DE102004010811B4 - Composition useful in article of manufacture e.g. electroluminescent arrangement comprises polythiophenes; polymer that is different from polythiophene; and polymer selected from partially fluorinated polymer and/or perfluorinated polymer - Google Patents

Abstract

A composition (C1) comprises at least one polythiophene (a) containing recurring units; at least one polymer (b) that is different from (a) and which contains sulfonate salt or carboxylate salt; and at least one polymer (c) that is different than (a) and (b) and which contains sulfonate salt or carboxylate salt and is selected from partially fluorinated polymer and/or perfluorinated polymer. - A composition (C1) comprises at least one polythiophene (a) containing recurring units of formula (I); at least one polymer (b) that is different from (a) and which contains SO3-M+ or COO-M+; and at least one polymer (c) that is different than (a) and (b) and which contains SO3-M+ or COO-M+ and is selected from partially fluorinated polymer and/or perfluorinated polymer. - A = optionally substituted 1-5C alkylene; - R = linear or branched 1-18C alkyl, 5-12C cycloalkyl, 6-14C aryl, 7-18C aralkyl, 1-4C hydroxyalkyl or hydroxyl; - x = 0 - 8;and - M = H, Li, Na, K, Rb, Cs or NH4. - An INDEPENDENT CLAIM is included for an electroluminescent (EL) arrangement comprising either at least one layer selected from hole-injecting layer and hole-transporting layer where hole-injecting layer and hole-transporting layers each containing (C1); or a substrate, at least two electrode layers, at least one emitter layer and at least one hole-injecting layer where at least one electrode layer abuts the substrate, the emitter layer is interposed between two electrode layers and at least one hole-injecting layer is interposed between one of the electrode layers and the emitter layer and further the hole-injecting layer containing (C1).

Description

The The invention relates to formulations containing polythiophenes and others Polymers and their use.

A electroluminescent device (EL device) is characterized by that when applying an electrical voltage under current flow Emit light. Such arrangements are called "light emitting diodes" (LEDs = "light emitting diodes ") known for a long time. The emission of light comes about as a result, that positive charges (holes, "holes") and negative charges (Electrons, "electrons") under emission of light recombine.

The common in the art LEDs are all predominantly Part of inorganic semiconductor materials. For several years However, EL devices are known whose essential components organic materials are.

These Organic EL devices typically contain one or more Layers of organic charge transport compounds.

Of the principal layer structure of an EL device is as follows:

1

Carrier, substrate

2

base electrode

3

Hole-injecting layer

4

Hole-transporting layer

5

Emitter layer

6

Electron-transporting layer

7

Electron-injecting layer

8th

top electrode

9

contacts

10

Serving, encapsulation

This Construction is the most detailed case and can be simplified be omitted by allowing individual layers, so that one Layer performs several tasks. In the simplest case, an EL arrangement consists of two electrodes, between which there is an organic layer, all functions - inclusive that of the emission of light - fulfilled.

It But it has been shown in practice that to increase the Luminous electron- and / or hole-injecting layers in the electroluminescent structures are particularly advantageous.

From the EP 686 662 A2 It is known to use special mixtures of conductive organic polymeric conductors such as poly (3,4-ethylenedioxythiophene) and, for example, polyhydroxy compounds or lactams as electrode in electroluminescent displays. However, it has been found in practice that these electrodes have an insufficient conductivity, especially for large-area displays. For small displays (light area <1 cm ² ), the conductivity is sufficient.

From the DE 196 27 071 A1 It is known to use polymeric organic conductors, for example poly (3,4-ethylenedioxythiophene), as hole-injecting layers. As a result, the luminosity of the electroluminescent displays compared to structures without the use of polymeric organic interlayers can be significantly increased. By reducing the particle size of the poly (3,4-alkylenedioxythiophene) dispersions, it is possible to adjust the conductivity in a targeted manner. This makes it possible to prevent electrical crosstalk of adjacent address lines (crosstalk), in particular in passive matrix displays ( EP 1 227 529 A2 ).

The Lifespan of these displays is but for many practical applications still not enough.

It There was therefore a continuing need to produce EL devices which in addition to a high luminosity (Light intensity) a higher one Have life as known EL arrangements.

From the German patent application DE 101 03 416 A1 EL devices are known which contain conductive polymers as auxiliary layers, in particular 3,4-polyalkylenedioxythiophenes, and also corresponding dispersions which contain polystyrenesulphonic acid as the polyanion and are suitable for the production of electroluminescent arrangements. However, the lifetime of the EL devices that can be produced with these dispersions is not yet sufficient for practical applications since, after prolonged use, the luminescence intensity of these arrangements is based on DE 101 03 416 A1 markedly reduced. Furthermore, there is an EL arrangement from the DE 198 41 803 A1 has become known, which also describes an electroluminescent device containing as a hole-injecting layer, a polymeric organic conductor, which may include, inter alia, polythiophene. The doctrine of DE 198 41 803 A1 However, does not go beyond the aforementioned prior art, also provides no evidence how the luminescence activity can be further improved by means of suitable polymer dispersions.

The It is an object of the present invention to provide suitable Find materials for the preparation of such EL devices and provide. Another task was to make these Materials to produce such EL devices.

