CO-O-、CH₂=CF-CO-O-、CH₂=CH-O-、(CH₂=CH)₂CH-O-CO-、(CH₂=CH)₂CH-O-、Or a protected derivative thereof. More preferably, the group P is selected from the group consisting of vinyloxy, acrylate, methacrylate, fluorinated acrylic acidEsters, chlorinated acrylates, oxetanes (oxetanes) and epoxy groups, very preferably from epoxy groups, oxetane groups, acrylate groups and methacrylate groups.

The polymerization of the radicals P can be carried out according to methods known to the person skilled in the art and described in the literature, for example in D.J.Broer; G.Challa; G.N.mol, Macromol.Chem,1991,192, 59.

The term "spacer group" is known in the art and suitable spacer groups Sp are known to the person skilled in the art (see, for example, Pure appl. chem.73(5),888 (2001). spacer group Sp is preferably of the formula Sp ' -X ' such that P-Sp-is P-Sp ' -X ', wherein P-Sp-is P-Sp ' -X

Sp' is an alkylene radical having up to 30C atoms, which is unsubstituted or mono-or polysubstituted by F, Cl, Br, I or CN, one or more non-adjacent CH groups₂The radicals may also be substituted, in each case independently of one another by-O-, -S-, -NH-, -NR-⁰-、-SiR⁰R⁰⁰-, -CO-, -COO-, -OCO-O-, -S-CO-, -CO-S-, -CH = CH-or-C.ident.C-in such a way that O and/or S atoms are not bonded directly to one another,

x' is-O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, -CO-NR⁰-、-NR⁰-CO-、-NR⁰-CO-NR⁰⁰-、-OCH₂-、-CH₂O-、-SCH₂-、-CH₂S-、-CF₂O-、-OCF₂-、-CF₂S-、-SCF₂-、-CF₂CH₂-、-CH₂CF₂-、-CF₂CF₂-、-CH=N-、-N=CH-、-N=N-、-CH=CR⁰-、-CY¹=CY²-, -C.ident.C-, -CH = CH-COO-, -OCO-CH = CH-or a single bond,

R⁰and R⁰⁰Each independently of the others, represents H or an alkyl radical having 1 to 12C atoms,

and is

Y¹And Y²Are respectively independently substitutedTable H, F, Cl or CN.

X' is preferably-O-, -S-, -OCH₂、-CH₂O-、-SCH₂-、-CH₂S-、-CF₂O-、-OCF₂-、-CF₂S-、-SCF₂-、-CH₂CH₂-、-CF₂CH₂-、-CH₂CF₂-、-CF₂CF₂-、-CH=N-、-N=CH-、-N=N-、-CH=CR⁰-、-CY¹=CY²-, -C.ident.C-or a single bond, in particular-O-, -S-, -C.ident.C-, -CY¹=CY²-or a single bond. In another preferred embodiment, X' is a group capable of forming a conjugated system, such as-C.ident.C-or-CY¹=CY²-or a single bond.

Typical spacer groups Sp' are, for example- (CH)₂)_p-、-(CH₂CH₂O)_q-CH₂CH₂-、-CH₂CH₂-S-CH₂CH₂-or-CH₂CH₂-NH-CH₂CH₂-or- (SiR)⁰R⁰⁰-O)_p-, where p is an integer from 2 to 12, q is an integer from 1 to 3, and R⁰And R⁰⁰Have the meaning given above.

Preferred radicals Sp' are, for example, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, octadecylene, ethyleneoxyethylene, methyleneoxybutylene, ethylene-thioethylene, ethylene-N-methyliminoethylene, 1-methylalkylene, ethenylene, propenylene and butenylene.

Preferably in the compounds of formula I, R¹And R²Together with the 5-membered heterocyclic ring to which they are attached, form an aromatic or heteroaromatic ring which contains 5 to 7 ring atoms and is unsubstituted or substituted by 1,2, 3,4 or 5 radicals R. Very preferably, R¹And R²Together with each other and the 5-membered heterocyclic ring to which they are attached form a benzene ring, wherein one or two CH groups are optionally substituted by NMost preferred are benzene, pyridine or pyrimidine rings, and wherein said rings are unsubstituted or substituted by 1,2, 3 or 4 groups R, which groups are very preferably selected from non-aromatic groups.

The compound of formula I is preferably selected from the group consisting of formula I1

Wherein

X¹is-N (H) -, -C (R)^x) either-or-S-,

X²is-N =, -N (H) -, -C (R)^x) either-or-S-,

X³is-N = or-N (H) -,

r is 0,1, 2,3 or 4,

and R is^xAnd R has the meaning given above in formula I.

Preferred compounds of formula I1 are selected from the following subformulae:

wherein R is^xR and R are as defined in formula I1. R^xPreferably H, SH, NH₂-alkylene-SH, wherein alkylene represents a linear or branched alkylene group having 1 to 18C atoms, or C₁-C₁₈Thiaalkyl (thioalkyl). R preferably represents, identically or differently on each occurrence, F or C₁-C₁₅Perfluoroalkyl, very preferably F or perfluoroalkyl having 1,2, 3 or 4C atoms.

Further preferably comprises at leastA group R and/or R representing P-Sp^xAnd their preferred compounds of the sub-formulae I11-I15, wherein Sp is a spacer group or a single bond as defined above and P is a polymerizable or crosslinkable group as defined above.

