Compositions comprising at least one polymer and at least one salt, and electroluminescent devices containing said compositions

Abstract

The present invention relates to compositions comprising at least one polymer containing repeat triarylamine units and comprising at least one salt, to processes for production thereof and to the use thereof in electronic devices, especially in organic electroluminescent devices, called OLEDs (OLED=organic light-emitting diodes). The present invention also further relates to organic electroluminescent devices comprising these compositions.

Claims

1. A composition comprising at least one conjugated polymer and at least one salt, wherein the polymer comprises at least one structural unit of formula (I) and at least one structural unit of the formula (I): ##STR00389## ##STR00390## wherein Ar.sup.1, Ar.sup.2, and Ar.sup.3 are the same or different in each instance and are a mono- or polycyclic, aromatic or heteroaromatic ring system optionally substituted by one or more R radicals, wherein the Ar.sup.3 radical of formula (I) is substituted by Ar.sup.4 in at least one ortho position, based on the position of the nitrogen atom shown in formula (I); Ar.sup.11, Ar.sup.21, and Ar.sup.31 are the same or different at each instance and are a mono- or polycyclic, aromatic or heteroaromatic ring system which may be substituted by one or more R radicals; Ar.sup.4 is a mono- or polycyclic, aromatic or heteroaromatic ring system which has 5 to 60 aromatic ring atoms and is optionally substituted by one or more R radicals; R is the same or different in each instance and is H, D, F, Cl, Br, I, N(R.sup.1).sub.2, CN, NO.sub.2, Si(R.sup.1).sub.3, B(OR.sup.1).sub.2, C(O)R.sup.1, P(O)(R.sup.1).sub.2, S(O)R.sup.1, S(O).sub.2R.sup.1, OSO.sub.2R.sup.1, a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 40 carbon atoms or an alkenyl or alkynyl group having 2 to 40 carbon atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 40 carbon atoms, each of which is optionally substituted by one or more R.sup.1 radicals, wherein one or more nonadjacent CH.sub.2 groups is optionally replaced by R.sup.1CCR.sup.1, CC, Si(R.sup.1).sub.2, CO, CS, CNR.sup.1, P(O)(R.sup.1), SO, SO.sub.2, NR.sup.1, O, S, or CONR.sup.1 and wherein one or more hydrogen atoms is optionally replaced by D, F, Cl, Br, I, or CN, an aromatic or heteroaromatic ring system which has 5 to 60 aromatic ring atoms and is optionally substituted in each case by one or more R.sup.1 radicals, an aryloxy or heteroaryloxy group which has 5 to 60 aromatic ring atoms and is optionally substituted by one or more R.sup.1 radicals, an aralkyl or heteroaralkyl group which has 5 to 60 aromatic ring atoms and is optionally substituted by one or more R.sup.1 radicals, or a diarylamino group, diheteroarylamino group, or arylheteroarylamino group which has 10 to 40 aromatic ring atoms and is optionally substituted by one or more R.sup.1 radicals; and wherein two or more R radicals together optionally define a mono- or polycyclic, aliphatic, aromatic and/or benzofused ring system; R.sup.1 is the same or different in each instance and is H, D, F, or an aliphatic, aromatic and/or heteroaromatic hydrocarbyl radical having 1 to 20 carbon atoms, wherein one or more hydrogen atoms is optionally replaced by F; and wherein two or more R.sup.1 substituents together optionally define a mono- or polycyclic, aliphatic, or aromatic ring system; and at least one structural units of formula (I) comprises at least one crosslinkable Q group; the dotted lines denote bonds to adjacent structural units in the polymer; the salt comprises at least one cation of formula (K1): ##STR00391## wherein the A.sup.1 radical is an element selected from the group consisting of Cl, Br and I; the R.sup.11 radical is any radical; the R.sup.12 radical is a carbon atom-containing group which binds via a carbon atom to the A.sup.1 radical; wherein the R.sup.11 and R.sup.12 radicals together optionally define a mono- or polycyclic, aliphatic, heteroaliphatic, heteroaromatic or aromatic ring system; and at least one anion of formula (A1): ##STR00392## wherein the E.sup.4 radical is an element of group 13 of the Periodic Table of the Elements; and the R.sup.41, R.sup.42, R.sup.43, and R.sup.44 radicals are each an aromatic or heteroaromatic ring system which has 5 to 60 aromatic ring atoms and is optionally substituted in each case by one or more R radicals, wherein one or more of the R.sup.41, R.sup.42, R.sup.43, and R.sup.44 radicals together optionally define a mono- or polycyclic, aliphatic, heteroaliphatic, heteroaromatic or aromatic ring system.