Surprised was found containing previously unknown formulations optionally substituted polythiophenes or optionally substituted ones Polyanilines or polypyrroles and other polymers are excellent for the production of hole-injecting layers for EL arrangements and the obtained EL arrangements significantly higher Have lifetimes as known EL arrangements.

worin
A für einen gegebenenfalls substituierten C₁-C₅-Alkylenrest, bevorzugt für einen gegebenenfalls substituierten Ethylen- oder Propylenrest, besonders bevorzugt für einen 1,2-Ethandiyl-Rest steht,
R für einen linearen oder verzweigten C₁-C₁₈-Alkylrest, bevorzugt für einen linearen oder verzweigten C₁-C₁₄-Alkylrest, besonders bevorzugt für einen Methyl- oder Ethylrest, einen C₅-C₁₂-Cycloalkylrest, einen C₆-C₁₄-Arylrest, einen C₇-C₁₈-Aralkylrest, einen C₁-C₄-Hydroxyalkylrest oder einen Hydroxylrest steht,
x für eine ganze Zahl von 0 bis 8, bevorzugt für 0, 1 oder 2, besonders bevorzugt für 0 oder 1 steht und
für den Fall, dass mehrere Reste R an A gebunden sind, diese gleich oder unterschiedlich sein können,
wenigstens ein SO₃ ^–M⁺- oder COO^–M⁺-Gruppen enthaltendes Polymer, wobei M⁺ für H⁺, Li⁺, Na⁺, K⁺, Rb⁺, Cs⁺ oder NH₄ ⁺, bevorzugt für H⁺, Na⁺ oder K⁺ steht, und
wenigstens ein SO₃ ^–M⁺- oder COO^–M⁺-Gruppen enthaltendes, teilfluoriertes oder perfluoriertes Polymer, wobei M⁺ für H⁺, Li⁺, Na⁺, K⁺, Rb⁺, Cs⁺ oder NH₄ ⁺, bevorzugt für H⁺, Na⁺ oder K⁺ steht.The present invention therefore provides formulations comprising at least one polythiophene containing repeating units of the general formula (I),

wherein
A represents an optionally substituted C ₁ -C ₅ -alkylene radical, preferably an optionally substituted ethylene or propylene radical, particularly preferably a 1,2-ethanediyl radical,
R is a linear or branched C ₁ -C ₁₈ -alkyl radical, preferably a linear or branched C ₁ -C ₁₄ -alkyl radical, particularly preferably a methyl or ethyl radical, a C ₅ -C ₁₂ -cycloalkyl radical, a C ₆ - C ₁₄ -aryl radical, a C ₇ -C ₁₈ -aralkyl radical, a C ₁ -C ₄ -hydroxyalkyl radical or a hydroxyl radical,
x is an integer from 0 to 8, preferably 0, 1 or 2, more preferably 0 or 1, and
in the case where several radicals R are attached to A, they may be the same or different,
at least one polymer containing SO ₃ ^- M ⁺ or COO ^- M ⁺ groups, where M ^{+ is} H ⁺ , Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , Cs ⁺ or NH ₄ ⁺ , preferably H ⁺ , Na ⁺ or K ⁺ stands, and
at least one partially fluorinated or perfluorinated polymer containing SO ₃ ^- M ⁺ or COO ^- M ⁺ groups, where M ^{+ is} H ⁺ , Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , Cs ⁺ or NH ₄ ⁺ , preferably H ⁺ , Na ⁺ or K ⁺ stands.

The general formula (I) is understood to mean that the substituent R x times to the alkylene radical A may be bound.

worin
R und x die oben genannte Bedeutung haben.In preferred embodiments of the formulation according to the invention, at least one polythiophene containing repeating units of the general formula (I) is one containing repeating units of the general formula (Ia),

wherein
R and x have the abovementioned meaning.

In very particularly preferred formulations as described above x for 0 or 1. For the If x is 1, R is more preferably methyl or hydroxymethyl.

In further preferred embodiments of the formulation according to the invention, at least one polythiophene containing recurring units of the general formula (I) is one containing recurring units of the general formula (Iaa)

Under the prefix Poly- is to be understood within the scope of the invention that more than one same or different repeating unit in the polymer or Polythiophene is included. The polythiophenes contain total n repeating units of the general formula (I), where n is a integer from 2 to 2000, preferably 2 to 100, may be. The recurring Units of the general formula (I) can be used within a polythiophene each same or different. Preference is given to polythiophenes containing in each case identical repeating units of the general Formula (I).

Under Recurring units are within the scope of the invention units of the general formulas (I), (Ia) or (Iaa), hereinafter referred to as recurring Units of the general formula (I), to understand independently of whether they are contained once or several times in polythiophene. That Units of general formula (I) are also considered to be recurring Units if they contain only once in polythiophene are.

Formulations according to the invention can also be those which in addition to at least one of the previously described Polythiophenes containing recurring units of the general Formula (I) further conductive Contain polymers such as polyanilines or polypyrroles At the end groups, the polythiophenes preferably carry H.

The Polythiophenes contain a total of n repeating units of general formula (I), where n is an integer from 2 to 1000, preferably 3 to 100, more preferably 4 to 15.

C ₁ -C ₅ -alkylene radicals A are in the context of the invention methylene, ethylene, n-propylene, n-butylene or n-pentylene. C ₁ -C ₁₈ -alkyl in the context of the invention is linear or branched C ₁ -C ₁₈ -alkyl radicals, for example methyl, ethyl, n- or isopropyl, n-, iso-, sec- or tert-butyl, n -Pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylpropyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, n-hexyl, n-heptyl, n-octyl, 2 Ethylhexyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-hexadecyl or n-octadecyl, C ₅ -C ₁₂ cycloalkyl for C ₅ -C ₁₂ cycloalkyl radicals such as cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl or cyclodecyl, C ₅ -C ₁₄ -aryl for C ₅ -C ₁₄ -aryl radicals such as phenyl or naphthyl, and C ₇ -C ₁₈ -aralkyl for C ₇ -C ₁₈ - Aralkyl radicals such as benzyl, o-, m-, p-tolyl, 2,3-, 2,4-, 2,5-, 2,6-, 3,4-, 3,5-xylyl or mesityl. The preceding list serves to exemplify the invention and is not to be considered as exhaustive.

