# US 2018/0323394 A1 · Organic electroluminescent device emitting blue light

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- Number: US 2018/0323394 A1
- Document ID: US20180323394A1
- Status: Published application
- Kind: A1
- Application number: 15/970,999
- Filed: 2018-05-04
- Published: 2018-11-08
- Earliest claimed: 2017-05-08
- Assignees: Cynora GmbH
- Applicants: Cynora GmbH
- Inventors: Andreas HALDI; Georgios LIAPTSIS; Harald FLUEGGE; Patrick PINGEL; Stefan HOEFLE
- Web page: https://patentgrep.com/patent/US20180323394A1

## CPC

- C09K 11/06: containing organic luminescent materials
- H10K 50/11: characterised by the electroluminescent [EL] layers
- H10K 50/12: comprising dopants
- H10K 50/121: {for assisting energy transfer, e.g. sensitization}
- H10K 50/125: specially adapted for multicolour light emission, e.g. for emitting white light
- H10K 85/654: {comprising only nitrogen as heteroatom (H10K85/652 takes precedence)}
- H10K 85/6572: {comprising only nitrogen in the heteroaromatic polycondensed ring system, e.g. phenanthroline or carbazole}
- H10K 50/15: Hole transporting layers
- H10K 50/16: Electron transporting layers
- H10K 2101/10: Triplet emission
- H10K 2101/20: Delayed fluorescence emission
- H10K 2101/30: Highest occupied molecular orbital [HOMO], lowest unoccupied molecular orbital [LUMO] or Fermi energy values
- H10K 2101/40: Interrelation of parameters between multiple constituent active layers or sublayers, e.g. HOMO values in adjacent layers
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES

## Abstract

The present invention relates to a an organic electroluminescent device comprising a light-emitting layer B comprising a host material HB, a first thermally activated delayed fluorescence (TADF) material EB, and a second TADF material SB, wherein SB transfers energy to EB and EB emits TADF with an emission maximum between 420 and 500 nm.

## Claims

### Claim at position 1

1-15. (canceled)

### Claim 16

An organic electroluminescent device comprising a light-emitting layer B comprising:
(i) a host material HB, which has a lowermost excited singlet state energy level S1H and a lowermost excited triplet state energy level T1H;
(ii) a first thermally activated delayed fluorescence (TADF) material EB, which has a lowermost excited singlet state energy level S1E and a lowermost excited triplet state energy level T1E; and
(iii) a second TADF material SB, which has a lowermost excited singlet state energy level S1S and a lowermost excited triplet state energy level T1S,
wherein SB transfers energy to EB and EB emits thermally activated delayed fluorescence with an emission maximum between 420 and 500 nm; and wherein the relations expressed by the following formulas (1) to (4) apply:
S1H<S1E (1)
S1H<S1S (2)
S1E<S1S (3)
T1H<T1S (4)

### Claim 17 (depends on 16)

The organic electroluminescent device according to claim 16, wherein said organic electroluminescent device is a device selected from the group consisting of an organic light emitting diode, a light emitting electrochemical cell, and a light-emitting transistor.

### Claim 18 (depends on 16)

The organic electroluminescent device according to claim 16, wherein the first TADF material EB is an organic TADF emitter.

### Claim 19 (depends on 16)

The organic electroluminescent device according to claim 16, wherein the second TADF material SB is an organic TADF emitter.

### Claim 20 (depends on 16)

The organic electroluminescent device according to claim 16, wherein the device exhibits an emission maximum λmax(D) of 440 to 470 nm.

### Claim 21 (depends on 16)

The organic electroluminescent device according to claim 16, wherein the light-emitting layer B comprises:
(i) 5-98% by weight of the host compound HB;
(ii) 1-50% by weight of the first TADF material EB; and
(iii) 1-50% by weight of the second TADF material SB; and optionally
(iv) 0-93% by weight of one or more further host compounds HB2 differing from HB; and optionally
(v) 0-93% by weight of one or more solvents.

### Claim 22 (depends on 16)

The organic electroluminescent device according to claim 16, wherein the second TADF material SB exhibits an emission maximum λmaxPMMA(SB) and the first TADF material EB exhibits an emission maximum λmaxPMMA(EB), wherein
500 nm≥λmaxPMMA(SB)>λmaxPMMA(EB).

### Claim 23 (depends on 16)

The organic electroluminescent device according to claim 16, wherein the first TADF material EB exhibits an emission maximum λmaxPMMA(EB) in the range of from 450 to 470 nm.

### Claim 24 (depends on 16)

The organic electroluminescent device according to claim 16, wherein the second TADF material SB exhibits an emission maximum λmaxPMMA(SB), the first TADF material EB exhibits an emission maximum λmaxPMMA(EB) and the device exhibits an emission maximum λmax(D), wherein
λmaxPMMA(SB)>λmax(D)≥λmaxPMMA(EB).

### Claim 25 (depends on 16)

The organic electroluminescent device according to claim 16, wherein T1E>T1S.

### Claim 26 (depends on 16)

The organic electroluminescent device according to claim 16, wherein
S1E<S1S≥T1E<T1S and
S1E−T1S≤0.4 eV.