2. The composition of claim 1, wherein the polymer comprises at least one structural unit of formula (I) selected from the structural unit of formula (Ia): ##STR00393## wherein q is 0, 1, 2, 3, 4, 5, or 6; X is CR.sub.2, NR, SiR.sub.2, O, S, CO, or PO; and r is 0 or 1.

3. The composition of claim 1, wherein Ar.sup.3 is substituted by Ar.sup.4 in one of the two ortho positions, and Ar.sup.3 is additionally joined to Ar.sup.4 in the meta position adjacent to the substituted ortho position.

4. The composition of claim 1, wherein the polymer comprises at least one structural unit of formula (I) selected from the structural unit of formula (Ib): ##STR00394## wherein X is CR.sub.2, NR, SiR.sub.2, O, S, CO, or PO; m is 0, 1, 2, 3 or 4; n is 0, 1, 2, or 3; and s and t are each 0 or 1, wherein the sum of (s+t)=1 or 2.

5. The composition of claim 1, wherein the at least one structural unit of formula (I) is selected from structural units of formulae (II), (III), and (IV): ##STR00395## wherein X is CR.sub.2, NR, SiR.sub.2, O, S, CO, or PO; m is 0, 1, 2, 3 or 4; n is 0, 1, 2, or 3.

6. The composition of claim 5, wherein the at least one structural unit of formula (II) is selected from the structural unit of formula (V): ##STR00396## wherein p is 0, 1, 2, 3, 4, or 5.

7. The composition of claim 5, wherein the at least one structural unit of formula (III) is selected from the structural unit of formula (VI): ##STR00397##

8. The composition of claim 5, wherein the at least one structural unit of formula (IV) is selected from the structural unit of formula (VII): ##STR00398##

9. The composition of claim 1, wherein the polymer comprises at least one structural unit of formula (I) selected from the structural unit of formula (VIIIa): ##STR00399## or the structural unit of formula (VIIIb): ##STR00400## wherein w is 1, 2, or 3; Ar.sup.5 to Ar.sup.9 are each the same or different at each instance and are a mono- or polycyclic, aromatic or heteroaromatic ring system optionally substituted by one or more R radicals; and the dotted lines denote bonds to adjacent structural units in the polymer.

10. The composition of claim 9, wherein at least one of the Ar.sup.5 and/or Ar.sup.8 radicals of formulae (VIIIa) and/or (VIIIb) is substituted by Ar.sup.4 in at least one ortho position, based on the position of the nitrogen atom shown in formula (VIIIa) and/or (VIIIb), wherein Ar.sup.4 is a mono- or polycyclic, aromatic or heteroaromatic ring system which has 5 to 60 aromatic ring atoms and is optionally substituted by one or more R radicals.

11. The composition of claim 9, wherein the at least one structural unit of formula (VIIIa) is selected from the structural units of (VIIIa-1a), (VIIIa-1b), (VIIIa-1c), and (VIIIa-1d): ##STR00401## wherein Ar.sup.4 is a mono- or polycyclic, aromatic or heteroaromatic ring system which has 5 to 60 aromatic ring atoms and is optionally substituted by one or more R radicals; X is CR.sub.2, NR, SiR.sub.2, O, S, CO, or PO; m is 0, 1, 2, 3 or 4; n is 0, 1, 2, or 3; r is 0 or 1; and s and t are each 0 or 1, wherein the sum of (s+t)=1 or 2.

12. The composition of claim 9, wherein the at least one structural unit of the formula (VIIIa) is selected from structural units of the following formulae (IX), (X), (XI), (XII), (XIII), (XIV), (XV) and (XVI): ##STR00402## wherein Ar.sup.4 is a mono- or polycyclic, aromatic or heteroaromatic ring system which has 5 to 60 aromatic ring atoms and is optionally substituted by one or more R radicals; X is CR.sub.2, NR, SiR.sub.2, O, S, CO, or PO; m is 0, 1, 2, 3 or 4; n is 0, 1, 2, or 3; and p is 0, 1, 2, 3, 4, or 5.

13. The composition of claim 1, wherein at least one of the structural units of formulae (I) comprises at least one crosslinkable Q group.

