Electronic device

Abstract

The present application relates to an electronic device having defined composition of the emitting layer. The application furthermore relates to the use of the device in displays or in lighting applications.

Claims

1. An electronic device comprising an anode, a cathode, and at least one emitting layer, wherein the emitting layer comprises at least one dopant D, wherein the D is a fluorescent emitting compound, at least one matrix material M1, and at least one matrix material M2, wherein the D, the M1, and the M2 are different, wherein the M1 is a monotriarylamine selected from the group consisting of formulae (I-2) through (I-4): ##STR00084## wherein Z is on each occurrence, identically or differently, N or CR.sup.1, wherein Z is C if a substituent is bonded; X is on each occurrence, identically or differently, a single bond, O, S, Se, BR.sup.1, C(R.sup.1).sub.2, Si(R.sup.1).sub.2, NR.sup.1, PR.sup.1, C(R.sup.1).sub.2-C(R.sup.1).sup.2, or CR.sup.1=CR.sup.1; Y is a single bond, O, S, Se, BR.sup.1, C(R.sup.1).sub.2, Si(R.sup.1).sup.2, NR.sup.1, PR.sup.1, C(R.sup.1).sub.2-C(R.sup.1).sup.2, or CR.sup.1=CR.sup.1; Ar.sup.1 is on each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 50 aromatic ring atoms, which is optionally substituted by one or more radicals R.sup.1; R.sup.1 is on each occurrence, identically or differently, H, D, F, C(═O)R.sup.2, CN, Si(R.sup.2).sub.3, P(═O)(R.sup.2).sub.2, S(═O)R.sup.2, S(═O).sub.2R.sup.2, a straight-chain alkyl or alkoxy group having 1 to 20 C atoms or a branched or cyclic alkyl or alkoxy group having 3 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms, wherein the above-mentioned groups are optionally substituted by one or more radicals R.sup.2 and wherein one or more CH.sub.2 groups in the above-mentioned groups are optionally replaced by —R.sup.2C═CR.sup.2—, —C≡C—, Si(R.sup.2).sub.2, C═O, C═S, C═NR.sup.2, —C(═O)O—, —C(═O)NR.sup.2—, P(═O)(R.sup.2), —O—, —S—, SO, or SO.sub.2 and wherein one or more H atoms in the above-mentioned groups is optionally replaced by D, F or CN, or an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, which in each case is optionally substituted by one or more radicals R.sup.2, or an aryloxy or heteroaryloxy group having 5 to 30 aromatic ring atoms, which is optionally substituted by one or more radicals R.sup.2; R.sup.2 is on each occurrence, identically or differently, H, D, F, or an aliphatic, aromatic, or heteroaromatic organic radical having 1 to 20 C atoms, wherein one or more H atoms are optionally replaced by D or F; p is 0 or 1 and m and n are, identically or differently, 0 or 1, wherein the sum of m and n is equal to 1 or 2; and wherein M2 is a compound of formula (II-1): ##STR00085## wherein the benzanthracenyl group is bonded to the anthracene in positions 1, 2, 3, 4, 5, or 6 and the benzanthracene and the anthracene are optionally substituted at all free positions by a group R.sup.3; Ar.sup.4 is on each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, which is optionally substituted by one or more radicals R.sup.3; R.sup.3 is on each occurrence, identically or differently, H, D, F, C(═O)R.sup.4, CN, Si(R.sup.4).sub.3, N(R.sup.4).sub.2, P(═O)(R.sup.4).sub.2, S(═O)R.sup.4, S(═O).sub.2R.sup.4, a straight-chain alkyl or alkoxy group having 1 to 20 C atoms or a branched or cyclic alkyl or alkoxy group having 3 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms, wherein the above-mentioned groups are each optionally substituted by one or more radicals R.sup.4 and wherein one or more CH.sub.2 groups in the above-mentioned groups are optionally replaced by —R.sup.4C═CR.sup.4—, —C≡C—, Si(R.sup.4).sub.2, C═O, C═S, C═NR.sup.4, —C(═O)O—, —C(═O)NR.sup.4—, NR.sup.4, P(═O)(R.sup.4), —O—, —S—, SO, or SO.sub.2 and wherein one or more H atoms in the above-mentioned groups are optionally replaced by D, F, or CN, or an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, which in each case is optionally substituted by one or more radicals R.sup.4, or an aryloxy or heteroaryloxy group having 5 to 30 aromatic ring atoms, which is optionally substituted by one or more radicals R.sup.4, and wherein two or more radicals R.sup.3 are optionally linked to one another so as to define a ring; R.sup.4 is on each occurrence, identically or differently, H, D, F, or an aliphatic, aromatic or heteroaromatic organic radical having 1 to 20 C atoms, in which, in addition, one or more H atoms may be replaced by D or F; two or more substituents R.sup.4 here may be linked to one another and may form a ring.

