MATERIALS FOR ORGANIC ELECTROLUMINESCENT DEVICES

Abstract

The invention relates to fluorene derivatives and electronic devices, particularly organic electroluminescent devices in which said compounds are used, particularly as a matrix material for phosphorescent emitters.

Claims

1. A compound of the formula (1) ##STR00358## where the symbols used are as follows: Ar is an aromatic ring system which has 6 to 30 aromatic ring atoms and may be substituted by one or more R.sup.3 radicals, or a dibenzofuran or dibenzothiophene group, each of which may be substituted by one or more R.sup.3 radicals, or a combination of an aromatic ring system having 6 to 18 aromatic ring atoms and a dibenzofuran or dibenzothiophene group, where these groups may each be substituted by one or more R.sup.3 radicals; Ar here may form a ring system together with the adjacent substituent R; R is the same or different at each instance and is H, D, a straight-chain alkyl or alkoxy group having 1 to 20 carbon atoms or a branched or cyclic alkyl or alkoxy group having 3 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms, where the alkyl, alkoxy or alkenyl group may in each case be substituted by one or more R.sup.3 radicals, where one or more hydrogen atoms may be replaced by D, or an aromatic ring system which has 6 to 30 aromatic ring atoms and may be substituted by one or more R.sup.3 radicals, or a dibenzofuran or dibenzothiophene group, each of which may be substituted by one or more R.sup.3 radicals; it is also possible here for two or more adjacent substituents R together to form a mono- or polycyclic aliphatic ring system; in addition, it is possible for R with an adjacent Ar group to form a ring system; R.sup.1, R.sup.2 is the same or different at each instance and is H, D, a straight-chain alkyl or alkoxy group having 1 to 20 carbon atoms or a branched or cyclic alkyl or alkoxy group having 3 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms, where the alkyl, alkoxy or alkenyl group may in each case be substituted by one or more R.sup.3 radicals, where one or more hydrogen atoms may be replaced by D, or an aromatic ring system which has 6 to 30 aromatic ring atoms and may be substituted by one or more R.sup.3 radicals, or a dibenzofuran or dibenzothiophene group, each of which may be substituted by one or more R.sup.3 radicals; it is possible here for multiple adjacent substituents R.sup.1 together to form a ring system; in addition, it is possible for multiple adjacent substituents R.sup.2 together to form a ring system; R.sup.3 is the same or different at each instance and is H, D, a straight-chain alkyl or alkoxy group having 1 to 20 carbon atoms or a branched or cyclic alkyl or alkoxy group having 3 to 20 carbon atoms, where the alkyl or alkoxy group may in each case be substituted by one or more R.sup.4 radicals, where one or more hydrogen atoms may be replaced by D, or an aromatic ring system which has 6 to 30 aromatic ring atoms and may be substituted by one or more R.sup.4 radicals, or a dibenzofuran or dibenzothiophene group, each of which may be substituted by one or more R.sup.4 radicals; it is also possible here for two or more adjacent substituents R.sup.3 together to form a ring system; R.sup.4 is the same or different at each instance and is H, D or an aliphatic and/or aromatic hydrocarbyl radical having 1 to 20 carbon atoms.

2. The compound according to claim 1, wherein the compound is selected from the compounds of the formulae (2a), (2b) and (2c) ##STR00359## where the symbols used have the definitions given in claim 1.

3. The compound according to claim 1, wherein the compound is selected from the compounds of the formulae (3a) and (3b) ##STR00360## where the symbols used have the definitions given in claim 1.

4. The compound according to claim 1, wherein the compound is selected from the compounds of the formulae (4a) to (4f) ##STR00361## ##STR00362## where the symbols used have the definitions given in claim 1.

5. The compound according to claim 1, wherein the compound is selected from the compounds of the formulae (6a) to (6f) ##STR00363## ##STR00364## where the symbols used have the definitions given in claim 1.

6. The compound according to claim 1, wherein Ar is selected from the group consisting of phenyl, biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, naphthalene, dibenzofuran, dibenzothiophene, phenanthrene, triphenylene or a combination of these groups, each of which may be substituted by one or more R.sup.3 radicals.

7. The compound according to claim 1, wherein the compound is selected from the compounds of the formulae (2d), (6g) and (6h) ##STR00365## where the symbols used have the definitions given in claim 1.

8. The compound according to claim 1, wherein the compound is selected from the compounds of the formulae (8a), (8b), (9a) and (9b) ##STR00366## where the symbols used have the definitions given in claim 1.

9. A composition comprising at least one compound according to claim 1 and at least one further functional material, wherein the further functional.