14. The composition of claim 1, wherein the mono- or polycyclic, aromatic or heteroaromatic Ar.sup.a groups are selected from: ##STR00403## ##STR00404## wherein X is CR.sub.2, NR, SiR.sub.2, O, S, CO, or PO; the dotted lines denote bonds to adjacent structural units in the polymer; m is 0, 1, 2, 3, or 4; n is 0, 1, 2, or 3; o is 0, 1, or 2; and p is 0, 1, 2, 3, 4, or 5.

15. The composition of claim 1, wherein the mono- or polycyclic, aromatic or heteroaromatic Ar.sup.1 and Ar.sup.2 groups are selected from: ##STR00405## ##STR00406## ##STR00407## wherein X is CR.sub.2, NR, SiR.sub.2, O, S, CO, or PO; Y is CR.sub.2, SiR.sub.2, O, S, or a straight-chain or branched alkyl group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms, each of which is optionally substituted by one or more R.sup.1 radicals, and wherein one or more nonadjacent CH.sub.2 groups, CH groups, or carbon atoms in the alkyl, alkenyl, or alkynyl groups is optionally replaced by Si(R.sup.1).sub.2, CO, CS, CNR.sup.1, P(O)(R.sup.1), SO, SO.sub.2, NR.sup.1, O, S, CONR.sup.1, an aromatic or heteroaromatic ring system which has 5 to 60 aromatic ring atoms and is optionally substituted in each case by one or more R.sup.1 radicals, an aryloxy or heteroaryloxy group which has 5 to 60 aromatic ring atoms and is optionally substituted by one or more R.sup.1 radicals, an aralkyl or heteroaralkyl group which has 5 to 60 aromatic ring atoms and is optionally substituted by one or more R.sup.1 radicals, or a diarylamino group, diheteroarylamino group, or arylheteroarylamino group which has 10 to 40 aromatic ring atoms and is optionally substituted by one or more R.sup.1 radicals; the dotted lines represent bonds to adjacent structural units in the polymer; TABLE-US-00042 k is 0 or 1; m is 0, 1, 2, 3 or 4; n is 0, 1, 2 or 3; o is 0, 1 or 2; and q is 0, 1, 2, 3, 4, 5 or 6.

16. The composition of claim 13, wherein the crosslinkable Q group is selected from the group consisting of (1) terminal or cyclic alkenyl or terminal dienyl and alkynyl groups, (2) alkenyloxy, dienyloxy, or alkynyloxy groups, (3) acrylic acid groups, (4) oxetane and oxirane groups, (5) silane groups, and (6) cyclobutane groups.

17. The composition of claim 1, wherein the crosslinkable Q group is selected from: ##STR00408## ##STR00409## ##STR00410## wherein the R.sup.110, R.sup.120 and R.sup.130 radicals in the formulae Q1 to Q8, Q11, Q13 to Q20 and Q23 are the same or different at each instance and are H or a straight-chain or branched alkyl group having 1 to 6 carbon atoms; Ar.sup.10 in the formulae Q13 to Q 24 is a mono- or polycyclic, aromatic or heteroaromatic ring system which is optionally substituted by one or more R radicals; g is an integer from 0 to 8; h is an integer from 1 to 8; and the dotted bond in the formulae Q1 to Q11 and Q13 to Q23 and the dotted bonds in the formulae Q12 and Q24 denote the linkage of the crosslinkable group to one of the mono- or polycyclic, aromatic or heteroaromatic ring systems Ar.sup.1 to Ar.sup.3.

18. The composition of claim 1, wherein the proportion of structural units of formula (I) in the polymer is in the range from 1 to 100 mol %, based on 100 mol % of all copolymerized monomers present as structural units in the polymer.

19. The composition of claim 1, wherein the polymer, as well as structural units of the formula (I), comprises at least one further structural unit of formula (XIX) other than the structural units of formula (I):
-----Ar.sup.11-----(XIX) wherein Ar.sup.11 is a mono- or polycyclic, aromatic or heteroaromatic ring system optionally substituted by one or more R radicals.

20. The composition of claim 13, wherein the proportion of structural units of formula (I) having a crosslinkable Q group in the polymer is in the range from 0.1 to 50 mol %, based on 100 mol % of all copolymerized monomers present as structural units in the polymer.