The preparation of the above-described polythiophenes containing recurring units of the general formula (I) is in principle in EP 440 957 A2 described.

The polymerization of the corresponding monomeric compounds is carried out with suitable oxidizing agents in suitable solvents. Examples of suitable oxidizing agents are iron (III) salts, in particular FeCl ₃ and iron (III) salts of aromatic and aliphatic sulfonic acids, H ₂ O ₂ , K ₂ Cr ₂ O ₇ , K ₂ S ₂ O ₈ , Na ₂ S ₂ O ₈ , KMnO ₄ , alkali metal perborates and alkali or ammonium persulfates or mixtures of these oxidizing agents. Other suitable oxidizing agents are described, for example, in Handbook of Conducting Polymers (Ed., Skotheim, TA), Marcel Dekker: New York, 1986, Vol. 1, 46-57. Particularly preferred oxidizing agents are FeCl ₃ , Na ₂ S ₂ O ₈ and K ₂ S ₂ O ₈ or mixtures thereof. The polymerization is preferably carried out at a reaction temperature of -20 to 100 ° C. Particularly preferred are reaction temperatures of 20 to 100 ° C. Optionally, the reaction solution is subsequently treated with at least one ion exchanger.

suitable solvent are e.g. polar solvents such as water, alcohols such as methanol, ethanol, 2-propanol, n-propanol, n-butanol, diacetone alcohol, ethylene glycol, glycerin or mixtures of these. Also suitable are aliphatic Ketones such as acetone and methyl ethyl ketone, aliphatic nitriles such as Acetonitrile, aliphatic and cyclic amides such as N, N-dimethylacetamide, N, N-dimethylformamide (DMF) and 1-methyl-2-pyrrolidone (NMP), ether such as tetrahydrofuran (THF) and sulfoxides such as dimethyl sulfoxide (DMSO) or mixtures of these with each other or with the foregoing listed Solvents.

The corresponding monomeric compounds for the preparation of polythiophenes containing recurring units of the general formula (I) known. Their production is, for example, by the implementation of Alkali salts of 3,4-dihydroxythiophene-2,5-dicarboxylic acid esters with the corresponding alkylene dihalides and subsequent decarboxylation the free 3,4- (alkylenedioxy) thiophene-2,5-dicarboxylic acids possible (see z. Tetrahedron 1967, 23, 2437-2441 and J. Am. Chem. Soc. 1945, 67, 2217-2218).

The resulting polythiophenes are very good in the polar solvents or solvent mixtures soluble or dispersible.

The formulations according to the invention contain, in addition to at least one partially fluorinated or perfluorinated, at least one further polymer containing SO ₃ ^- M ⁺ or COO ^- M ⁺ groups. Polymers containing SO ₃ ^- M ⁺ or COO ^- M ⁺ groups which are suitable for the purposes of the invention are preferably those which do not contain a completely conjugated main chain, hereinafter also referred to as non-conjugated for short. Examples of suitable polymers containing SO ₃ ^- M ⁺ or COO ^- M ⁺ groups are polymeric carboxylic acids, such as polyacrylic acids, polymethacrylic acid or polymaleic acids, or polymeric sulfonic acids, such as polystyrenesulfonic acids and polyvinylsulfonic acids. Also suitable are copolymers of vinylcarboxylic and vinylsulfonic acids with other polymerizable monomers, such as acrylic acid esters and styrene. Particularly suitable are polystyrene sulfonic acid, poly (styrenesulfonic acid-co-maleic acid) or poly (vinyl sulfonic acid). Very particularly suitable formulations according to the invention are characterized in that they contain polystyrenesulfonic acid (PSS) as at least one polymer containing SO ₃ ^- M ⁺ or COO ^- M ⁺ groups.

Prefers These polymers are in polar solvents such as water, alcohols such as methanol, ethanol, 2-propanol, n-propanol, n-butanol, diacetone alcohol, ethylene glycol, glycerol, aliphatic Ketones such as acetone and methyl ethyl ketone, aliphatic nitriles such as acetonitrile, aliphatic and cyclic amides such as N, N-dimethylacetamide, N, N-dimethylformamide (DMF) and 1-methyl-2-pyrrolidone (NMP), ethers such as tetrahydrofuran (THF) and sulfoxides such as dimethyl sulfoxide (DMSO) or mixtures containing these, preferably in water, alcohols such as methanol, ethanol, 2-propanol, n-propanol and n-butanol or Mixtures of these soluble or dispersible.

worin R_f für einen Rest mit wenigstens einer, bevorzugt 1 bis 30 wiederkehrenden Einheiten) der Formel (II-c)

steht, enthalten. Solche perfluorierten Polymere sind beispielsweise die kommerziell unter dem Handelsnamen Nafion^® oder in gelöster Form unter dem Handelsnamen Liquion^® erhältlichen Polymere.Particularly suitable formulations as described above are characterized in that they contain as at least one SO ₃ ^- M ⁺ - or COO ^- (b II) containing M ⁺ groups partially fluorinated or perfluorinated, for example those containing repeating units of the formulas (II-a) and .

wherein R _{f is} a radical having at least one, preferably 1 to 30 repeating units) of the formula (II-c)

is included. Such perfluorinated polymers are for example the polymers commercially available under the trade name Nafion ^® or in dissolved form under the trade name LIQUION ^®.

In particularly preferred embodiments, the formulation of the invention contains as at least one SO ₃ ^- M ⁺ - or COO ^- M ⁺ groups containing polymer Nafion ^®.

Particularly preferred are formulations which as SO ₃ ^- M ⁺ - or COO ^- M ⁺ groups containing polymer polystyrene sulfonic acid (PSS) and as SO ₃ ^- M ⁺ - or COO ^- M ⁺ groups containing partially fluorinated or perfluorinated polymer Nafion ^® included.