10. A formulation comprising at least one compound according to claim 1 and at least one organic solvent.

11. Use of a compound according to claim 1 in an electronic device.

12. An electronic device comprising at least one compound according to claim 1 or a composition according to claim 9.

13. The electronic device according to claim 12 which is an organic electroluminescent device, characterized in that the emitting layer comprises said at least one compound.

14. The electronic device according to claim 13, characterized in that the emitting layer contains at least one triazine, quinazoline or pyrimidine derivative of one of the formulae (10), (11) and (12) ##STR00367## where R.sup.3 is the same or different at each instance and is H, D, a straight-chain alkyl or alkoxy group having 1 to 20 carbon atoms or a branched or cyclic alkyl or alkoxy group having 3 to 20 carbon atoms, where the alkyl or alkoxy group may in each case be substituted by one or more R.sup.4 radicals, where one or more hydrogen atoms may be replaced by D, or an aromatic ring system which has 6 to 30 aromatic ring atoms and may be substituted by one or more R.sup.4 radicals, or a dibenzofuran or dibenzothiophene group, each of which may be substituted by one or more R.sup.4 radicals; it is also possible here for two or more adjacent substituents R.sup.3 together to form a ring system; R.sup.4 is the same or different at each instance and is H, D or an aliphatic and/or aromatic hydrocarbyl radical having 1 to 20 carbon atoms Ar.sup.2 is the same or different at each instance and is an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and may be substituted by one or more R.sup.5 radicals; R.sup.5 is the same or different at each instance and is H, D, F, Cl, Br, I, CN, NO.sub.2, N(R.sup.3).sub.2, OR.sup.3, SR.sup.3, COOR.sup.3, C(═O)N(R.sup.3).sub.2, Si(R.sup.3).sub.3, B(OR.sup.3).sub.2, C(═O)R.sup.3, P(═O)(R.sup.3).sub.2, S(═O)R.sup.3, S(═O).sub.2R.sup.3, OSO.sub.2R.sup.3, a straight-chain alkyl or alkoxy group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl or alkoxy group having 3 to 20 carbon atoms, where the alkyl, alkoxy, alkenyl or alkynyl group may in each case be substituted by one or more R.sup.3 radicals, where one or more nonadjacent CH.sub.2 groups may be replaced by Si(R.sup.3).sub.2, C═O, NR.sup.3, O, S or CONR.sup.3, or an aromatic or heteroaromatic ring system which has 5 to 30 aromatic ring atoms and may be substituted in each case by one or more R.sup.3 radicals; at the same time, two R.sup.5 radicals together may also form an aliphatic, heteroaliphatic, aromatic or heteroaromatic ring system.

15. A formulation comprising the composition according to claim 9 and at least one organic solvent.

16. An electronic device comprising the composition according to claim 9.

17. An electronic device which is an organic electroluminescent device comprising an emitting layer which comprises at least one compound according to claim 1.

18. The electronic device according to claim 17, wherein the emitting layer contains at least one triazine, quinazoline or pyrimidine derivative of one of the formulae (10), (11) and (12) ##STR00368## where R.sup.3 is the same or different at each instance and is H, D, a straight-chain alkyl or alkoxy group having 1 to 20 carbon atoms or a branched or cyclic alkyl or alkoxy group having 3 to 20 carbon atoms, where the alkyl or alkoxy group may in each case be substituted by one or more R.sup.4 radicals, where one or more hydrogen atoms may be replaced by D, or an aromatic ring system which has 6 to 30 aromatic ring atoms and may be substituted by one or more R.sup.4 radicals, or a dibenzofuran or dibenzothiophene group, each of which may be substituted by one or more R.sup.4 radicals; it is also possible here for two or more adjacent substituents R.sup.3 together to form a ring system; R.sup.4 is the same or different at each instance and is H, D or an aliphatic and/or aromatic hydrocarbyl radical having 1 to 20 carbon atoms; Ar.sup.2 is the same or different at each instance and is an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and may be substituted by one or more R.sup.5 radicals; R.sup.5 is the same or different at each instance and is H, D, F, Cl, Br, I, CN, NO.sub.2, N(R.sup.3).sub.2, OR.sup.3, SR.sup.3, COOR.sup.3, C(═O)N(R.sup.3).sub.2, Si(R.sup.3).sub.3, B(OR.sup.3).sub.2, C(═O)R.sup.3, P(═O)(R.sup.3).sub.2, S(═O)R.sup.3, S(═O).sub.2R.sup.3, OSO.sub.2R.sup.3, a straight-chain alkyl or alkoxy group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl or alkoxy group having 3 to 20 carbon atoms, where the alkyl, alkoxy, alkenyl or alkynyl group may in each case be substituted by one or more R.sup.3 radicals, where one or more nonadjacent CH.sub.2 groups may be replaced by Si(R.sup.3).sub.2, C═O, NR.sup.3, O, S or CONR.sup.3, or an aromatic or heteroaromatic ring system which has 5 to 30 aromatic ring atoms and may be substituted in each case by one or more R.sup.3 radicals; at the same time, two R.sup.5 radicals together may also form an aliphatic, heteroaliphatic, aromatic or heteroaromatic ring system.