21. The composition of claim 1, wherein the R.sup.12 radical in the formula (K1) is a mono- or polycyclic, aromatic or heteroaromatic ring system which has 5 to 60 aromatic ring atoms and is optionally substituted by an R radical.

22. The composition of claim 1, wherein, in formula (K1), the R.sup.11 radical is a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 40 carbon atoms or an alkenyl or alkynyl group having 2 to 40 carbon atoms or a branched or cyclic alkyl, alkoxy, or thioalkoxy group having 3 to 40 carbon atoms, each of which is optionally substituted by one or more R.sup.1 radicals, wherein one or more nonadjacent CH.sub.2 groups is optionally replaced by R.sup.1CCR.sup.1, CC, Si(R.sup.1).sub.2, CO, CS, CNR.sup.1, P(O)(R.sup.1), SO, SO.sub.2, NR.sup.1, O, S, or CONR.sup.1 and wherein one or more hydrogen atoms is optionally replaced by D, F, Cl, Br, I or CN, an aromatic or heteroaromatic ring system which has 5 to 60 aromatic ring atoms and is optionally substituted in each case by one or more R.sup.1 radicals, an aryloxy or heteroaryloxy group which has 5 to 60 aromatic ring atoms and is optionally substituted by one or more R.sup.1 radicals, an aralkyl or heteroaralkyl group which has 5 to 60 aromatic ring atoms and is optionally substituted by one or more R.sup.1 radicals, or a diarylamino group, diheteroarylamino group, or arylheteroarylamino group which has 10 to 40 aromatic ring atoms and is optionally substituted by one or more R.sup.1 radicals; and wherein two or more R radicals together optionally define a mono- or polycyclic, aliphatic, aromatic and/or benzofused ring system.

23. The composition of claim 1, wherein at least one of the R.sup.41, R.sup.42, R.sup.43 and R.sup.44 radicals in formula (A1) has at least one halogen atom as a substituent.

24. The composition of claim 1, wherein the E.sup.4 radical in formula (A1) is a boron atom.

25. The composition of claim 1, wherein the sum total of the ring atoms of the Ar.sup.4 radical together with the ring atoms of the Ar.sup.3 group bonded to said radical is at least 12.

26. The composition of claim 1, wherein the weight ratio of polymer to salt is in the range from 500:1 to 1:1.

27. A process for producing a composition according to claim 1, wherein a polymer having structural units of formula (I) is contacted with a salt comprising at least one cation of formula (K1) and at least one anion of formula (A1).

28. A solution or formulation comprising at least one composition according to claim 1 in one or more solvents.

29. The solution or formulation of claim 28, wherein the solvent is an ether and/or an ester.

30. An electronic or optoelectronic component having one or more active layers, wherein at least one of the one or more active layers comprises one or more compositions according to claim 1.

31. The electronic or optoelectronic component of claim 30, wherein the electronic or optoelectronic component is selected from the group consisting of organic electroluminescent devices, organic light-emitting electrochemical cells, organic field-effect transistors, organic integrated circuits, organic thin-film transistors, organic solar cells, organic laser diodes, organic photovoltaic elements, organic photovoltaic devices, and organic photoreceptors.

32. The electronic or optoelectronic component of claim 31, wherein the active layer comprising one or more compositions has been crosslinked.

33. The composition of claim 1, wherein the A.sup.1 radical of formula K.sup.1 is an element selected from the group consisting of Cl, Br, and I.

Description

EXAMPLES

(1) Part A: Synthesis of the Monomers

(2) The monomers for production of the inventive compositions are already described in the prior art, are commercially available or are prepared according to a literature method, and are summarized in the following table:

(3) TABLE-US-00032 Monomer Structure Synthesis according to Mo1 WO 2010/097155 A1 Mo2 WO 99/048160 A1 Mo3 Macromolecules 2000, 33, 2016-2020 Mo4 WO2013/156130 Mo5 WO2013/156130 Mo6 WO2013/156130 Mo7 WO2013/156130 (analogously to Mo14)

(4) Part B: Synthesis of the Polymers

(5) The comparative polymers V1 and V2 and the inventive polymers P1 to P6 are prepared by SUZUKI coupling by the process described in WO 2010/097155 from the monomers disclosed in Part A.