The Molecular weight of the polyacids is preferably 1 000 to 2 000 000, more preferably 2 000 to 500 000. The polyacids or their alkali salts are commercially available, e.g. Polystyrenesulfonic acids and polyacrylic acids, or else can be prepared by known processes (see, for example, Houben Weyl, Methoden der organischen Chemie, Vol. E 20 Macromolecular Substances, Part 2, (1987), p 1141 u.f.).

The formulations according to the invention very particularly preferably comprise the polythiophene (s) containing recurring units of the general formula (I) and the polymer (s) containing the SO ₃ ^- M ⁺ or COO ^- M ⁺ groups in one Weight ratio of polythiophene (s) to polymer (s) containing SO ₃ ^- M ⁺ or COO ^- M ⁺ groups of 1: 2 (1: 2) to 1: 25 (1: 25), preferably 1 to 2 (1: 2) to 1 to 10 (1:10).

With very particular preference, the formulations according to the invention contain the polythiophene (s) containing recurring units of the general formula (I) and the or the SO ₃ ^- M ⁺ or COO ^- M ⁺ groups-containing, partially fluorinated or perfluorinated polymer (e) in a weight ratio of polythiophene (s) to SO ₃ ^- M ⁺ or COO ^- M ⁺ group containing, partially fluorinated or perfluorinated polymer (s) of 1 to 1 (1: 1) 1) to 1 to 15 (1:15), preferably from 1 to 2 (1: 2) to 1 to 10 (1:10).

Any combination of the two above-described weight ratios of polythiophene (s) to polymer (s) containing SO ₃ ^- M ⁺ or COO ^- M ⁺ groups and polythiophene (s) to SO ₃ ^- M ⁺ or COO ^- M ⁺ -groups containing, partially fluorinated or perfluorinated polymer (s) may be realized in the formulations according to the invention and are hereby disclosed as disclosed.

Furthermore, the formulations according to the invention may contain at least one polar diluent (polar solvent). In the context of the invention, polar diluents (polar solvents) are to be understood as meaning diluents having a solubility parameter 6 of 16 MPa ^1/2 and greater, preferably 19 MPa ^1/2 and greater. The measurement of solubility parameters usually takes place at standard temperature (20 ° C). For measurement and calculation of solubility parameters, see J. Brandrup et al., Polymer Handbook, 4 ^th Ed., 1999, VII / 675-VII / 688. Solubility parameters are tabulated, eg in J. Brandrup et al., Polymer Handbook, 4 ^th Ed., 1999, VII / 688-VII / 697. Preferred polar diluents are water, alcohols such as methanol, ethanol, 2-propanol, n-propanol, n-butanol, diacetone alcohol, ethylene glycol, glycerol, aliphatic ketones such as acetone and methyl ethyl ketone, aliphatic nitriles such as acetonitrile, aliphatic and cyclic amides such as N, N Dimethylacetamide, N, N-dimethylformamide (DMF) and 1-methyl-2-pyrrolidone (NMP), ethers such as tetrahydrofuran (THF) and sulfoxides such as dimethylsulfoxide (DMSO) or mixtures containing these. Particularly preferred polar diluents are water, alcohols or mixtures containing them, very particular preference is given to water, methanol, ethanol, n-propanol, 2-propanol or n- Such formulations according to the invention containing at least one polar diluent preferably contain 99.99 to 80% by weight , particularly preferably 99.8 to 95% by weight of polar diluent and have a solids content of 0.01 to 20% by weight, particularly preferably 0.2 to 5% by weight, ie contain in total 0, 01 to 20 wt .-%, particularly preferably 0.2 to 5 wt .-% polythiophene (s), SO ₃ ^- M ⁺ - or COO ^- M ⁺ groups containing) polymer (s) and optionally further components contained, such as For example, binders, crosslinking agents and / or surfactants, in dissolved and / or dispersed form.

The viscosity at 20 ° C of formulations according to the invention containing at least one polar diluent is between the viscosity of the diluent and 200 mPas, preferably <100 mPas.

to Setting the desired Solids content and the required viscosity may be the desired formulations Amount of diluent by distillation, preferably in vacuo, or by other methods, e.g. Ultrafiltration, to be removed.

In addition, organic, polymeric binders and / or organic, low molecular weight crosslinking agents or surfactants can be added to the formulations according to the invention. Corresponding binders are for example in EP 564 911 A2 described. Examples are here polyvinylcarbazole, silanes such as Silquest ^® A187 (Fa. OSi specialties) or surfactants such as the fluorosurfactant FT listed 248 (Bayer AG).

The formulations preferably contain only small amounts of ionic impurities in the limits as in EP 991 303 A2 are described. Preferably, the formulations contain less than 1000 ppm of ionic impurities.

The formulations according to the invention can be prepared in a simple manner. For example, it is possible to use an already finished mixture containing at least one polymer containing SO ₃ ^- M ⁺ or COO ^- M ⁺ groups and at least one polythiophene having at least one partially fluorinated or perfluorinated, SO ₃ ^- M ⁺ or COO ^- M ⁺ . To mix groups containing polymer and this mixture optionally with at least one diluent to put, preferably in at least one diluent to dissolve or disperse completely or partially. It is also possible to add at least one previously prepared mixture comprising a polymer containing SO ₃ ^{- +} or COO ^- M ⁺ groups and at least one polythiophene beforehand with at least one diluent, preferably completely or partially dissolving it in at least one diluent or to disperse, dissolve or disperse at least one partially fluorinated or perfluorinated polymer containing SO ₃ ^- M ⁺ or COO ^- M ⁺ groups in a diluent and then to mix the solutions and / or dispersions).