Preferred compounds of formula I11 are selected from the following subformulae:

wherein R is^fIs a linear or branched perfluoroalkyl radical having 1 to 15C atoms, which is preferably linear and/or preferably has 1,2, 3 or 4C atoms. Particularly preferred are compounds of the formulae I11e, I11f and I11g, in which R^fIs CF₃、C₂F₅、n-C₃F₇Or n-C₄F₉。

Preferred compounds of formula I12 are selected from the following subformulae:

wherein R is^fIs a linear or branched perfluoroalkyl radical having 1 to 15C atoms, which is preferably linear and/or preferably has 1,2, 3 or 4C atoms. Especially preferred are compounds of the formulae I12e, I12f and I12g, wherein R^fIs CF₃、C₂F₅、n-C₃F₇Or n-C₄F₉。

Preferred compounds of formula I13 are those wherein R^xThose which are H, very preferably selected from the following subformulae:

wherein R is^fIs a linear or branched perfluoroalkyl radical having 1 to 15C atoms, which is preferably linear and/or preferably has 1,2, 3 or 4C atoms. Especially preferred are compounds of the formulae I13e, I13f and I13g, wherein R^fIs CF₃、C₂F₅、n-C₃F₇Or n-C₄F₉。

Further preferred compounds of the formula I13 are those wherein R^xThose which are SH, very preferably selected from the following subformulae:

wherein R is^fIs a linear or branched perfluoroalkyl radical having 1 to 15C atoms, which is preferably linear and/or preferably has 1,2, 3 or 4C atoms. Especially preferred are compounds of the formulae I13n, I13o and I14p, wherein R^fIs CF₃、C₂F₅-C₃F₇Or n-C₄F₉。

Further preferred compounds of the formula I13 are those wherein R^xThose which are alkylene-SH, where "alkylene" denotes straight-chain or branched alkylene groups having 1 to 18C atoms, very preferably 1 to 12C atoms. These compounds are very preferably selected from the following subformulae:

wherein R is^fIs a linear or branched perfluoroalkyl radical having 1 to 15C atoms, which is preferably linear and/or preferably has 1,2, 3 or 4C atoms. Especially preferred are compounds of the formulae I13u, I13v and I13w, wherein R^fIs CF₃、C₂F₅、n-C₃F₇Or n-C₄F₉。

Preferred compounds of formula I14 are those wherein R^xThose which are SH, very preferably selected from the following subformulae:

wherein R is^fIs a linear or branched perfluoroalkyl radical having 1 to 15C atoms, which is preferably linear and/or preferably has 1,2, 3 or 4C atoms. Especially preferred are compounds of the formulae I14e, I14f and I14g, wherein R^fIs CF₃、C₂F₅、n-C₃F₇Or n-C₄F₉。

Further preferred compounds of the formula I14 are those wherein R^xThose which are alkylene-SH, where "alkylene" denotes straight-chain or branched alkylene groups having 1 to 18C atoms, very preferably 1 to 12C atoms. These compounds are very preferably selected from the following subformulae:

wherein R is^fIs a linear or branched perfluoroalkyl radical having 1 to 15C atoms, which is preferably linear and/or preferably has 1,2, 3 or 4C atoms. Especially preferred are compounds of the formulae I14n, I14o and I14p, wherein R^fIs CF₃、C₂F₅、n-C₃F₇Or n-C₄F₉。

Preferred compounds of formula I15 are selected from the following subformulae:

wherein R is^fIs a linear or branched perfluoroalkyl radical having 1 to 15C atoms, which is preferably linear and/or preferably has 1,2, 3 or 4C atoms, and R^xAs defined in formula I1, and very preferably H, SH or NH₂. Especially preferred are compounds of the formulae I15e, I15f and I15g, wherein R^fIs CF₃、C₂F₅、n-C₃F₇Or n-C₄F₉. Further preferred are compounds of formula I15 a-I15 g, wherein R is^xIs NH₂。

Compounds of formula I and their subformulae are commercially available, for example from ACES Pharma (US), or may be synthesized by conventional synthetic methods known to the skilled person and described in the literature.

Another aspect of the present invention are novel compounds of formula I preferably selected from the above preferred subformulae and preferred embodiments.

Further aspects of the invention are the use of the novel compounds and formulations in methods as described above and below, and OE devices comprising the novel compounds or formulations.

In the method according to the invention, the compounds of the formula I preferably form a self-assembled monolayer (SAM) on the electrode surface, which preferably can be formed, preferably via a 5-membered heterocycle and/or a group R^xTo provide chemical bonding or electrostatic interaction with the electrode surface, and wherein the group R¹And/or R²Or the ring formed by these groups faces the OSC layer.

In addition, the layers formed from the compounds of formula I have improved surface properties, including but not limited to charge injection and transport, on the surface facing the OSC layer. This is achieved by selecting suitable substituents R on the phenyl ring in the compounds of the formula I¹Or R²Or suitable substituents R, preferably selected from halogens, in particular F or Cl, or polyfluorinated or perfluorinated carbon-or hydrocarbon groups, in particular perfluoroalkyl or perfluoroalkoxy groups.

Thus, the use of a SAM of the compound of formula I may reduce the contact resistance between the electrode surface and the OSC layer and improve the injection of carriers into the OSC layer.

The SAM of the compound of formula I may be applied by vacuum or vapour deposition methods, such as physical vapour deposition (PVS) or Chemical Vapour Deposition (CVD) or sublimation, or by liquid coating methods. Preferably, a solvent-based liquid coating method is used.

The SAM of the compound of formula I is preferably applied by depositing a formulation, preferably a solution, comprising one or more compounds of formula I and further comprising one or more organic solvents on the electrode, followed by evaporation of the solvent. Preferred deposition techniques include, but are not limited to, dip coating, spin coating, ink jet printing, letter-press printing, screen printing, doctor blade coating, roll printing, reverse roll printing, lithography, flexographic printing, screen (web) printing, spraying, brushing, or pad printing.

The step of applying a SAM of the compound of formula I to the electrode is hereinafter also referred to as "SAM treatment".

Suitable solvents are selected from the group consisting of, but not limited to, alcohols such as methanol, ethanol, isopropanol, organic ketones such as acetone, 2-heptanone, cyclohexanone, linear and cyclic ethers such as THF, butylphenyl ether, 4-methylanisole, aromatic hydrocarbons such as toluene, mesitylene, cyclohexylbenzene and halogenated hydrocarbons such as mono-or di-or trichlorobenzene, and mixtures thereof.

The concentration of the compound of formula I in the formulation or solution is preferably 0.01-10 wt.%, preferably 0.01-5 wt.%, very preferably 0.05-0.2 wt.%.

Another aspect of the present invention is a formulation comprising one or more compounds of formula I and one or more solvents, preferably selected from the solvents mentioned above.