19. A composition comprising at least one compound according to claim 1 and at least one further functional material, wherein the further functional material is selected from a phosphorescent emitter, an emitter that exhibits TADF, and/or a matrix material selected from the group consisting of electron transport materials, hole transport materials and bipolar materials.

Description

EXAMPLES

[0092] The syntheses which follow, unless stated otherwise, are conducted under a protective gas atmosphere in dried solvents. The solvents and reagents can be purchased from ALDRICH or ABCR. The numbers given for the reactants that are not commercially available are the corresponding CAS numbers.

[0093] The following synthesis units can be used for synthesis of the materials of the invention:

[0094] Boronic Acids

##STR00243## ##STR00244##

[0095] Ortho-Bromomethyl Ester

##STR00245##

[0096] Syntheses of the Materials of the Invention

Example 1: Coupling of ortho-bromobenzoate and [1,1′-biphenyl]-2-boronic Acid

[0097] ##STR00246##

[0098] In a baked-out 1 l 4-neck flask with precision glass stirrer, reflux condenser, thermometer and protective gas connection, 30 g (139.5 mmol) of 2-bromobenzoate (BB-9), 33.2 g (167.4 mmol, 1.2 eq.) of biphenyl-2-boronic acid (BB-1), 32.5 g (306.9 mmol, 2.2 eq.) of sodium carbonate and 1.83 g (6.98 mmol, 0.05 eq.) of triphenylphosphine are dissolved in 450 ml of THE and 150 ml of water and degassed. 0.78 g (3.49 mmol, 0.025 eq.) of palladium(II) acetate is added to the reaction mixture, which is stirred under reflux for 24 h. After cooling to room temperature, 300 ml of ethyl acetate are added, the organic phase is separated off and the solvent is removed under reduced pressure. The residue is taken up in ethyl acetate, filtered through silica gel and dried under reduced pressure. 33.5 g (116.2 mmol, 83% yield) of the colourless solid BB-50 is obtained.

[0099] Analogously to this method, the boronic acids specified can be coupled to methyl ortho-bromobenzoates with similar yields:

##STR00247## ##STR00248## ##STR00249## ##STR00250## ##STR00251##

Example 2: Conversion of the Methyl Esters to 9,9′-diarylfluorenes

Synthesis Units:

[0100] ##STR00252##

##STR00253##

[0101] In a baked-out 1 l 4-neck flask with precision glass stirrer, reflux condenser, thermometer and protective gas connection, 27.65 ml (228.9 mmol) of 1,3-dibromobenzene BB-90 (CAS: 108-36-1) is dissolved in 450 ml of anhydrous 2-methoxy-2-methylpropane, inertized with argon and cooled down to −70° C. 143.7 ml (228.9 mmol, 1 eq.) of a 15% n-butyllithium solution in n-hexane is gradually added dropwise at such a rate that the internal temperature does not exceed −65° C. The solution is stirred at −70° C. for a further 90 minutes. This gives rise to a white suspension. 30 g (132.9 mmol) of methyl [1,1′,2′,1″ ]terphenyl-2-carboxylate (BB-50) is dissolved in 18.3 ml of anhydrous 2-methoxy-2-methylpropane, inertized with argon and gradually added dropwise to the white suspension at such a rate that the internal temperature does not rise above −65° C. The mixture is thawed gradually to room temperature overnight. 200 ml of water is rapidly metered in and the mixture is stirred for 60 minutes. The aqueous phase is separated off and the organic phase is freed of sufficient solvent for it to turn cloudy. 300 ml of heptane is added, such that a solid precipitates out of the solution. The solid is filtered off with suction, washed with heptane and dried.

[0102] The dried solid is transferred to a 4 l 4-neck flask with reflux condenser, precision glass stirrer, thermometer and protective gas connection, and admixed with 950 ml of 100% acetic acid and 22 ml of 25% hydrochloric acid. The mixture is heated under reflux for 72 h, giving rise to a brown solution. After cooling to room temperature, 1000 ml of water are added, such that the solution turns cloudy. The product is extracted with toluene. 30.5 g (55.24 mmol, 53% yield) of the colourless solid BB-100 is obtained.