2. The electronic device of claim 1, wherein the emitting layer of the device emits light having an emission maximum at a wavelength of 430 nm to 480 nm.

3. The electronic device of claim 1, wherein a hole-transporting layer comprising one or more monotriarylamine compounds is present on the anode side of the emitting layer.

4. The electronic device of claim 1, wherein the D is present in the emitting layer in a proportion of 0.5 to 10% by volume.

5. The electronic device of claim 1, wherein the M1 is present in the emitting layer in a proportion of 1 to 15% by volume.

6. The electronic device of claim 1, wherein the Ar.sup.1 contains no condensed aryl or heteroaryl group having more than 10 aromatic ring atoms.

7. The electronic device of claim 1, wherein the electronic device is selected from the group consisting of organic integrated circuits, organic field-effect transistors, organic thin-film transistors, organic light-emitting transistors, organic solar cells, organic optical detectors, organic photoreceptors, organic field-quench devices, organic light-emitting electrochemical cells, organic laser diodes, and organic electroluminescent devices.

8. The electronic device of claim 1, wherein the emitting layer is applied from solution.

9. A display, a light source in lighting applications, or a light source in medical and/or cosmetic applications comprising the electronic device of claim 1.

10. A formulation comprising at least one organic solvent, at least one dopant D, wherein the D is a fluorescent emitting compound, at least one matrix material M1, and at least one matrix material M2, wherein the D, the M1, and the M2 are different, and wherein the M1 is a monotriarylamine selected from the group consisting of formulae (I-2) through (I-4): ##STR00086## wherein Z is on each occurrence, identically or differently, N or CR.sup.1, wherein Z is C if a substituent is bonded; X is on each occurrence, identically or differently, a single bond, O, S, Se, BR.sup.1, C(R.sup.1).sub.2, Si(R.sup.1).sub.2, NR.sup.1, PR.sup.1, C(R.sup.1).sub.2-C(R.sup.1).sub.2, or CR.sup.1═CR.sup.1; Y is a single bond, O, S, Se, BR.sup.1, C(R.sup.1).sub.2, Si(R.sup.1).sub.2, NR.sup.1, PR.sup.1, C(R.sup.1).sub.2-C(R.sup.1).sub.2, or CR.sup.1═CR.sup.1. Ar.sup.1 is on each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 50 aromatic ring atoms, which is optionally substituted by one or more radicals R.sup.1; R.sup.1 is on each occurrence, identically or differently, H, D, F, C(═O)R.sup.2, CN, Si(R.sup.2).sub.3, P(═O)(R.sup.2).sub.2, S(═O)R.sup.2, S(═O).sub.2R.sup.2, a straight-chain alkyl or alkoxy group having 1 to 20 C atoms or a branched or cyclic alkyl or alkoxy group having 3 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms, wherein the above-mentioned groups are optionally substituted by one or more radicals R.sup.2, and wherein one or more CH.sub.2 groups in the above-mentioned groups are optionally replaced by —R.sup.2C═CR.sup.2—, —C≡C—, Si(R.sup.2).sub.2, C═O, C═S, C═NR.sup.2, —C(═O)O—, —C(═O)NR.sup.2—, P(═O)(R.sup.2), —O—, —S—, SO, or SO.sub.2, and wherein one or more H atoms in the above-mentioned groups is optionally replaced by D, F, or CN, an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, which is each case is optionally substituted by one or more radicals R.sup.2, or an aryloxy or heteroaryloxy group having 5 to 30 aromatic ring atoms, which is optionally substituted by one or more radicals R.sup.2; R.sup.2 is on each occurrence, identically or differently, H, D, F, or an aliphatic, aromatic, or heteroaromatic organic radical having 1 to 20 C atoms, wherein one or more H atoms are optionally replaced by D or F; p is 0 or 1; and m and n are, identically or differently, 0 or 1, wherein the sum of m and n is equal to 1 or 2; and wherein M2 is a compound of formula (II-1): ##STR00087## wherein the benzanthracenyl group is bonded to the anthracene in positions 1, 2, 3, 4, 5, or 6 and the benzanthracene and the anthracene are optionally substituted at all free positions by a group R.sup.3; Ar.sup.4 is on each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, optionally substituted by one or more radicals R.sup.3; R.sup.3 is on each occurrence, identically or differently, H, D, F, C(═O)R.sup.4, CN, Si(R.sup.4).sub.3, N(R.sup.4).sub.2, P(═O)(R.sup.4).sub.2, S(═O)R.sup.4, S(═O).sub.2R.sup.4, a straight-chain alkyl or alkoxy group having 1 to 20 C atoms or a branched or cyclic alkyl or alkoxy group having 3 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms, wherein the above-mentioned groups are optionally substituted by one or more radicals R.sup.4, and wherein one or more CH.sub.2 groups in said groups are optionally replaced by —R.sup.4C═CR.sup.4—, —C≡C—, Si(R.sup.4).sub.2, C═O, C═S, C═NR.sup.4, —C(═O)O—, —C(═O)NR.sup.4—, NR.sup.4, P(═O)(R.sup.4), —O—, —S—, SO, or SO.sub.2, and wherein one or more H atoms in the above-mentioned groups are optionally replaced by D, F, or CN, or an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, which is each case is optionally substituted by one or more radicals R.sup.4, or an aryloxy or heteroarloxy group having 5 to 30 aromatic ring atoms, which is optionally substituted by one or more radicals R.sup.4, and wherein two or more radicals R.sup.3 are optionally linked to one another so as it define a ring; R.sup.4 is on each occurrence, identically or differently, H, D, F, or an aliphatic, aromatic, or heteroaromatic organic radical having 1 to 20 C atoms, in which, in addition, one or more H atoms is optionally replaced by D or F; two or more substituents R.sup.4 here may be linked to one another and may form a ring.