The electrodes may be applied by solvent-based or liquid coating methods, such as spray coating, dip coating, mesh coating or spin coating, or by vacuum or vapor deposition methods such as physical vapor deposition (PVS) or Chemical Vapor Deposition (CVD) or sublimation. Suitable deposition methods are known to the skilled worker and are described in the literature.

Suitable and preferred electrode materials include metals such as Au, Ag, Cu, Al, Ni and their oxides, mixtures of these metals and/or their oxides, sputter-coated or evaporated particles of metals such as Cu, Cr, Pt/Pd or mixed metal oxides such as Indium Tin Oxide (ITO). Preferably, the electrodes comprise or consist of a metal and/or their oxide, wherein the metal is selected from the group consisting of Au, Ag, Cu, Al and Ni, very preferably from the group consisting of Au, Ag and Cu, most preferably Cu.

Preferably, the electrode is subjected to a pre-cleaning step prior to the SAM treatment. The washing step preferably comprises an acidic wash with an organic or inorganic acid, such as acetic acid, citric acid or HCl.

In a preferred embodiment of the invention, the cleaning of the electrode and the SAM treatment are combined into a single step. This single step is carried out, for example, by applying the compound of formula I dissolved in an organic or inorganic acid, such as acetic acid, citric acid or HCl, to the electrode.

Another aspect of the invention are formulations comprising one or more compounds of formula I and one or more organic or inorganic acids, such as acetic acid, citric acid or HCl.

In another preferred embodiment of the invention, the cleaning of the electrode and the SAM treatment are performed in two separate method steps. For example, the electrode is washed with an acid, such as acetic acid, and then a compound of formula I, preferably dissolved in a suitable solvent, is applied to the washed electrode.

If the SAM treatment is applied to the electrode in a separate step (i.e. separate from the washing or other process step), the concentration of the compound of formula I in the formulation is preferably 0.01 to 5 wt%. Preferably, the solvent is selected from aliphatic ketones, such as acetone or Methyl Butyl Ketone (MBK), lower alkyl alcohols such as ethanol and Isopropanol (IPA), linear or cyclic ethers such as THF, and other organic solvents that dissolve the compound of formula I.

The time for soaking the electrode with the formulation comprising the compound of formula I is preferably from 30s to 1 h. Optionally, the SAM layer is annealed at an elevated temperature, preferably 30-150 ℃, after deposition. The annealing time is preferably from 30s to 5min, very preferably from 30s to 2 min.

If the cleaning of the electrode and the SAM treatment are combined in a single step, the compound of formula I is preferably dissolved in a dilute organic or inorganic acid such as acetic acid, citric acid or HCl, for example 1% acetic acid, preferably at a concentration of 0.01-10% by weight. The time for soaking the electrode with the acid formulation comprising the compound of formula I is preferably 30s to 1 h. Optionally, the SAM layer is annealed at an elevated temperature, preferably 30-150 ℃, after deposition. The annealing time is preferably from 30s to 5min, very preferably from 30s to 2 min.

Preferably, the method according to the invention comprises the following steps:

a) the source and drain electrodes are deposited on the substrate or on the gate insulating layer for example by evaporation,

b) the source and drain electrodes are optionally cleaned,

c) depositing a layer of a compound of formula I or a formulation comprising a compound of formula I and optionally one or more solvents in the region between the source and drain electrodes and optionally on the surface of the source and drain electrodes, optionally removing any solvent present and optionally annealing the layer of a compound of formula I,

d) depositing a layer of an Organic Semiconductor (OSC) or a formulation comprising an OSC onto the source and drain electrodes, for example by spin coating or liquid printing, and onto the layer comprising the compound of formula I, optionally removing the solvent still present, and optionally annealing the OSC layer,

wherein optionally steps b) and c) are combined into a single step.

Another preferred embodiment of the present invention relates to a process for the preparation of OFETs, which comprises the following steps:

a) a source electrode and a drain electrode are deposited on the substrate,

b) the source and drain electrodes are optionally cleaned,

c) depositing a layer of a compound of formula I or a formulation comprising a compound of formula I and optionally one or more solvents in the region between the source and drain electrodes and optionally on the surface of the source and drain electrodes, optionally removing any solvent present and optionally annealing the layer of a compound of formula I,

d) depositing a layer of an Organic Semiconductor (OSC) or a formulation comprising an OSC on the source and drain electrodes and on the layer comprising the compound of formula I, optionally removing the solvent still present and optionally annealing the OSC layer,

e) a gate insulating layer is deposited on the OSC layer,

f) a gate electrode is deposited on the gate insulating layer,

g) a passivation layer is optionally deposited on the gate electrode,

wherein optionally steps b) and c) are combined into a single step.

Steps b) and c) may be combined into a single step, for example, by: applying the cleaning formulation to the source and drain electrodes comprising the compound of formula I, optionally removing solvent still present, and optionally annealing the layer of the compound of formula I.

In the process according to the invention as described in the general and preferred embodiments above and below, only one compound of formula I may be used, or two or more compounds of formula I may be used.

When fabricating a top-gate (TG) transistor, typically the source and drain electrodes are applied to a substrate as in step a) of the above-described method, followed by steps b) -e). A gate insulating layer is then applied over the OSC layer, and a gate electrode is applied over the gate insulating layer.

When preparing a bottom-gate (BG) transistor, typically a gate electrode is first applied on a substrate, a gate insulating layer is applied on the gate electrode, and then a source electrode and a drain electrode are applied on the gate insulator, as in step a) of the above-described method, followed by steps b) -e).

The exact process conditions can be easily adapted and optimized for the respective insulator and the OSC material used.

The thickness of the layer comprising the compound of formula I provided on the electrode (after removal of the solvent) in the electronic device according to the invention is preferably from 1 to 10 molecular layers.

Fig. 1 is a schematic diagram of a typical TG OFET according to the present invention, which includes source (S) and drain (D) electrodes (2) provided on a substrate (1), a SAM layer (3) of a compound of formula I provided on the S/D electrodes, an OSC material layer (4) provided on the S/D electrodes and the SAM layer (3), a dielectric material layer (5) provided on the OSC layer (4) as a gate insulating layer, a gate electrode (6) provided on the gate insulating layer (5), and an optional passivation or protection layer (7) provided on the gate electrode (6) to shield it from further layers or devices that may be provided later or to protect it from environmental influences. The region between the source and drain electrodes (2) is the channel region, as indicated by the double arrow.