Possibly can then from this mixture or the diluent be completely or partially removed, e.g. by distillation or other procedures.

Surprised the formulations according to the invention are suitable excellent for the production of hole-injecting or hole-transporting layers in EL devices, organic solar cells, organic laser diodes, organic thin film transistors or organic field effect transistors, for the production of electrodes or more electrically conductive Coatings.

Therefore is also an object of the present invention, the use the formulations according to the invention for producing hole-injecting layers in EL devices, for Production of electrodes or electrically conductive coatings.

Especially EL devices with a hole-injecting layer containing a inventive formulation are characterized by a high luminosity (luminous intensity) and a significantly higher Lifetime than known EL arrangements.

Prefers are these EL devices containing at least two electrodes, of which, where appropriate, at least one to an optionally transparent one Substrate is applied, at least one emitter layer between the two electrodes and at least one hole-injecting layer between one of the two electrodes and the emitter layer, thereby in that the hole-injecting layer is a formulation according to the invention contains.

• a) Metalloxide, z.B. Indium-Zinn-Oxid (ITO), Zinnoxid (NESA), dotiertes Zinnoxid, dotiertes Zinkoxid etc.,
• b) semi-transparente Metallfilme, z.B. Au, Pt, Ag, Cu etc.,
• c) semi-transparente, leitfähige Polymere, z.B. Polythiophene, Polyaniline, Polypyrrole etc.

geeignet.In the manufacture of many large-area EL devices, for example large-area electroluminescent display elements, it is advantageous if at least one of the current-supplying electrodes consists of a transparent and conductive material. As such, transparent and conductive electrode materials are, for example

• a) metal oxides, eg indium tin oxide (ITO), tin oxide (NESA), doped tin oxide, doped zinc oxide etc.,
• b) semi-transparent metal films, eg Au, Pt, Ag, Cu etc.
• c) semi-transparent, conductive polymers, eg polythiophenes, polyanilines, polypyrroles etc.

suitable.

at an electrode not made of any of the foregoing transparent and conductive materials is, it is preferably a metal electrode, in particular around a metal cathode.

suitable Materials for Metal cathodes are the ones for Electro-optical structures common and known to those skilled in the art. As the metal cathode are preferably such from metals with low work function such as Mg, Ca, Ba or metal salts like LiF into consideration.

When optionally transparent substrate are suitable, for example Glass, thin glass (flexible glass) or plastics, preferably plastic films.

Especially suitable plastics are: polycarbonates, polyesters such as e.g. PET and PEN (polyethylene terephthalate or polyethylene naphthalene dicarboxylate), Copolycarbonates, polyacrylate, polysulfone, polyethersulfone (PES), Polyimide, polyethylene, polypropylene or cyclic polyolefins or cyclic olefin copolymers (COC), hydrogenated styrene polymers or hydrogenated styrene copolymers.

Suitable polymer substrates may be from Bayer AG (Makrofol ^®), for example, films such as polyester films, PES films from Sumitomo or polycarbonate films.

There may be a primer layer between the substrate and the electrode. Suitable adhesion promoters are, for example, silanes. Preferred are epoxy silanes, such as 3-glycidoxypropyltrimethoxysilane (Silquest ^® A187, Fa. OSi Specialties). Other adhesion promoters with hydrophilic surface properties can also be used. For example, a thin layer of PEDT: PSS is described as a suitable adhesion promoter for PEDT (Hohnholz et al., Chem. Commun. 2001, 2444-2445).

At least one emitter material is contained in the emitter layer of the EL device according to the invention. Suitable emitter materials are those commonly used in electro-optical structures and known to the person skilled in the art. Preferred emitter materials are conjugated polymers such as polyphenylenevinylenes and / or polyfluorenes, such as the polyparaphenylenevinylene derivatives and polyfluorene derivatives described in WO 90/13148 A1 or emitters from the class of low molecular weight emitters, also referred to in the art as "small molecules", such as aluminum complexes, eg Tris (8-hydroxyquinolinato) aluminum (Alq ₃ ), fluorescent dyes, for example quinacridones, or phosphorescent emitters, for example Ir (ppy) _3. Emitter materials are, for example, in DE 196 27 071 A1 described.

In addition to the layers listed above, further functional layers can be contained in such an electroluminescent layer structure (EL arrangement), such as, for example, further charge-injecting, for example electron-injecting, charge-transporting or charge-blocking intermediate layers. Such layer structures are known to the person skilled in the art and are described, for example, in JR Sheats et al., Science 273, (1996), 884. A shift can also take on several tasks. For example, the emitter materials listed above can be used in combination with a hole-transporting intermediate layer between hole-injecting and emitter layer (cf., for example, US Pat US 4,539,507 A and US 5,150,006 A ).

The basic production of such EL arrangements is known to the person skilled in the art. For example, they can be made by applying an electrode from solution or dispersion or by vapor deposition onto a substrate. For example, metal oxide or semi-transparent metal film electrodes are preferably applied by vapor deposition, whereas semi-transparent, conductive polymer electrodes are preferably applied to the substrate from solution or dispersion. If appropriate, an adhesion promoter can be applied to the substrate before application of the electrode material - by vapor deposition or from solution or dispersion. Some such electrode material coated substrates are also already commercially available (eg K-glass, ITO coated glass substrates). The hole-injecting layer can then be applied to the electrode, which is advantageously carried out from solution or dispersion in the case of the EL arrangements with hole-injecting layer containing a formulation according to the invention. The further layers are then applied to the hole-injecting layer in the order listed below, taking into account that individual layers can be omitted, depending on the material used, from solution or dispersion or by vapor deposition. Subsequently, the layer arrangement is contacted and encapsulated.