[0103] It is possible to prepare the following intermediates with similar yields and identical reaction conditions:

##STR00254## ##STR00255## ##STR00256## ##STR00257## ##STR00258## ##STR00259## ##STR00260## ##STR00261## ##STR00262## ##STR00263## ##STR00264## ##STR00265##

Example 3: Synthesis of the Materials of the Invention

[0104] The following are among the synthesis units that can be utilized for synthesis of the materials of the invention:

##STR00266##

##STR00267##

[0105] The following are weighed into a 2 l multineck flask with reflux condenser, argon connection and precision glass stirrer: 15 g (27.16 mmol) of BB-100, 24.07 g (55.68 mmol, 2.05 eq.) BB-180, 3.14 g (2.72 mmol, 0.1 eq.) of tetrakis(triphenylphosphine)palladium(0) (CAS: 14221-01-3), followed by inertization. 400 ml of tetrahydrofuran and 85 ml of a 20% tetraethylammonium hydroxide solution in water are added, followed by inertization again. The reaction mixture is heated under reflux for 24 h, cooled down and admixed with water. The phases are separated, and the organic phase is extracted with water and dried over sodium sulfate. The solvent is removed under reduced pressure, and the residue is taken up in toluene and filtered through silica gel. The solvent is removed under reduced pressure and the residue is dried in a drying cabinet. The solid is repeatedly recrystallized from ethyl acetate. 3.1 g of a colourless solid M-0002 (11% yield, 3.09 mmol) are obtained.

[0106] Further materials of the invention can be obtained in similar yields by identical reaction conditions:

##STR00268## ##STR00269## ##STR00270## ##STR00271## ##STR00272## ##STR00273## ##STR00274## ##STR00275## ##STR00276## ##STR00277## ##STR00278## ##STR00279## ##STR00280## ##STR00281## ##STR00282## ##STR00283## ##STR00284## ##STR00285## ##STR00286## ##STR00287## ##STR00288## ##STR00289## ##STR00290## ##STR00291## ##STR00292## ##STR00293## ##STR00294## ##STR00295## ##STR00296## ##STR00297## ##STR00298## ##STR00299## ##STR00300## ##STR00301## ##STR00302## ##STR00303## ##STR00304##

##STR00305## ##STR00306## ##STR00307## ##STR00308## ##STR00309## ##STR00310## ##STR00311## ##STR00312## ##STR00313## ##STR00314## ##STR00315## ##STR00316## ##STR00317## ##STR00318## ##STR00319## ##STR00320## ##STR00321## ##STR00322## ##STR00323## ##STR00324## ##STR00325## ##STR00326## ##STR00327## ##STR00328## ##STR00329## ##STR00330## ##STR00331## ##STR00332## ##STR00333## ##STR00334## ##STR00335## ##STR00336## ##STR00337## ##STR00338## ##STR00339## ##STR00340## ##STR00341## ##STR00342## ##STR00343## ##STR00344## ##STR00345##

Device Examples

Example 1: Processibility

[0107] One way of processing the materials of the invention is from solution. They are notable here for elevated solubility compared to symmetric comparative compounds, as shown in Table 1. In addition, it is a feature of materials of the invention that their shade stability is elevated, as apparent from the long-term solubility data in Table 1.

[0108] The inventive compound M-0005 is directly comparable to compound B-1 and differs merely by the presence or absence of the Ar group on the fluorene. It can be seen that the solubility of M-0005 in cyclohexylbenzene is significantly better than the solubility of B-1. In addition, the long-term stability of the solution of M-0005 in mesitylene is significantly better than that of B-1 in mesitylene.

[0109] The inventive compounds M-0002, M-0097 and M-0226 are directly comparable to compound B-2 and differ merely or essentially by the presence or absence of the Ar group on the fluorene. It can be seen that the solubility of the inventive compounds M-0097 and M-0226 in toluene and mesitylene is significantly better than the solubility of B-2. In addition, the long-term stability of the solutions of M-0097 and M-0226 is significantly better than that of B-2.