Fig. 2 is a schematic diagram of a typical BG, bottom contact OFET according to the present invention, comprising a gate electrode (6) provided on a substrate (1), a dielectric material layer (5) (gate insulating layer) provided on the gate electrode (4), a source (S) and drain (D) electrode (2) provided on the gate insulating layer (6), a SAM layer (3) of a compound of formula I provided on the S/D electrode, an OSC material layer (4) provided on the S/D electrode and the SAM layer (3), and an optional passivation or protection layer (7) provided on the OSC layer (4) to shield it from further layers or devices that may be provided later or to protect it from environmental influences.

The OSC materials and methods used for applying the OSC layer may be selected from standard materials and methods known to those skilled in the art and are described in the literature.

The OSC material may be an n-or p-type OSC, which may be deposited by vacuum or vapour deposition, or preferably from solution. Preferably, use is made of a material having a thickness greater than 1x10^-5cm²V^-1s^-1The FET mobility OSC material of (1).

The OSC is used, for example, as an active channel material in OFETs or as a layer element of organic rectifying diodes. Preferred are OSCs that are deposited by liquid coating to allow environmental processing. The OSC is preferably spray coated, dip coated, mesh coated or spin coated, or deposited by any liquid coating technique. Inkjet deposition is also suitable. The OSC may optionally be vacuum or vapour deposited.

The semiconductor channel may also be a composite of two or more semiconductors of the same type. Furthermore, for the effect of doping the layer, p-type channel material may be mixed with n-type material, for example. Multiple semiconductor layers may also be used. For example, the semiconductor may be inherently near the insulator interface and the highly doped region may additionally be subsequently coated on the intrinsic layer.

The OSC may be a monomeric compound (also referred to as a "small molecule", as compared to a polymer or macromolecule) or a polymeric compound, or a mixture, dispersion or blend comprising one or more compounds selected from one or both of monomeric and polymeric compounds.

In the case of monomeric materials, the OSC is preferably a conjugated aromatic molecule and preferably comprises at least three aromatic rings. Preferred monomeric OSCs are selected from conjugated aromatic molecules comprising a 5,6 or 7 membered aromatic ring, more preferably a 5 or 6 membered aromatic ring.

In these conjugated aromatic molecules, each aromatic ring optionally comprises one or more heteroatoms selected from Se, Te, P, Si, B, As, N, O or S, preferably from N, O or S. Additionally or alternatively, in these conjugated aromatic molecules, each aromatic ring is optionally substituted by alkyl, alkoxy, polyalkoxy, thiaalkyl, acyl, aryl or substituted aryl, halogen, especially fluorine, cyano, nitro or by-N (R)³)(R⁴) Optionally substituted secondary or tertiary alkyl or aryl amines of wherein R³And R⁴Each independently is H, optionally substituted alkyl, or optionally substituted aryl, alkoxy or polyalkoxy. At R³And R⁴In the case of alkyl or aryl, these are optionally fluorinated.

In these conjugated aromatic molecules, the aromatic rings are optionally fused or optionally linked via a conjugated linking group such as-C (T)¹)=C(T²) -, -C.ident.C-, -N (R '), -N = N-, (R') = N-, -N = C (R ') -are linked to each other, wherein T ≡ C-, -N (R'), -are linked to each other¹And T²Each independently represents H, Cl, F, -C ≡ N or C₁-C₁₀Alkyl, preferably C_1-4An alkyl group; r' represents H, optionally substituted C₁-C₂₀Alkyl or optionally substituted C₄-C₃₀And (4) an aryl group. In case R' is alkyl or arylThese are optionally fluorinated.

Further preferred OSC materials that can be used in the present invention include compounds, oligomers and compound derivatives selected from the group consisting of: conjugated hydrocarbon polymers such as polyacenes, polyphenylenes, poly (phenylenevinylenes), polyfluorenes including oligomers of those conjugated hydrocarbon polymers; fused aromatic hydrocarbons such as tetracene, chrysene, 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-hexabiphenyl (P-6P) or soluble substituted derivatives of these; conjugated heterocyclic polymers such as poly (3-substituted thiophenes), poly (3, 4-disubstituted thiophenes), optionally substituted polythieno [2,3-b]Thiophene, optionally substituted polythieno [3,2-b ]]Thiophene, poly (3-substituted selenophene), polybenzothiophene, polydibenzothiophene (polyisothianapthene), poly (N-substituted pyrrole), poly (3, 4-disubstituted pyrrole), polyfuran, polypyridine, poly-1, 3, 4-oxadiazole, polydibenzothiophene, 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 C₇₀A fullerene; n, N' -dialkyl, substituted dialkyl, diaryl or substituted diaryl-1, 4,5, 8-naphthalenetetracarboxylic diimide and fluoro derivatives; n, N' -dialkyl, substituted dialkyl, diaryl or substituted diaryl 3,4,9, 10-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 dialkynyl bisthiophene anthracene; 2,2 '-dibenzo [1,2-b:4,5-b']A bithiophene. Preferred compounds are those from the above list and their organic solvent soluble derivatives.

Particularly preferred OSC materials are selected from polymers and copolymers comprising one or more repeating units selected from: thiophene-2, 5-diyl, 3-substituted thiophene-2, 5-diyl, selenophene-2, 5-diyl, 3-substituted selenophene-2, 5-diyl, optionally substituted thieno [2,3-b ] thiophene-2, 5-diyl, optionally substituted thieno [3,2-b ] thiophene-2, 5-diyl, optionally substituted 2,2 '-bisthiophene-5, 5' -diyl, optionally substituted 2,2 '-bistelenophene-5, 5' -diyl.

Further preferred OSC materials are selected from substituted oligoacenes such as pentacene, tetracene or anthracene, or heterocyclic derivatives thereof, such as 6, 13-bis (trialkylsilylethynyl) pentacene or 5, 11-bis (trialkylsilylethynyl) anthracenedithiophene, for example as disclosed in US6,690,029, WO 2005/055248a1 or US 7,385,221.