11. An organic electroluminescent device comprising the formulation of claim 10.

Description

WORKING EXAMPLES

A) Production of the OLEDs

(1) The results of various OLEDs are presented in the following Examples V1 to V7 and E1 to E7 (see Table 1 for structure of the device and Table 2 for data of the device). E denotes examples according to the invention, V denotes comparative examples.

(2) Glass plates coated with structured ITO (indium tin oxide) in a thickness of 50 nm are wet-cleaned (dishwasher, Merck Extran detergent). For the HTL layer arrangements B and C (see below), these glass plates are treated with a UV ozone plasma, and, for improved processing, a 20 nm PEDOT: PSS layer is applied (poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate), purchased as CLEVIOS™ P VP AI 4083 from Heraeus Clevios Deutschland, applied by spin coating from aqueous solution). For the HTL layer arrangement A, the glass plates are dried by heating at 250° C. for 15 min before application of the organic layers by vapour deposition and subsequently treated with an oxygen plasma.

(3) The glass plates form the substrates to which the OLEDs are applied. The OLEDs have in principle the following layer structure: substrate/HTL layer arrangement/emission layer (EML)/electron-transport layer (ETL)/optional electron-injection layer (EIL) and finally a cathode. The cathode is formed by an aluminium layer with a thickness of 100 nm. The precise structure of the OLEDs is shown in Table 1. The materials required for the production of the OLEDs are shown in Table 3.

(4) The HTL layer arrangement A consists, viewed from the substrate, of a 90 nm thick layer of material SpA2, 10 nm of HATCN, 30 nm of SpA2, 10 nm of HATCN and 20 nm of MA1.

(5) The HTL layer arrangement B consists analogously of 140 nm of SpA1, 5 nm of HATCN and 20 nm of CbzA1.

(6) The HTL layer arrangement C consists analogously of 140 nm of SpA1, 5 nm of HATCN and 20 nm of MA1.

(7) All materials are applied by thermal vapour deposition in a vacuum chamber. The emission layer here always consists of at least one matrix material (host material) and an emitting dopant (emitter), which is admixed with the matrix material or matrix materials in a certain proportion by volume by coevaporation. An expression such as M1:CbzA1:D1 (89%:8%:3%) here means that the material M1 is present in the layer in a proportion by volume of 89%, CbzA1 is present in the layer in a proportion of 8% and D1 is present in the layer in a proportion of 3%.

(8) The OLEDs are characterised by standard methods. For this purpose, the electroluminescence spectra, the current efficiency (measured in cd/A), the power efficiency (measured in Im/W) and the external quantum efficiency (EQE, measured in percent) as a function of the luminous density, calculated from current/voltage/luminous density characteristic lines (IUL characteristic lines) assuming Lambert emission characteristics, and the lifetime are determined. The electroluminescence spectra are determined at a luminous density of 1000 cd/m.sup.2, and the CIE 1931 x and y colour coordinates are calculated therefrom. The expression U1000 in Table 2 denotes the voltage necessary for a luminous density of 1000 cd/m.sup.2. CE1000 and PE1000 denote the current and power efficiency respectively which are achieved at 1000 cd/m.sup.2. Finally, EQE1000 denotes the external quantum efficiency at an operating luminous density of 1000 cd/m.sup.2. The lifetime LT is defined as the time after which the luminous density drops from the initial luminous density L0 to a certain proportion L1 on operation at constant current. An expression of L0=6000 cd/m.sup.2 and L1=70% in Table 2 means that the lifetime indicated in column LT corresponds to the time after which the initial luminous density drops from 6000 cd/m.sup.2 to 4200 cd/m.sup.2.