TABLE-US-00003 TABLE 1 Solubility Solubility after 24 hours [g/l] Solubility after 7 days [g/l] Cyclohex- Mesi- Cyclohex- Mesi- Ex. Material ylbenzene Tetralin Toluene tylene ylbenzene Tetralin Toluene tylene C1.1 B-1 <20 >50 >50 >50 <20 >50 >50 <40 C1.2 B-2 >50 >50 <1 <1 <1 <20 <1 <1 C1.3 B-3 >50 <50 >50 <50 >50 <50 >50 <40 I1.1 M-0005 >50 >50 >50 >50 >50 <50 >50 >50 I1.2 M-0002 <1 >50 >50 >50 <1 >50 >50 50 I1.3 M-0008 <50 <30 >50 >50 <50 <30 >50 >50 I1.4 M-0026 >50 >50 >50 >50 >50 >50 >50 >50 I1.5 M-0033 >50 >50 >50 >50 >50 >50 >50 >50 I1.6 M-0043 <50 >50 <50 <50 <50 >50 <50 <50 I1.7 M-0086 >50 >50 >50 >50 >50 >50 >50 >50 I1.8 M-0097 >50 >50 <20 <20 <25 <25 <20 <20 I1.9 M-0162 <50 >50 >50 >50 <50 >50 >50 >50 I1.10 M-0172 <40 <40 <30 <30 <40 <40 <30 <30 I1.11 M-0203 <40 <40 <20 <20 <40 <40 <20 <20 I1.12 M-0226 <30 <30 <20 <20 <25 <25 <20 <20 I1.13 M-0244 <50 <50 <20 <20 <40 <40 <20 <20 I1.14 M-0281 <50 <50 <50 <50 <50 <50 <50 <50 I1.15 M-0315 <50 >50 <50 <50 <50 >50 <50 <50

[0110] Method of Determining Solubility Via HPTLC

[0111] Sample preparation: The material is weighed out in two 25 mg portions (W1, W2), 0.5 ml of solvent is added, and the mixture is shaken at 60° C. for 60 minutes and then at 25° C. and 600 rpm for 24 h. When the solution is clear, more solid material is added until a saturated solution is formed. After being cooled to room temperature, the samples are filtered through a syringe filter (0.2 μm). The solutions are stored in glass vials at room temperature for 7 days, and the solubility is determined by HPTLC on days 1 and 7. For this purpose, the filtered solutions are diluted.

[0112] Calibration: Making up a standard solution: about 6 mg of substance are dissolved in 20 ml of 2-methyl-THF. If it is not possible to dissolve the material under these conditions, the concentration can be reduced. The stock solution is diluted for the calibration (standardization).

[0113] Chromatographic conditions (HPTLC): plate: HPTLC RP 18 F254, 10×20 cm eluent: methanol/2-methyl-THF 70/30 (V/V)

[0114] Migration distance: 5 cm

[0115] Recognition: 366 nm

[0116] Use volume: standard: 1, 3, 6, 10, 15, 20, 25, 30 μl

[0117] HPTLC measurement: The HPTLC plate is scanned by a TLC scanner, peaks are integrated and a calibration function is determined.

[0118] Furthermore, materials of the invention are notable in that, as shown in Table 2, films containing these materials can be baked at higher temperatures without turning cloudy and, when used in OLED components, leading to lower efficiency. The production of the corresponding OLED components is described below. The EML mixtures and structures of the OLED components examined are shown in tables 5 and 6.

[0119] For example, compound M-0002 is directly comparable to compound B-2 and differs merely by the absence of the Ar group on the fluorene. It can be seen that the layer comprising M-0002 can be baked at higher temperature without cloudiness and with a significantly smaller loss of efficiency.

TABLE-US-00004 TABLE 2 Baking at elevated temperature Loss of State of film efficiency after Ref. Elevated after baking at baking at elevated Ex. Material temp. temp. elevated temp. temperature C2.1 B-2 160 180 slightly cloudy ≥10%  C2.2 B-1 160 180 cloudy ≥70%  I2.1 M-0002 160 180 clear ≤5% C2.3 B-1 160 170 slightly cloudy ≥10%  I2.2 M-0005 160 170 clear ≤5% C2.4 B-4 150 180 slightly cloudy ≥10%  C2.5 B-1 150 180 cloudy ≥70%  I2.3 M-0002 150 180 clear ≤5% I2.4 M-0005 150 170 clear ≤5% I2.5 M-0172 150 170 clear ≤5% I2.6 M-0008 150 180 clear ≤5% I2.7 M-0026 150 180 clear ≤5% I2.8 M-0033 150 180 clear ≤5% I2.9 M-0043 150 180 clear ≤5% I2.10 M-0086 150 180 clear ≤5% I2.11 M-0097 150 180 clear ≤5% I2.12 M-0162 150 180 clear ≤5% I2.13 M-0203 150 180 clear ≤5% I2.14 M-0226 150 180 clear ≤5% I2.15 M-0315 150 180 clear ≤5%