In another preferred embodiment of the invention, the OSC layer comprises one or more organic binders to adjust the rheological properties, in particular organic binders having a low dielectric constant of 3.3 or less at 1,000Hz, for example in WO 2005/055248a 1.

The binder is for example selected from poly (. alpha. -methylstyrene), polyvinyl cinnamate, poly (4-vinylbiphenyl) or poly (4-methylstyrene), or blends thereof. The binder may also be a semiconducting binder, for example selected from a polyarylamine, a polyfluorene, a polythiophene, a polyspirofluorene, a substituted polyvinylidenylphenylene, a polycarbazole or a polystilbene, or copolymers thereof. Preferred dielectric materials (3) for use in the present invention preferably include materials having a low dielectric constant of 1.5 to 3.3 at 1000Hz, such as the cytops commercially available from Asahi Glass^TM809M。

The transistor device according to the present invention may also be a complementary organic tft (ctft) comprising a p-type semiconductor channel and an n-type semiconductor channel.

The method according to the invention is not limited to OFETs but can be used in the manufacture of any OE device comprising a charge injection layer, such as an OLED or OPV device. The skilled person can easily adapt or change the methods as described above and below to use for the manufacture of other OE devices.

For example, the method according to the invention may also be applied to electrodes in OPV devices, such as Bulk Heterojunction (BHJ) solar cells. The OPV device may be of any type known from the literature [ see, e.g., waldaf et al, appl.phys.lett.89,233517(2006) ].

A preferred OPV device according to the present invention comprises:

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

-a layer (also called "activation layer") comprising a hole transporting material and an electron transporting material, preferably selected from OSC materials, located between the low work function electrode and the high work function electrode; the active layer may be present, for example, as a bilayer or two distinct layers or a blend or mixture of p-type and n-type semiconductors, forming a Bulk Heterojunction (BHJ) (see, e.g., Coakley, k.m., and mcgehe, m.d. chem. mater.2004, 16, 4533),

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

an optional coating (e.g. LiF) on the side of the low work function electrode facing the activation layer to provide a resistive contact to electrons,

wherein at least one electrode, preferably a high work function electrode, is subjected to a method according to the invention as described above and below.

Another preferred OPV device according to the present invention is an inverted OPV device comprising:

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

-a layer (also called "activation layer") comprising a hole transporting material and an electron transporting material, preferably selected from OSC materials, located between the low work function electrode and the high work function electrode; the active layer may be present, for example, as a bilayer or two distinct layers or a blend or mixture of p-type and n-type semiconductors, forming a BHJ,

an optional conductive polymer layer, for example comprising a blend of PEDOT: PSS, between the active layer and the low work function electrode to provide a resistive contact of electrons,

an optional coating on the side of the high work function electrode facing the active layer (e.g. TiO)_x) To provide a resistive contact to the holes,

wherein at least one electrode, preferably a high work function electrode, is subjected to a method according to the invention as described above and below.

In the OPV device of the invention, it is therefore preferred that at least one electrode, preferably the high work function electrode, is covered on its surface facing the activation layer by a layer comprising a compound of formula I or comprising a formulation comprising a compound of formula I. Said layer is advantageously applied by the method according to the invention as described above and below.

OPV devices of the invention typically comprise a p-type (electron donor) semiconductor and an n-type (electron acceptor) semiconductor. The P-type semiconductor is for example a polymer such as poly (3-alkylthiophene) (P3 AT), preferably poly (3-hexylthiophene) (P3 HT), or alternatively another selected from the preferred polymeric and monomeric OSC materials as listed above. The n-type semiconductor may be an inorganic material such as zinc oxide or cadmium selenide, or an organic material such as a fullerene derivative, e.g. endomethylene C derived from methyl (6,6) -phenylbutyrate₆₀Fullerenes, also known as "PCBM" or "C₆₀PCBM ", such as those disclosed in G.Yu, J.Gao, J.C.Hummelen, F.Wudl, A.J.Heeger, Science1995, vol.270, 1789 and having the structure shown below, or such as C₇₀Structure-analogous compound of fullerene group (C)₇₀PCBM), or a polymer (see, e.g., Coakley, k.m., and mcgehe, m.d.chem.mater.2004, 16,4533）。

C₆₀PCBM

such preferred materials are polymers such as P3HT and another polymer selected from the group listed above, with C₆₀Or C₇₀A blend or mixture of fullerenes or modified fullerenes such as PCBM. Preferably, the ratio of polymer to fullerene is 2:1 to 1:2 by weight, more preferably 1.2:1 to 1:1.2 by weight, more preferably 1:1 by weight. For blended mixtures, an optional annealing step may be required to optimize the blend morphology and thus OPV device performance.

Preferably, the deposition of the respective functional layers, such as the OSC layer and the insulating layer, in the process as described above and below is performed using solution processing techniques. This can be done, for example, by applying a formulation, preferably a solution, comprising the OSC or the dielectric material, respectively, and further comprising one or more organic solvents onto the previously deposited electrode, followed by evaporation of the solvent. Preferred deposition techniques include, but are not limited to, dip coating, spin coating, ink jet printing, letterpress printing, screen printing, doctor blade coating, roll coating, reverse roll printing, offset printing, flexographic printing, screen printing, spray coating, brush coating, or pad printing. Highly preferred solution deposition techniques are spin coating, flexographic printing and inkjet printing.

In the OFET device according to the invention, the dielectric material used for the gate insulating layer is preferably an organic material. Preferably, the dielectric layer is solution coated, which allows for environmental processing, but may also be deposited by various vacuum deposition techniques. When patterning the dielectric material, it can perform the function of interlayer insulation or act as a gate insulator for OFETs. Preferred deposition techniques include, but are not limited to, dip coating, spin coating, ink jet printing, letterpress printing, screen printing, doctor blade coating, roll coating, reverse roll printing, offset printing, flexographic printing, screen printing, spray coating, brush coating, or pad printing. Ink jet printing is particularly preferred as it allows the production of high resolution layers and devices. Optionally, the dielectric material may be crosslinked or cured to achieve better resistance to solvents and/or structural integrity and/or to enable patterning capabilities (photolithography). Preferred gate insulators are those that provide a low dielectric constant interface to the organic semiconductor.