(9) The data of the various OLEDs are summarised in Table 2. Example V1-V7 are comparative examples in accordance with the prior art, Examples E1-E7 show data of OLEDs having a structure according to the invention.

(10) As can be seen from the table, significantly better values for voltage, but in particular also efficiency and lifetime, are obtained with triarylmonoamines (compounds MA1 and MA2) as additional component in the emission layer compared with amine compounds containing two or more arylamine groups (compounds CbzA1, SpA1, NPB).

(11) This effect is achieved with various dopants, as shown by the examples with various dopants (amine-free pyrene emitter, monobenzoindenofluorenamine D2, perylene derivative TBP).

(12) TABLE-US-00001 TABLE 1 Structure of the OLEDs HTL EML ETL EIL Ex. stack Thickness Thickness Thickness V1 A M1:CbzA1:D1 ST1:LiQ (50%:50%) — (89%:8%:3%) 30 nm 20 nm V2 B M1:CbzA1:D2 ST1:LiQ (50%:50%) LiQ (90%:5%:5%) 20 nm 1 nm 30 nm V3 B M1:SpA1:D2 ST1:LiQ (50%:50%) LiQ (90%:5%:5%) 20 nm 1 nm 30 nm V4 C M1:CbzA1:D2 ST1:LiQ (50%:50%) LiQ (90%:5%:5%) 20 nm 1 nm 30 nm V5 C M1:SpA1:D2 ST1:LiQ (50%:50%) LiQ (90%:5%:5%) 20 nm 1 nm 30 nm V6 C M1:NPB:D2 ST1:LiQ (50%:50%) LiQ (90%:5%:5%) 20 nm 1 nm 30 nm V7 C M1:NPB:TBP ST1:LiQ (50%:50%) LiQ (91%:7%:2%) 20 nm 1 nm 30 nm E1 A M1:MA1:D1 ST1:LiQ (50%:50%) — (89%:8%:3%) 30 nm 20 nm E2 B M1:MA1:D2 ST1:LiQ (50%:50%) LiQ (90%:5%:5%) 20 nm 1 nm 30 nm E3 B M1:MA2:D2 ST1:LiQ (50%:50%) LiQ (90%:5%:5%) 20 nm 1 nm 30 nm E4 C M1:MA1:D2 ST1:LiQ (50%:50%) LiQ (90%:5%:5%) 20 nm 1 nm 30 nm E5 C M1:MA2:D2 ST1:LiQ (50%:50%) LiQ (90%:5%:5%) 20 nm 1 nm 30 nm E6 C M1:MA1:TBP ST1:LiQ (50%:50%) LiQ (91%:7%:2%) 20 nm 1 nm 30 nm E7 C M1:MA2:TBP ST1:LiQ (50%:50%) LiQ (91%:7%:2%) 2 nm 1 nm 30 nm

(13) TABLE-US-00002 TABLE 2 Data of the OLEDs U1000 CE1000 PE1000 EQE CIE x/y at L1 LT Ex. (V) (cd/A) (lm/W) 1000 1000 cd/m.sup.2 L0 % (h) V1 5.5 6.3 3.6 6.3% 0.14/011 6000 70 140 cd/m.sup.2 V2 4.5 8.0 5.6 7.4% 0.14/0.13 6000 70 170 cd/m.sup.2 V3 4.8 5.7 3.7 4.2% 0.15/0.18 6000 70 60 cd/m.sup.2 V4 4.4 8.4 6.0 7.7% 0.14/0.13 6000 70 180 cd/m.sup.2 V5 4.8 6.0 4.0 4.5% 0.15/0.17 6000 70 55 cd/m.sup.2 V6 4.2 7.5 5.5 6.8% 0.15/0.14 6000 70 150 cd/m.sup.2 V7 4.5 9.2 4.5 6.0% 0.14/0.21 6000 70 130 cd/m.sup.2 E1 5.3 6.6 3.9 6.9% 0.15/0.10 6000 70 200 cd/m.sup.2 E2 4.5 8.6 6.1 7.9% 0.14/0.13 6000 70 190 cd/m.sup.2 E3 4.5 8.5 5.9 7.8% 0.14/0.13 6000 70 185 cd/m.sup.2 E4 4.4 8.6 6.1 8.0% 0.14/0.13 6000 70 220 cd/m.sup.2 E5 4.3 8.7 6.3 8.1% 0.14/0.13 6000 70 235 cd/m.sup.2 E6 4.3 10 7.2 6.7% 0.14/0.20 6000 70 180 cd/m.sup.2 E7 4.4 9.9 7.1 6.9% 0.14/0.20 6000 70 195 cd/m.sup.2

(14) TABLE-US-00003 TABLE 3 Structural formulae of the materials for the OLEDs HATCN SpA1 NPB SpA2 M1 D1 D2 CbzA1 ST1 0 LiQ TBP MA1 MA2