Example 2: OLED Components

[0120] One way of processing the matrix materials of the invention is from solution. There are already many descriptions of the production of completely solution-based OLEDs in the literature, for example in WO 2004/037887 by means of spin coating. There have likewise been many previous descriptions of the production of vacuum-based OLEDs, including in WO 2004/058911. In the examples discussed hereinafter, layers applied in a solution-based and vacuum-based manner are combined within an OLED, and so the processing up to and including the emission layer is effected from solution and in the subsequent layers (hole blocker layer and electron transport layer) from vacuum. For this purpose, the previously described general methods are matched to the circumstances described here (layer thickness variation, materials) and combined as follows. The general structure is as follows: substrate/ITO (50 nm)/hole injection layer (HIL)/hole transport layer (HTL)/emission layer (EML)/optional hole blocker layer (HBL)/electron transport layer (ETL)/optional electron injection layer/cathode (aluminium, 100 nm). Substrates used are glass plates coated with structured ITO (indium tin oxide) of thickness 50 nm. For better processing, they are coated with PEDOT:PSS (poly(3,4-ethylenedioxy-2,5-thiophene) polystyrenesulfonate, purchased from Heraeus Precious Metals GmbH & Co. KG, Germany). PEDOT:PSS is spun on from water under air and subsequently baked under air at 180° C. for 10 minutes in order to remove residual water. The hole transport layer and the emission layer are applied to these coated glass plates. The hole transport layer used is crosslinkable. A polymer of the structures depicted below is used, which can be synthesized according to WO 2010/097155 or WO 2013/156130:

##STR00346##

[0121] The hole transport polymer is dissolved in toluene. The typical solids content of such solutions is about 5 g/I when, as here, the layer thickness of 20-60 nm which is typical of a device is to be achieved by means of spin-coating. The layers are spun on in an inert gas atmosphere, argon in the present case, and baked at 180° C. for 60 minutes.

[0122] The emission layer is composed of at least one matrix material (host material) and an emitting dopant (emitter). In addition, it is possible to use mixtures of a plurality of matrix materials and co-dopants. Details given in such a form as TMM-A (92%):dopant (8%) mean here that the material TMM-A is present in the emission layer in a proportion by weight of 92% and dopant in a proportion by weight of 8%. The mixture for the emission layer is dissolved in toluene or optionally chlorobenzene. The typical solids content of such solutions is about 17 g/I when, as here, the layer thickness of 60 nm which is typical of a device is to be achieved by means of spin-coating. The layers are spun on in an inert gas atmosphere, argon in the present case, and baked for 10 minutes. The materials used in the present case are shown in Table 3.

TABLE-US-00005 TABLE 3 EML materials used [00347] A-1 [00348] B-1 [00349] B-2 [00350] B-3 [00351] B-4 [00352] C-1 [00353] C-2 [00354] D-1 [00355] D-2

[0123] The materials for the hole blocker layer, electron transport layer and electron injection layer are applied by thermal vapour deposition in a vacuum chamber. The electron transport layer, for example, may consist of more than one material, the materials being added to one another by co-evaporation in a particular proportion by volume. Details given in such a form as ETM1:ETM2 (50%:50%) mean here that the ETM1 and ETM2 materials are present in the layer in a proportion by volume of 50% each. The materials used in the present case are shown in Table 4.

TABLE-US-00006 TABLE 4 HBL and ETL materials used [00356] ETM1 [00357] ETM2

[0124] The cathode is formed by the thermal evaporation of an aluminium layer of thickness 100 nm. The OLEDs are characterized in a standard manner. For this purpose, the electroluminescence spectra, current-voltage-luminance characteristics (IUL characteristics) assuming Lambertian radiation characteristics and the (operating) lifetime are determined. The IUL characteristics are used to determine indices such as, for example, external quantum efficiency at a particular brightness. LT97 @ 60 mA/cm.sup.2 is the lifetime before the OLED, given a constant current density of 60 mA/cm.sup.2, has fallen to 97% of the starting luminance.

[0125] The EML mixtures and structures of the OLED components examined are shown in Tables 5 and 6. The corresponding results can be found in Table 7.