Suitable solvents are selected from the group consisting of hydrocarbon solvents, aromatic solvents, cycloaliphatic cyclic ethers, acetates, esters, lactones, ketones, amides, cyclic carbonates, or multicomponent mixtures of the foregoing. Examples of preferred solvents include cyclohexanone, mesitylene, xylene, 2-heptanone, toluene, tetrahydrofuran, MEK, MAK (2-heptanone), cyclohexanone, 4-methylanisole, butylphenyl ether and cyclohexylbenzene, with MAK, butylphenyl ether or cyclohexylbenzene being very preferred.

The total concentration of the respective functional material (OSC or gate dielectric material) in the formulation is preferably 0.1-30 wt.%, preferably 0.1-5 wt.%. In particular, organic ketone solvents having a high boiling point are advantageously used for solutions for inkjet and flexographic printing.

When spin coating is used as the deposition method, the OSC or dielectric material is rotated, for example at 1000-. After spin coating, the film may be heated at elevated temperatures to remove any residual volatile solvent.

For crosslinking, the crosslinkable dielectric material is preferably exposed to electron beam or electromagnetic (actinic) radiation, such as, for example, X-ray, UV or visible radiation, after deposition. For example, actinic radiation having a wavelength of from 50nm to 700nm, preferably 200-450 nm, most preferably 300-400 nm may be used. Suitable radiation doses are typically 25-3,000 mJ/cm². Suitable radiation sources include mercury, mercury/xenon, mercury/halogen and xenon lamps, argon or xenon laser sources, x-rays or electron beams. Exposure to actinic radiation will cause a crosslinking reaction in the crosslinkable groups of the dielectric material in the exposed areas. It is also possible for example to use light sources having wavelengths outside the absorption band of the crosslinkable group,and a radiation-sensitive sensitizer is added to the crosslinkable material.

The dielectric material is optionally annealed after exposure to radiation, for example at a temperature of 70 ℃ to 130 ℃, for example for a period of 1 to 30 minutes, preferably 1 to 10 minutes. An annealing step at an elevated temperature can be used to complete the crosslinking reaction induced by exposure of the crosslinkable groups of the dielectric material to actinic radiation.

All method steps described above and below can be performed using known techniques and standard equipment as described in the prior art and well known to the skilled person. For example, commercially available UV lamps and photomasks may be used in the light irradiation step, and the annealing step may be performed in an oven or on a hot plate.

In the electronic device according to the invention, the thickness of the functional layer (OSC layer or dielectric layer) is preferably from 1nm (in the case of a monolayer) to 10 μm, very preferably from 1nm to 1 μm, most preferably from 5nm to 500 nm.

Various substrates can be used for the manufacture of organic electronic devices, such as silicon wafers, glass or plastics, preferably plastic materials, examples including alkyd resins, allyl esters, benzocyclobutene, butadiene-styrene, cellulose acetate, epoxides, epoxy polymers, ethylene-chlorotrifluoroethylene, ethylene-tetrafluoroethylene, fiberglass reinforced plastics, fluorocarbon polymers, hexafluoropropylene vinylidene fluoride copolymers, high density polyethylene, parylene, polyamides, polyimides, polyaramids, polydimethylsiloxanes, polyethersulfones, polyethylene naphthalate, polyethylene terephthalate, polyketones, polymethylmethacrylate, polypropylene, polystyrene, polysulfone, polytetrafluoroethylene, polyurethane, polyvinylchloride, silicone rubber and silicone.

Preferred substrate materials are polyethylene terephthalate, polyimide and polyethylene naphthalate. The substrate may be any plastic material, metal or glass coated with the above materials. The substrate will preferably be uniform to ensure good pattern definition. The substrate may also be uniformly pre-aligned by extrusion, stretching, wiping, or by photochemical techniques, causing the organic semiconductor to orient to enhance carrier mobility. As used herein, plural forms of terms herein will be considered to include the singular form and vice versa, unless the context clearly dictates otherwise.

It will be appreciated that variations may be made to the embodiments of the invention described above while still falling within the scope of the invention. Each feature disclosed in this specification may, unless stated otherwise, be replaced by alternative features serving the same, equivalent or similar purpose. 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 the preferred embodiments, are inventive in their own right and not just as part of the embodiments of the invention. Independent protection may be sought for these features in addition to or in lieu of any of the presently claimed inventions.

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

The following parameters were used:

μ_LINis linear carrier mobility

μ_SATIs the saturation carrier mobility

W is the length of the drain and source electrodes (also known as the "channel width")

L is the distance between the drain and source electrodes (also known as the "channel length")

I_DIs source-drain current

C_OXIs the capacitance per unit area of the gate dielectric material

V_GIs a grid voltage (in V)

V_DSIs a source-drain voltage

Sqrt (ID) is the linear carrier mobility

Unless otherwise stated, specific values of all physical parameters such as dielectric constant (), carrier mobility (μ), solubility parameter () and viscosity (η), as given above and below, relate to a temperature of 20 ℃ (+/-1 ℃).

Example 1 OTFT with Cu S/D electrode subjected to two-step SAM treatment Process

Top gate OTFT devices were fabricated on glass as described below.

Substrate cleaning:

a1 "x 1" glass substrate (Corning XG 2000) was placed in a substrate holding box and filled with methanol and sonicated in an ultrasonic bath at 25 ℃ for 3 minutes.

The substrate was spin dried by placing it on a spin coater and spinning at 2000rpm for 20 s.

Source/drain (S/D) electrode preparation:

cu S/D electrodes were prepared by thermal evaporation of Cu through a shadow mask using an Edwards 306 evaporator. The active channel size is 50 μm/1000 μm length/width. The thickness of the electrode was 40nm and the evaporation rate was 0.1 nm/s.

Source/drain processing:

the glass substrate with the Cu S/D electrode was cleaned by soaking in 1% acetic acid for 5 minutes, then rinsed with water and spin dried on a spin coater. A solution of 1% of a compound of formula I11a (4, 5,6, 7-tetrafluoro-1H-benzotriazole, "F4 BTA") in Isopropanol (IPA) was then applied by soaking the substrate for 1 minute on a spin coater. After 1 minute the formulation was spun out and subsequently spin rinsed with IPA. The samples were then spin dried and annealed at 100 ℃ for 1 minute on a hot plate.