(6) The polymers V1 and V2 and P1 to P6 prepared in this way contain the structural units, after elimination of the leaving groups, in the percentages reported in Table 2 (percentages=mol %). In the case of the polymers which are prepared from monomers having aldehyde groups, the latter are converted to crosslinkable vinyl groups after the polymerization by WITTIG reaction by the process described in WO 2010/097155. The polymers listed correspondingly in Table 2 and used in Part C thus have crosslinkable vinyl groups rather than the aldehyde groups originally present.

(7) The palladium and bromine contents of the polymers are determined by ICP-MS. The values determined are below 10 ppm.

(8) The molecular weights Mw and the polydispersities D are determined by means of gel permeation chromatography (GPC) (model: Agilent HPLC System Series 1100, column: PL-RapidH from Polymer Laboratories; solvent: THF with 0.12% by volume of o-dichlorobenzene; detection: UV and refractive index; temperature: 40 C.). Calibration is effected with polystyrene standards.

(9) The results are collated in Table 2.

(10) TABLE-US-00033 TABLE 2 Molecular Triarylamine with ortho weight M.sub.W Polymer substituent Further monomers (g/mol) Polydisp. D V1 Mo2 50% Mo3 50% 438 000 3.3 V2 Mo2 40% Mo1 10% Mo3 50% 417 000 3.1 P1 Mo4 50% Mo3 50% 339 000 3.1 P2 Mo4 40% Mo3 50% Mo1 10% 328 000 2.9 P3 Mo4 50% Mo6 50% P4 Mo4 40% Mo6 50% Mo1 10% 123 000 3.3 P5 Mo4 40% Mo3 50% Mo5 10% 300 000 2.7 P6 Mo4 40% Mo7 50% Mo1 10%

(11) Part C: Dopants

(12) The dopants for production of the inventive compositions are already described in the prior art, are commercially available and are summarized in the following table:

(13) TABLE-US-00034 Dopant Structure CAS D1 178233-72-2 D2 0 136040-19-2

(14) Part D: Device Examples

(15) The inventive compositions, composed of polymer and salt, can be processed from solution and lead, compared to vacuum-processed OLEDs, to much more easily producible OLEDs having properties that are nevertheless good.

(16) Whether the crosslinkable variants of the inventive compositions (comprising crosslinkable polymers) after crosslinking give rise to a completely insoluble layer is tested analogously to WO 2010/097155.

(17) Table D1 lists the remaining layer thickness of the original 20 nm after the washing operation described in WO 2010/097155. If there is no decrease in the layer thickness, the composition of polymer and salt is insoluble and hence the crosslinking is sufficient.

(18) Table D1:

(19) Check of the residual layer thickness of the original 20 nm after the wash test

(20) TABLE-US-00035 Residual layer thickness Mass ratio of after wash test (in nm) Polymer Salt polymer:salt Crosslinking at 220 C. V1 D1 97:3 3.5 V2 D1 97:3 20 P2 D1 90:10 20 P4 D1 90:10 20 P6 D1 97:3 20

(21) As can be inferred from Table D1, the composition comprising comparative polymer V1 which does not bear any crosslinking group hardly crosslinks at all at 220 C. The compositions comprising comparative polymer V2 and the inventive polymers P2, P4 and P6, in contrast, crosslink completely at 220 C.

(22) There are already many descriptions of the production of such solution-based OLEDs in the literature, for example in WO 2004/037887 and WO 2010/097155. The process is matched to the circumstances described hereinafter (variation in layer thickness, materials).

(23) The inventive polymers are used in three different layer sequences:

(24) Structure A is as follows: substrate, ITO (50 nm), hole injection layer (HIL) (100 nm), cathode.

(25) Structure B is as follows: substrate, ITO (50 nm), HIL (20 nm), hole transport layer (HTL) (40 nm), emission layer (EML) (30 nm), electron transport layer (ETL) (20 nm), cathode.

(26) Structure C is as follows: substrate, ITO (50 nm), HIL (20 nm), HTL (20 nm), EML (60 nm), hole blocker layer (HBL) (10 nm), ETL (40 nm), cathode.

(27) Substrates used are glass plates coated with structured ITO (indium tin oxide) of thickness 50 nm. The hole injection, hole transport and emission layers are applied to these coated glass plates.

(28) The hole injection layers used are the inventive compositions, composed of polymer and salt, and comparative mixtures, each dissolved in toluene. The typical solids content of such solutions is about 5 to 15 g/l when layer thicknesses between 20 nm and 100 nm are 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. or 220 C. for 60 minutes.