The Preparation of the hole-injecting layer containing a formulation according to the invention is done according to known technologies. For this purpose, a formulation of the invention - optionally in a solvent - on a Electrode, preferably the base electrode, applied as a film. When solvent are those listed above polar diluents, preferably water, alcohols or mixtures of these. suitable Alcohols are e.g. Methanol, ethanol, n-propanol, 2-propanol and n-butanol.

The Use of these solvents has the advantage that more layers of organic solvents, such as aromatic or aliphatic hydrocarbon mixtures applied can be without that the hole-injecting layer is attacked.

The inventive formulation - optionally in a solvent - for example, by Techniques such as spincoating, casting, doctoring, printing, curtain coating etc. evenly distributed on the electrode become. Subsequently can the layers at room temperature or temperatures up to 300 ° C, preferably 100 to 200 ° C be dried.

The formulation according to the invention - optionally in a solvent - may also preferably be applied structured by techniques such as ink-jet. This technique is known to those skilled in the art and using water-soluble and dispersed polythiophenes such as 3,4-polyethylenedioxythiophene: polystyrene sulfonic acid (PEDT: PSS), for example, in Science, Vol 279, 1135, 1998 and DE 198 41 804 A1 described.

Preferably be the formulations of the invention - optionally in a solvent - before the Application filtered through a filter.

Particularly readily filterable formulations are obtained, for example, if, based on one part by weight of polythiophene (s) containing recurring units of the general formula (I), preferably 1 to 30 parts by weight, particularly preferably 2 to 15 parts by weight of the or the SO ₃ ^- M ⁺ - or COO ^- M ⁺ groups-containing polymer (s) (e) are used, very particularly preferably the formulations of the present invention, the or polythiophene (s) comprising recurring units of the general formula (I) and the, or SO ₃ ^- M ⁺ - or COO ^- Polymer (s) containing M ⁺ groups in a weight ratio of polythiophene (s) to polymer (s) containing SO ₃ ^- M ⁺ or COO ^- M ⁺ groups of 1 to 2 to 1 to 15 contain.

The Thickness of the hole injecting layer is, for example, 3 to 500 nm, preferably 10 to 200 nm.

The influence of a hole-injecting layer containing a formulation according to the invention on the properties of the EL device can be tested in a specific structure of such an EL device according to the invention. For this purpose, the hole-injecting layer is applied to wet-chemically cleaned ITO substrate by means of spin coaters. Subsequently, the layer is dried at 100-200 ° C for 5 min. Depending on the spinning speed, the layer thickness is 20-300 nm. As the emitter layer, a 1% strength by weight solution of a polyfluorene-based emitter material (Green 1300 LUMATION ^™ from Dow Chemical Company) is spin-coated in xylene. The thickness of the emitter layer is typically 60-120 nm. Finally, a 5 nm thick Ba layer and then a 200 nm thick Ag layer are evaporated on as the cathode. By contacting the indium tin oxide (ITO) anode and the metal cathode, current-voltage-luminance characteristics are recorded and lifetimes measured by means of a characteristic plotter and a calibrated photodiode. For this purpose, a constant electric current or an alternating current is sent through the arrangement, and the voltage and the luminance are tracked time-dependent.

The organic light emitting diodes according to the invention are characterized by a long service life, high luminous intensity, low threshold voltages and a high ratio of rectification. Produced as compared to known light-emitting diodes with hole-injecting layers of a poly (ethylene 3,4-): polystyrene sulfonic acid (PEDT: PSS) dispersion (Baytron ^® P, HC Starck GmbH) was found, surprisingly, that the lifetimes of the invention organic light emitting diodes with hole-injecting layer containing a formulation according to the invention are significantly higher.

Examples

example 1

Preparation of a formulation of poly (3,4-ethylenedioxythiophene) / polystyrenesulfonic acid and a perfluorinated polymer.

40 of a 1.32% solution of poly (3,4-ethylenedioxythiophene) / polystyrenesulfonic acid solution g (HC Starck GmbH, Baytro ^® P, TP AI 4083) are reacted with 9.96 g of a 5.30 wt .-% solution of Nafion ^® in a mixture of lower aliphatic alcohols and water (Nafion ^® perfluorinated ionexchange resin, 5 wt% solution in lower Aliphatic alcohols / H ₂ O ", CAS no. 66796-30-3, Aldrich part no. 27.470-4 ., nachgemessener solids content of 5.30 wt .-%) The mixed weight ratio of PEDT / PSS / Nafion ^® is 1: 6: 7.

Example 2

The inventive formulation from Example 1 is used to build an organic light emitting diode (OLED) used. The OLED is manufactured as follows:

1. Preparation of the ITO-coated substrate

ITO-coated glass (Merck Balzers AG, FL, Part No. 253 674 XO) is cut into 50 mm x 50 mm pieces (substrates). The ITO layer is patterned by conventional photoresist technique and then etched in FeCl ₃ solution. The insulated ITO strips have a width of 2.0 mm. The substrates are then cleaned in 3% aqueous Mukasollösung in an ultrasonic bath for 15 min. Thereafter, the substrates are rinsed with distilled water and spun dry in a centrifuge. This rinsing and drying process is repeated 10 times. Immediately prior to coating, the ITO coated sides are cleaned in a UV / ozone reactor (PR-100, UVP Inc., Cambridge, UK) for 10 minutes.

2. Apply the hole-injecting layer

Approximately 10 ml of the formulation according to the invention from Example 1 are filtered (Millipore HV, 0.45 microns). The cleaned ITO-coated substrate is placed on a paint spinper and the filtered solution is distributed on the ITO-coated side of the substrate. Subsequently, will the supernumerary solution by rotation of the plate at 800 U / min with the lid closed over the Spun off over a period of 30 s. After that, the so coated Substrate for 5 min at 200 ° C dried on a hot plate. The layer thickness is 85 nm (Tencor, Alphastep 500).