Coating of the OSC:

a commercially available OSC formulation Lisicon was applied by spin coating at 500rpm/10s followed by 2000rpm/60s(from Merck KGaA) followed by an annealing step on a hot plate at 100 ℃ for 1 min.

Dielectric coating:

use of807M Polymer (from Asahi Glass) as gate dielectric was spin coated at 500rpm/10s followed by 1700rpm/30s to give a film with 1.7nF/cm²The thickness of the capacitor is 1.1 μm.

Preparing a gate electrode:

cu gate electrodes were prepared by thermal evaporation of Cu through a shadow mask using an Edwards 306 evaporator. The thickness of the electrode was 40nm and the evaporation rate was 0.1 nm/s.

Transistor characterization:

the transistors were measured using an Agilent 4155C semiconductor analyzer connected to a probe station (probe station) equipped with a Karl Suss PH100 probe head. The transistors were measured as follows:

VD = -5V and from +20V to-60V and back scan VG in 1V steps (Linear mode)

VD = -60V and from +20V to-60V and back scan VG in 1V steps (saturation mode)

The mobility values were calculated using the following formula:

linear mode:

a saturation mode:

fig. 3 shows the transfer characteristics of the transistor obtained according to the method described above. It can be seen that the application of the treatment with 4FBTA to the copper electrode enables carrier injection and the transistor exhibits characteristics typical for the S1200 Lisicon formulation.

Linear mobility mu_LINSaturation mobility [ mu ]_SATAnd the value of the on-off ratio is given below:

linear mobility: 1.55cm²Vs, saturation mobility: 1.45cm²Vs, and on-off ratio: 10⁴

Example 2 OTFT with Cu S/D electrode subjected to Single step SAM treatment Process

A top gate OTFT device was prepared on glass and characterized as described in example 1, except that the step "source/drain processing" was performed in a single step as described below.

Source/drain processing:

a glass substrate with a Cu electrode was treated with a formulation comprising 1% acetic acid mixed with 1% compound of formula I11a (F4 BTA) in a 1:1 volume ratio for 1 minute. The substrate was then rinsed with water and IPA and spin dried on a spin coater.

Fig. 4 shows transfer characteristics of a transistor obtained by the method according to example 2. It can be seen that the application of a single step process to the copper electrode also enables carrier injection, and the transistor is for S1200The formulations exhibit typical characteristics.

Linear mobility mu_LINSaturation mobility [ mu ]_SATAnd the values of the on-off ratio are given below:

linear mobility: 1.5cm²S, saturation mobility: 0.75cm²Vs, and on-off ratio: 10³

Example 3 OTFT with Cu S/D electrode subjected to two-step SAM treatment Process

Top gate OTFT devices were prepared on glass and characterized as described in example 1, except that the step "source/drain processing" was performed as described below.

Source/drain processing:

the glass substrate with the Cu S/D electrode was cleaned by soaking in 1% acetic acid for 5 minutes, then rinsed with water and spin dried on a spin coater. Then 0.2% of R, where R is dissolved in isopropyl alcohol (IPA), is applied by soaking the substrate on a spin coater for 1 minute^fIs CF₃And R^xIs NH₂A solution of the compound of formula I15f (5- (trifluoromethyl) -1H-indazol-3-amine). After 1 minute the formulation was spun out and subsequently spin rinsed with IPA. The samples were then spin dried and annealed at 100 ℃ for 1 minute on a hot plate.

Fig. 5 shows the transfer characteristics of the transistor obtained by the method according to example 3. It can be seen that applying treatment with 5- (trifluoromethyl) -1H-indazol-3-amine to copper electrodes enables carrier injection, and that the transistor is for S1200The formulations exhibit typical characteristics.

Linear mobility mu_LINSaturation mobility [ mu ]_SATAnd the values of the on-off ratio are given below:

linear mobility: 1.7cm²S, saturation mobility: 1.25cm²Vs, and on-off ratio: 10⁴

Comparative example 1 OTFT having Cu S/D electrode without SAM treatment method

Top gate OTFT devices were prepared on glass and characterized as described in example 1, except that the step "source/drain processing" was performed as described below.

Source/drain processing:

the glass substrate with the Cu electrode was cleaned by soaking in 1% acetic acid for 5 minutes, then rinsed with water and spin-dried on a spin coater.

FIG. 6 shows the transition of a transistor obtained by the method according to comparative example 1And (4) moving the features. It can be seen that the transistor exhibits poor performance and low on-current values, which for S1200Formulations are not typical. This indicates that the untreated copper electrode cannot effectively inject carriers into the OSC layer.

Linear mobility mu_LINSaturation mobility [ mu ]_SATAnd the values of the on-off ratio are given below:

linear mobility: 0.28cm²S, saturation mobility: 0.1cm²Vs, and on-off ratio: 10³。

Claims (14)

1. A method comprising the steps of:

providing one or more electrodes comprising a metal or metal oxide in an electronic device, and

depositing a layer comprising a compound of formula I on the surface of the electrode, and

depositing an organic semiconductor on the surface of the electrode covered by the layer comprising the compound of formula I, or in the region between two or more of the electrodes,

wherein

X¹、X²、X³Independently of one another, from the group consisting of-N (H) -, -N ═ N-, -C (R)^x)＝、＝C(R^x) -and-S-, wherein X¹、X²And X³Is different from-C (R)^x) ═ C (R)^x)-，

R^xH, NH being identical or different on each occurrence₂Or a linear or branched alkyl group having 1 to 15C atoms, wherein one or more non-adjacent C atoms are optionally substituted by-O-, -NR-⁰-、-CO-、-CO-O-、-O-CO-、O-CO-O-、-CR⁰＝CR⁰⁰-or-C.ident.C-and wherein one or more H atoms are optionally replaced by F, Cl, Br, I or CN,