TABLE-US-00007 TABLE 5 EML mixtures of the PLED components examined Matrix A Co-matrix B Co-dopant C Dopant D Ex. Material % Material % Material % Material % C2.1 A-1 20 B-2 60 C-1 20 — — C2.2 A-1 20 B-1 60 C-1 20 — — I2.1 A-1 20 M-0002 60 C-1 20 — — C2.3 A-1 25 B-1 53 C-2 22 — — I2.2 A-1 25 M-0005 53 C-2 22 — — C2.4 A-1 30 B-4 34 C-1 30 D-1 6 C2.5 A-1 30 B-1 34 C-1 30 D-1 6 I2.3 A-1 30 M-0002 34 C-1 30 D-1 6 I2.4 A-1 30 M-0005 34 C-1 30 D-2 6 I2.5 A-1 30 M-0172 34 C-1 30 D-1 6 I2.6 A-1 30 M-0008 34 C-1 30 D-1 6 I2.7 A-1 30 M-0026 34 C-1 30 D-1 6 I2.8 A-1 30 M-0033 34 C-1 30 D-2 6 I2.9 A-1 30 M-0043 34 C-1 30 D-2 6 I2.10 A-1 30 M-0086 34 C-1 30 D-2 6 I2.11 A-1 30 M-0097 34 C-1 30 D-1 6 I2.12 A-1 30 M-0162 34 C-1 30 D-1 6 I2.13 A-1 30 M-0203 34 C-1 30 D-1 6 I2.14 A-1 30 M-0226 34 C-1 30 D-1 6 I2.15 A-1 30 M-0315 34 C-1 30 D-1 6 C3.1 A-1 40 B-3 37 C-2 15 D-2 8 I3.1 A-1 40 M-0005 37 C-2 15 D-2 8 C3.2 A-1 40 B-3 37 C-2 15 D-2 8 I3.2 A-1 40 M-0005 37 C-2 15 D-2 8 C3.3 A-1 30 B-1 34 C-1 30 D-1 6 C3.4 A-1 30 B-2 34 C-1 30 D-1 6 I3.3 A-1 30 M-0002 34 C-1 30 D-1 6 C3.5 A-1 20 B-4 60 C-1 20 — — I3.4 A-1 20 M-0002 60 C-1 20 — — C3.6 A-1 20 B-4 60 C-1 20 — — I3.5 A-1 20 M-0002 60 C-1 20 — —