3. Apply the emitter layer

5 ml of a 1% by weight xylene solution of the emitter Green 1300 LUMATION ^™ (Dow Chemical Company) are filtered (Millipore HV, 0.45 μm) and spread on the dried hole-injecting layer. This and all other process steps are carried out in pure N ₂ atmosphere (inert gas glove box system, M. Braun, Garching). The hole injection layer is previously further dried in the glove box for 5 min at 200 ° C. Subsequently, the supernatant solution of the emitter is spun off for 30 s by rotating the plate at 400 rpm with the lid closed. Thereafter, the thus coated substrate is dried for 15 minutes at 130 ° C on a hot plate. The total layer thickness is 185 nm.

4. Apply the metal cathode

On the emitter layer, a metal electrode is evaporated. The substrate is placed with the emitter layer facing down on a stripe mask with 2.0 mm wide strips oriented perpendicular to the ITO strips. From two Aufdampfschiffchen a 5 nm thick Ba layer and then a 200 nm thick Ag layer are vapor-deposited successively at a pressure of p = 10 ^-3 Pa. The vapor deposition rates are 10 Å / s for Ba and 20 Å / s for Ag. The active luminous area at the intersection of the two electrodes is 4 mm ² .

5. Encapsulation the OLEDs

The easily oxidizable cathodes are protected from corrosion by encapsulation. This is the Manually removes polymeric layers at the edge of the substrate with a scalpel and a metal cap (35 mm × 35 mm × 2 mm) is glued on with an epoxy adhesive (UHU Plus, UHU, D) as protection. Moisture absorber (GDO / CA / 18 × 10 × 0.4, SAES Getters SpA, Italy) is additionally set in the metal cap.

6. Characterization of OLED

The two electrodes of the organic LED are connected (contacted) via electrical leads to a voltage source. The positive pole is connected to the ITO electrode, the negative pole is connected to the metal electrode. The dependence of the OLED current and the electroluminescence intensity (the detection is done with a photodiode (EG & G C30809E) of the voltage are recorded, and then the lifetimes are determined by a constant current of I = 0.32 mA (8 mA / cm ² ) Arrangement flows, and tracks the voltage and light intensity time-dependent.

Comparative Example 2.1

Production of an OLED with poly (3,4-ethylenedioxythiophene) / polystyrenesulfonic acid as hole-injecting layer:

The execution takes place as in Example 2, with the following deviation in the process step 2 .:

2. Apply the hole injection layer

About 10 ml of a 1.3% poly (3,4-ethylenedioxythiophene) / polystyrenesulfonic acid solution (HC Starck GmbH, Baytron ^® P, TP AI 4083), are filtered (Millipore HV, 0.45 micron). The ITO-coated substrate is then placed on a spin coater and the filtered solution is spread on the ITO-coated side of the substrate. Subsequently, the supernatant solution is spun off by rotation of the plate at 600 rev / min with the lid closed over the period of 30 s. Thereafter, the thus coated substrate is dried for 5 minutes at 200 ° C on a hot plate. The layer thickness is 85 nm.

The Applying the metal cathodes according to process step 4 was carried out together with the layer constructions of Example 2, for comparability to ensure.

Lifetime measurements at constant current (I = 8 mA / cm ² ) of the arrangements of Example 2 and Comparative Examples 2.1

The EL device according to the invention with the hole-injecting layer containing the formulation according to the invention (Example 1) is more efficient and has significantly higher lifetime compared with the EL devices provided with a hole injecting layer made of known material (PEDT: PSS from Comparative Example 2.1) is. After 260 h long-term test, not only is the decrease in the electroluminescence intensity lower, but also the voltage increase.

Example 3.1:

Preparation of a formulation of poly (3,4-ethylenedioxythiophene) / polystyrenesulfonic acid and a perfluorinated polymer.

15 g of a desalted, 1.36% strength polyethylenedioxythiophene / polystyrenesulfonic acid solution (HC Starck GmbH, Baytron ^® P, TP AI desalted 4083) are reacted with 4.09 g Nafion ^® solution (LIQUION ^® 1000, 5 wt% solution in 2 -Propanol / H ₂ O, 1000 Aq, Ion Power Inc., US). The weight ratio of PEDT / PSS / Nafion ^® corresponds to 1: 1.

Example 3.2:

Preparation of a formulation of poly (3,4-ethylenedioxythiophene) / polystyrenesulfonic acid and a perfluorinated polymer.

12 g of a desalted, 1.36% strength polyethylenedioxythiophene / polystyrenesulfonic acid solution (HC Starck GmbH, Baytron ^® P, TP AI desalted 4083) are reacted with 3.42 g Nafion ^® solution (LIQUION ^® 1100 5 wt% solution in 2 -Propanol / H ₂ O, 1100 Aq, Ion Power Inc., US). The weight ratio of PEDT / PSS / Nafion ^® corresponds to 1: 1.

Example 4.1:

The inventive formulation from example 3.1 is used to construct an organic light-emitting diode (OLED) used. In the production of the OLED proceed as in Example 2, with the following deviation in process step 2 .:

2. Apply the hole injection layer

Approximately 10 ml of the formulation according to the invention from Example 3.1 are filtered (Millipore HV, 0.45 microns). The cleaned ITO-coated substrate is placed on a paint spinper and the filtered solution is distributed on the ITO-coated side of the substrate. Subsequently, will the supernumerary solution by rotation of the plate at 800 U / min with the lid closed over the Spun off over a period of 30 s. After that, the so coated Substrate for 5 min at 200 ° C dried on a hot plate. The layer thickness is 85 nm (Tencor, Alphastep 500).