R¹and R²Independently of one another, F, Cl, P-Sp-or a linear or branched alkyl radical having 1 to 15C atoms, where one or more nonadjacent C atoms are optionally interrupted by-O-, -NR-⁰-、-CO-、-CO-O-、-O-CO-、-O-CO-O-、-CR⁰＝CR⁰⁰-or-C ≡ C-and wherein one or more H atoms are optionally replaced by F, Cl, Br, I or CN, or represent aryl, heteroaryl, aryloxy, heteroaryloxy, arylcarbonyl, heteroarylcarbonyl, arylcarbonyloxy, heteroarylcarbonyloxy, aryloxycarbonyl or heteroaryloxycarbonyl having 2 to 30C atoms, unsubstituted or substituted by one or more non-aromatic groups R, or R¹And R²Together with each other and with the 5-membered heterocyclic ring to which they are attached, form an aromatic or heteroaromatic ring which contains 5 to 7 ring atoms and is unsubstituted or substituted by 1,2, 3,4 or 5 radicals R,

R⁰and R⁰⁰Independently of one another, H or an optionally substituted carbyl or hydrocarbyl radical optionally containing one or more heteroatoms,

r is in each case, identically or differently, H, P-Sp-, halogen, -CN, -NC, -NCO, -NCS, -OCN, -SCN, -C (═ O) NR⁰R⁰⁰、-C(＝O)X⁰、-C(＝O)R⁰、-NH₂、-NR⁰R⁰⁰、-SR⁰、-SO₃H、-SO₂R⁰、-OH、-NO₂、-CF₃、-SF₅Optionally substituted silyl, optionally substituted carbyl or hydrocarbyl having 1 to 40C atoms optionally substituted and optionally containing one or more heteroatoms,

p is a polymerizable or crosslinkable group,

sp is a spacer group or a single bond,

X⁰is a halogen.

2. A process according to claim 1, characterized in that in the compound of formula I, R is¹And R²Together with each other and with the 5-membered heterocyclic ring to which they are attached, form a phenyl ring in which one or two CH groups are optionally replaced by N, and in which the ring is unsubstituted or substituted by 1,2, 3 or 4 groups R.

3. The process according to claim 1 or 2, characterized in that in the compound of formula I, R is¹And R²Together with the 5-membered heterocyclic ring to which they are attached, form a benzene, pyridine or pyrimidine ring which is unsubstituted or substituted by 1,2, 3 or 4 non-aromatic groups R.

4. Method according to one or more of claims 1 to 3, characterized in that the compound of formula I is selected from the group consisting of formula I1

Wherein

X¹is-N (H) -, -C (R)^x) either-or-S-,

X²is-N ═, -N (H) -, -C (R)^x) either-or-S-,

X³is-N ═ or-N (H) -,

r is 0,1, 2,3 or 4,

and R is^xAnd R has the meaning given in claim 1The meanings given.

5. The process according to one or more of claims 1 to 4, characterized in that the compound of formula I is selected from the following formulae

Wherein R is^xR and R are as defined in claim 4.

6. Process according to one or more of claims 1 to 5, characterized in that in the formulae I, I1 and I11-I15, R^xIs H, NH₂And R represents, identically or differently on each occurrence, F or C₁-C₁₅A perfluoroalkyl group.

7. The process according to one or more of claims 1 to 5, characterized in that in the formulae I, I1 and I11-I15 at least one radical R^xOr R represents P-Sp-, wherein P and Sp are as defined in claim 1.

8. The process according to one or more of claims 1 to 7, characterized in that the compound of formula I is selected from the following formulae

Wherein R is^fIs a linear or branched perfluoroalkyl radical having 1 to 15C atoms, and alkylene and R^xAs defined in claim 5,6 or 7.

9. Method according to one or more of claims 1 to 8, characterized in that it comprises the following steps:

a) the source and drain electrodes are deposited on the substrate or on the gate insulating layer,

b) the source and drain electrodes are optionally cleaned,

c) depositing a layer of a compound of formula I or a formulation comprising a compound of formula I and optionally one or more solvents in the region between the source and drain electrodes and optionally on the surface of the source and drain electrodes, optionally removing any solvent present and optionally annealing the layer of a compound of formula I,

d) depositing a layer of an Organic Semiconductor (OSC) or a formulation comprising an OSC on the source and drain electrodes and on the layer comprising the compound of formula I, optionally removing the solvent still present and optionally annealing the OSC layer,

wherein optionally steps b) and c) are combined into a single step.

10. Method according to one or more of claims 1 to 9, characterized in that it comprises the following steps:

a) a source electrode and a drain electrode are deposited on the substrate,

b) the source and drain electrodes are optionally cleaned,

c) depositing a layer of a compound of formula I or a formulation comprising a compound of formula I and optionally one or more solvents in the region between the source and drain electrodes and optionally on the surface of the source and drain electrodes, optionally removing any solvent present and optionally annealing the layer of a compound of formula I,

d) depositing a layer of an Organic Semiconductor (OSC) or a formulation comprising the OSC on the source and drain electrodes and on the layer comprising the compound of formula I, optionally removing the solvent still present, and optionally annealing the OSC layer,

e) a gate insulating layer is deposited on the OSC layer,

f) a gate electrode is deposited on the gate insulating layer,

g) a passivation layer is optionally deposited on the gate electrode,

wherein optionally steps b) and c) are combined into a single step.

11. Formulations comprising one or more compounds of the formula I as defined in one or more of claims 1 to 8 and further comprising one or more organic or inorganic acids.

12. Organic electronic device obtainable by a process according to at least one of claims 1 to 10.

13. The organic electronic device according to claim 12, characterized in that it is selected from the group consisting of Organic Field Effect Transistors (OFETs), Organic Thin Film Transistors (OTFTs), Integrated Circuit (IC) components, Radio Frequency Identification (RFID) tags, Organic Light Emitting Diodes (OLEDs), electroluminescent displays, flat panel displays, backlights, photodetectors, sensors, logic circuits, memory elements, capacitors, Organic Photovoltaic (OPV) cells, charge injection layers, schottky diodes, planarising layers, antistatic films, conductive substrates or patterns, photoconductors, photoreceptors, electrophotographic devices and xerographic devices.

14. Electronic device according to claim 12 or 13, characterized in that it is a top-gate or bottom-gate OFET.