TABLE-US-00008 TABLE 6 Structure of the OLED components examined EML HIL HTL EML baking HBL ETL EIL Ex. (thickness) (thickness) thickness temperature (thickness) (thickness) (thickness) C2.1 PEDOT HTL-1 60 nm see ETM-1 ETM-1:ETM-2 — (20 nm) (20 nm) Tab. 2 (10 nm) (50:50) (40 nm) C2.2 PEDOT HTL-1 60 nm see ETM-1 ETM-1:ETM-2 — (20 nm) (20 nm) Tab. 2 (10 nm) (50:50) (40 nm) I2.1 PEDOT HTL-2 60 nm see ETM-1 ETM-1:ETM-2 (20 nm) (20 nm) Tab. 2 (10 nm) (50:50) (40 nm) C2.3 PEDOT HTL-2 60 nm see ETM-1 ETM-1:ETM-2 — (20 nm) (20 nm) Tab. 2 (10 nm) (50:50) (40 nm) I2.2 PEDOT HTL-2 60 nm see ETM-1 ETM-1:ETM-2 — (20 nm) (20 nm) Tab. 2 (10 nm) (50:50) (40 nm) C2.4 PEDOT HTL-2 60 nm see ETM-1 ETM-1:ETM-2 — (60 nm) (20 nm) Tab. 2 (10 nm) (50:50) (40 nm) C2.5 PEDOT HTL-2 60 nm see ETM-1 ETM-1:ETM-2 — (60 nm) (20 nm) Tab. 2 (10 nm) (50:50) (40 nm) I2.3 PEDOT HTL-2 60 nm see ETM-1 ETM-1:ETM-2 — (60 nm) (20 nm) Tab. 2 (10 nm) (50:50) (40 nm) I2.4 PEDOT HTL-2 60 nm see ETM-1 ETM-1:ETM-2 — (60 nm) (20 nm) Tab. 2 (10 nm) (50:50) (40 nm) I2.5 PEDOT HTL-2 60 nm see ETM-1 ETM-1:ETM-2 — (60 nm) (20 nm) Tab. 2 (10 nm) (50:50) (40 nm) I2.6 PEDOT HTL-2 60 nm see ETM-1 ETM-1:ETM-2 — (60 nm) (20 nm) Tab. 2 (10 nm) (50:50) (40 nm) I2.7 PEDOT HTL-2 60 nm see ETM-1 ETM-1:ETM-2 — (60 nm) (20 nm) Tab. 2 (10 nm) (50:50) (40 nm) I2.8 PEDOT HTL-2 60 nm see ETM-1 ETM-1:ETM-2 — (60 nm) (20 nm) Tab. 2 (10 nm) (50:50) (40 nm) I2.9 PEDOT HTL-2 60 nm see ETM-1 ETM-1:ETM-2 — (60 nm) (20 nm) Tab. 2 (10 nm) (50:50) (40 nm) I2.10 PEDOT HTL-2 60 nm see ETM-1 ETM-1:ETM-2 — (60 nm) (20 nm) Tab. 2 (10 nm) (50:50) (40 nm) I2.11 PEDOT HTL-2 60 nm see ETM-1 ETM-1:ETM-2 — (60 nm) (20 nm) Tab. 2 (10 nm) (50:50) (40 nm) I2.12 PEDOT HTL-2 60 nm see ETM-1 ETM-1:ETM-2 — (60 nm) (20 nm) Tab. 2 (10 nm) (50:50) (40 nm) I2.13 PEDOT HTL-2 60 nm see ETM-1 ETM-1:ETM-2 — (60 nm) (20 nm) Tab. 2 (10 nm) (50:50) (40 nm) I2.14 PEDOT HTL-2 60 nm see ETM-1 ETM-1:ETM-2 — (60 nm) (20 nm) Tab. 2 (10 nm) (50:50) (40 nm) I2.15 PEDOT HTL-2 60 nm see ETM-1 ETM-1:ETM-2 — (60 nm) (20 nm) Tab. 2 (10 nm) (50:50) (40 nm) C3.1 PEDOT HTL-2 90 nm 150 — ETM-1 (20 nm) ETM-2 (80 nm) (20 nm) (3 nm) I3.1 PEDOT HTL-2 90 nm 150 — ETM-1 (20 nm) ETM-2 (80 nm) (20 nm) (3 nm) C3.2 PEDOT HTL-2 90 nm 160 — ETM-1 (20 nm) ETM-2 (80 nm) (20 nm) (3 nm) I3.2 PEDOT HTL-2 90 nm 160 — ETM-1 (20 nm) ETM-2 (80 nm) (20 nm) (3 nm) C3.3 PEDOT HTL-2 60 nm 150 ETM-1 ETM-1:ETM-2 — (60 nm) (20 nm) (10 nm) (50:50) (40 nm) C3.4 PEDOT HTL-2 60 nm 150 ETM-1 ETM-1:ETM-2 — (60 nm) (20 nm) (10 nm) (50:50) (40 nm) I3.3 PEDOT HTL-2 60 nm 170 ETM-1 ETM-1:ETM-2 — (60 nm) (20 nm) (10 nm) (50:50) (40 nm) C3.5 PEDOT HTL-2 60 nm 160 ETM-1 ETM-1:ETM-2 — (20 nm) (20 nm) (10 nm) (50:50) (40 nm) I3.4 PEDOT HTL-2 60 nm 160 ETM-1 ETM-1:ETM-2 — (20 nm) (20 nm) (10 nm) (50:50) (40 nm) C3.6 PEDOT HTL-2 60 nm 150 ETM-1 ETM-1:ETM-2 — (20 nm) (20 nm) (10 nm) (50:50) (40 nm) I3.5 PEDOT HTL-2 60 nm 150 ETM-1 ETM-1:ETM-2 — (20 nm) (20 nm) (10 nm) (50:50) (40 nm)

TABLE-US-00009 TABLE 7 Results for solution-processed OLEDs EQE [%] Ex. @1000 cd/m.sup.2 LT97 @x mA/cm.sup.2 C3.1 18.4 27 60 I3.1 18.6 36 60 C3.2 18.9 31 60 I3.2 19.0 46 60 C3.3 16.5 81 60 C3.4 16.4 86 60 I3.3 16.4 131 60 C3.5 19.4 7 40 I3.4 20.3 16 40 C3.6 21.0 8 40 I3.5 21.0 12 40

[0126] As apparent from the OLED component data shown above, the materials of the invention lead to good performance data in relation to lifetime and efficiency. They offer an improvement here compared to existing comparative materials. In addition, it is found that the larger process window in relation to baking temperatures not only has practical advantages in the industrial manufacture of components but also facilitates the attainment of high component lifetimes.

[0127] For example, compound M-0005 is directly comparable with compound B-3 and differs merely by the position of the Ar group on the fluorene. It can be seen that the substitution pattern of the invention has a positive effect on the component lifetime.

[0128] Compound M-0002 is likewise directly comparable with compounds B-2 and B-4, from which it differs by the presence of the Ar group on the fluorene. It is otherwise identical to B-2; it otherwise differs from compound B-4 merely by the linkage of the phenyl rings in the 9 position of the fluorene. In both cases, M-0002 leads to improved component lifetimes, and in Example I3.4 by comparison with C3.5 additionally to an improvement in efficiency.

[0129] By comparison with comparative compound B-1 known from the prior art as well, M-0002 leads to an improvement in component lifetime.