Example 4.2:

The inventive formulation from Example 3.2 is used to construct an organic light-emitting diode (OLED) used. In the production of the OLED proceed as in Example 2, with the following deviation in process step 2 .:

2. Apply the hole injection layer

Approximately 10 ml of the formulation according to the invention from Example 3.2 are filtered (Millipore HV, 0.45 microns). The cleaned ITO-coated substrate is placed on a paint spinper and the filtered solution is distributed on the ITO-coated side of the substrate. Subsequently, will the supernumerary solution by rotation of the plate at 800 U / min with the lid closed over the Spun off over a period of 30 s. After that, the so coated Substrate for 5 min at 200 ° C dried on a hot plate. The layer thickness is 85 nm (Tencor, Alphastep 500).

Comparative Example 4.3:

Production of an OLED with poly (3,4-ethylenedioxythiophene) / polystyrenesulfonic acid as hole-injecting layer:

The execution takes place as in Example 2, with the following deviation in the process step 2 .:

2. Apply the hole injection layer

About 10 ml of a 1.36% strength desalted poly (3,4-ethylenedioxythiophene) / polystyrenesulfonic acid solution (HC Starck GmbH, Baytron ^® P, TP AI 4083), are filtered (Millipore HV, 0.45 micron). The ITO-coated substrate is then placed on a spin coater and the filtered solution is spread on the ITO-coated side of the substrate. Subsequently, the supernatant solution is spun off by rotation of the plate at 600 rev / min with the lid closed over the period of 30 s. Thereafter, the thus coated substrate is dried for 5 minutes at 200 ° C on a hot plate. The layer thickness is 85 nm.

The Applying the metal cathodes according to process step 4 was carried out together with the layer structures from Examples 4.1 and 4.2, to ensure comparability.

Lifetime measurements at constant current (I = 24 mA / cm ² ) of the arrangements of Examples 4.1, 4.2 and Comparative Example 4.3:

The EL devices according to the invention with the hole-injecting layer containing the formulations according to the invention (Examples 4.1 and 4.2) are more efficient and have significantly longer lifetimes compared with the EL array having a hole injecting Layer of known material (PEDT: PSS from Comparative Example 4.3) is constructed. After 100 h long-term test with high device current is not only the decrease in electroluminescence intensity, but also the voltage increase in the inventive EL arrangements lower.

Claims (13)

Formulation containing at least one polythiophene containing repeating units of the general formula (I),

where A is an unsubstituted or substituted C ₁ -C ₅ -alkylene radical, R is a linear or branched C ₁ -C ₁₈ -alkyl radical, a C ₅ -C ₁₂ -cycloalkyl radical, a C ₆ -C ₁₄ -aryl radical, a C ₇ -C ₁₈ aralkyl radical, a C ₁ -C ₄ hydroxyalkyl radical or a hydroxyl radical, x is an integer from 0 to 8 and in the event that several radicals R are bonded to A, these may be the same or different, at least one polymer containing SO ₃ ^- M ⁺ or COO ^- M ⁺ groups, where M ^{+ is} H ⁺ , Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , Cs ⁺ or NH ₄ ⁺ , and at least one SO ₃ ^- Partially fluorinated or perfluorinated polymer containing M ⁺ or COO ^- M ⁺ groups, where M ^{+ is} H ⁺ , Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , Cs ⁺ or NH ₄ ⁺ . A formulation according to claim 1, characterized in that M ^{+ is} independently H ⁺ , Na ⁺ or K ⁺ . Formulation according to claim 1 or 2, characterized in that A is an optionally substituted Ethylene or propylene radical. A formulation according to at least one of claims 1 to 3, characterized in that at least one polythiophene containing repeating units of the general formula (I) is one containing repeating units of the general formula (Ia),

wherein R and x have the meaning given in claim 1. Formulation according to at least one of the claims 1 to 4, characterized in that x is 0 or 1. Formulation according to at least one of claims 1 to 5, characterized in that it contains polystyrene sulfonic acid (PSS) as at least one polymer containing SO ₃ ^- M ⁺ or COO ^- M ⁺ groups. Formulation, that it contains as at least one SO ₃ according to at least one of claims 1 to 6, characterized in that ^- M ⁺ - or COO ^- M ⁺ groups containing containing partially fluorinated or perfluorinated polymer Nafion ^®. Formulation according to at least one of claims 1 to 7, characterized in that it contains polystyrenesulphonic acid (PSS) as SO3 ^- M ⁺ or COO ^- M ⁺ group ^- containing polymer and as SO ₃ ^- M ⁺ or COO ^- M ⁺ groups partially fluorinated or perfluorinated polymer Nafion ^® contains. Formulation according to at least one of Claims 1 to 8, characterized in that it comprises the polythiophene (s) containing recurring units of the general formula (I) and the SO ₃ ^- M ⁺ or COO ^- M ⁺ group (s) containing n), partially fluorinated or perfluorinated polymer (s) in a weight ratio of polythiophene (s) to SO ₃ ^- M ⁺ or COO ^- M ⁺ groups containing, partially fluorinated or perfluorinated polymer (s) from 1 to 2 to 1 to 15. Formulation according to at least one of the claims 1 to 9, characterized in that they at least one polar thinner contains. Formulation according to claim 10, characterized in that as a polar diluent Water, alcohols or mixtures containing these are used. Formulation according to claim 10 or 11, characterized in that as a polar diluent Water, methanol, ethanol, n-propanol, 2-propanol or n-butanol or mixtures containing these. Use of the formulation according to at least one of claims 1 to 12 for producing hole injecting or hole transporting Layers in EL arrangements, organic solar cells, organic Laser diodes, organic thin-film transistors or organic field effect transistors, for the production of electrodes or more electrically conductive Coatings.