(29) The hole transport layers in structure C are processed from toluene. The typical solids content of such solutions is about 5 g/l when layer thicknesses of 20 nm are 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. or 220 C. for 60 minutes.

(30) In structure B, the hole transport layer is formed by thermal evaporation in a vacuum chamber.

(31) The materials used in the present case are shown in Table D2.

(32) TABLE-US-00036 TABLE D2 Structural formula of the hole-transporting material processed from vacuum HT1

(33) The emission layer is always composed of at least one matrix material (host material) and an emitting dopant (emitter). In addition, mixtures of a plurality of matrix materials and co-dopants may occur. Details given in such a form as H1 (92%):dopant (8%) mean here that the material H1 is present in the emission layer in a proportion by weight of 92% and the dopant in a proportion by weight of 8%. The mixture for the emission layer is dissolved in toluene for structure C. The typical solids content of such solutions is about 18 g/l 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 at 180 C. for 10 minutes. In structure B, the emission layer is formed by thermal evaporation in a vacuum chamber. This layer 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 H3:dopant (95%:5%) mean here that the H3 and dopant materials are present in the layer in a proportion by volume of 95%:5%.

(34) The materials used in the present case are shown in Table D3.

(35) TABLE-US-00037 TABLE D3 Structural formulae of the materials used in the emission layer M1 M2 M3

(36) The materials for the hole blocker layer and electron transport layer are likewise applied by thermal vapour deposition in a vacuum chamber and are shown in Table D4. The hole blocker layer consists of ETM1. The electron transport layer consists of the two materials ETM1 and ETM2, which are added to one another by co-evaporation in a proportion by volume of 50% each.

(37) TABLE-US-00038 TABLE D4 HBL and ETL materials used ETM1 ETM2

(38) The cathode is formed by the thermal evaporation of an aluminium layer of thickness 100 nm.

(39) The exact structure of the OLEDs can be found in Table D5. The HTL column lists the polymer used, and the temperature at which the layer is baked and optionally crosslinked.

(40) TABLE-US-00039 TABLE D5 Structure of the OLEDs HIL HTL EML Struc- Mass ratio of T T Compo- Example ture Polymer Salt polymer:salt [ C.] Polymer [ C.] sition D1 B V1 D1 97:3 180 M3 95%; SEB 5% D2 C V2 D1 97:3 180 P2 180 C. M1 30%; M2 55%; TEG 15% D3 A P1 180 D4 A P1 D1 97:3 180 D5 A P3 180 D6 A P3 D1 97:3 180 D7 B P3 D1 97:3 180 M3 95%; SEB 5% D8 B P1 D1 97:3 180 M3 95%; SEB 5% D9 C P2 D1 97:3 180 P2 180 M1 30%; M2 55%; TEG 15% D10 C P4 D1 97:3 220 P2 180 M1 30%; M2 55%; TEG 15%

(41) 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, in the case of structures B and C, the (operating) lifetime are determined. The IUL characteristics are used to determine parameters such as the operating voltage (in V) and the external quantum efficiency (in %) at a particular brightness. LD80 @ 1000 cd/m.sup.2 is the lifetime until the OLED, given a starting brightness of 1000 cd/m.sup.2, has dropped to 80% of the starting intensity, i.e. to 800 cd/m.sup.2.

(42) The properties of the different OLEDs are summarized in Tables D6 a and b. Examples D1 and D2 are comparative examples; all the other examples show properties of inventive OLEDs.

(43) Tables D6 a-b:

(44) Properties of the OLEDs

(45) TABLE-US-00040 TABLE D6 a Voltage at 1 mA/cm.sup.2 Example [V] D3 6 D4 0.4 D5 3 D6 0.2

(46) TABLE-US-00041 TABLE D6 b Efficiency at Voltage at LD80 at 1000 cd/m.sup.2 1000 cd/m.sup.2 1000 cd/m.sup.2 Example % EQE [V] [h] D1 8.2 4.3 95 D2 16.6 4.8 240 D7 8.0 4.4 285 D8 8.3 4.2 320 D9 16.7 4.7 255 D10 16.5 4.3 278

(47) Table D6 a shows that the voltages of components made from inventive compositions (polymer and salt) are significantly lower than their equivalents without salt. The inventive mixtures are thus suitable as hole injection materials which lower the operating voltage of the OLED.

(48) Table D6 b shows that the use of the inventive mixtures leads to an improvement in lifetime over the prior art.