### Claim 27 (depends on 16)

The organic electroluminescent device according to claim 16, wherein first TADF material EB and the second TADF material SB are independently from another both chosen from molecules of a structure of Formula I
wherein
n is at each occurrence independently from another 1 or 2;
X is at each occurrence independently from another CN or CF3;
Z is at each occurrence independently from another selected from the group consisting of a direct bond, CR3R4, C═CR3R4, C═O, C═NR3, NR3, O, SiR3R4, S, S(O), and S(O)2;
ArEWG is at each occurrence independently from another a structure according to one of Formulae IIa to IIi
wherein # represents the binding site of the single bond linking ArEWG to the substituted central phenyl ring of Formula I;
R1 is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, C1-C5-alkyl, wherein one or more hydrogen atoms are optionally substituted by deuterium, and C6-C18-aryl, which is optionally substituted with one or more substituents R6;
R2 is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, C1-C5-alkyl, wherein one or more hydrogen atoms are optionally substituted by deuterium, and C6-C18-aryl, which is optionally substituted with one or more substituents R6;
Ra, R3, and R4 is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, N(R5)2, ORS, SRS, Si(R5)3, CF3, CN, F,
C1-C40-alkyl, which is optionally substituted with one or more substituents R5 and wherein one or more non-adjacent CH2-groups are optionally substituted by R5C═CR5, C≡C, Si(R5)2, Ge(R5)2, Sn(R5)2, C═O, C═S, C═Se, C═NR5, P(═O)(R5), SO, SO2, NR5, O, S, or CONR5;
C1-C40-thioalkoxy, which is optionally substituted with one or more substituents R5 and wherein one or more non-adjacent CH2-groups are optionally substituted by R5C═CR5, C≡C, Si(R5)2, Ge(R5)2, Sn(R5)2, C═O, C═S, C═Se, C═NR5, P(═O)(R5), SO, SO2, NR5, O, S, or CONR5;
C6-C60-aryl, which is optionally substituted with one or more substituents R5; and
C3-C57-heteroaryl, which is optionally substituted with one or more substituents R5;
R5 is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, N(R6)2, OR6, SR6, Si(R6)3, CF3, CN, F,
C1-C40-alkyl, which is optionally substituted with one or more substituents R6 and wherein one or more non-adjacent CH2-groups are optionally substituted by R6C═CR6, C≡C, Si(R6)2, Ge(R6)2, Sn(R6)2, C═O, C═S, C═Se, C═NR6, P(═O)(R6), SO, SO2, NR6, O, S, or CONR6;
C6-C60-aryl, which is optionally substituted with one or more substituents R6; and
C3-C57-heteroaryl, which is optionally substituted with one or more substituents R6;
R6 is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, OPh,CF3, CN, F,
C1-C5-alkyl, wherein one or more hydrogen atoms are optionally, independently from each other, substituted by deuterium, CN, CF3, or F;
C1-C5-alkoxy, wherein one or more hydrogen atoms are optionally, independently from each other, substituted by deuterium, CN, CF3, or F;
C1-C5-thioalkoxy, wherein one or more hydrogen atoms are optionally, independently from each other, substituted by deuterium, CN, CF3, or F;
C6-C18-aryl, which is optionally substituted with one or more C1-C5-alkyl substituents;
C3-C17-heteroaryl, which is optionally substituted with one or more C1-C5-alkyl substituents;
N(C6-C18-aryl)2;
N(C3-C17-heteroaryl)2; and
N(C3-C17-heteroaryl)(C6-C18-aryl);
Rd is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, N(R5)2, ORS, SRS, Si(R5)3, CF3, CN, F,
C1-C40-alkyl, which is optionally substituted with one or more substituents R5 and wherein one or more non-adjacent CH2-groups are optionally substituted by R5C═CR5, C≡C, Si(R5)2, Ge(R5)2, Sn(R5)2, C═O, C═S, C═Se, C═NR5, P(═O)(R5), SO, SO2, NR5, O, S, or CONR5;
C1-C40-thioalkoxy, which is optionally substituted with one or more substituents R5 and wherein one or more non-adjacent CH2-groups are optionally substituted by R5C═CR5, C≡C, Si(R5)2, Ge(R5)2, Sn(R5)2, C═O, C═S, C═Se, C═NR5, P(═O)(R5), SO, SO2, NR5, O, S, or CONR5;
C6-C60-aryl, which is optionally substituted with one or more substituents R5; and
C3-C57-heteroaryl which is optionally substituted with one or more substituents R5;
wherein the substituents Ra, R3, R4, or R5 independently from each other optionally may form a mono- or polycyclic, aliphatic, aromatic, and/or benzo-fused ring system with one or more substituents Ra, R3, R4, or R5, and
wherein the one or more substituents Rd independently from each other optionally may form a mono- or polycyclic, aliphatic, aromatic, and/or benzo-fused ring system with one or more substituents Rd.

### Claim 28 (depends on 27)

The organic electroluminescent device according to claim 27, wherein the first TADF material EB and the second TADF material SB both bear the same structure according to Formula I structurally only differing in one or more of Ra, R1, R2, and X.

### Claim 29 (depends on 27)

The organic electroluminescent device according to claim 27, wherein Z is a direct bond at each occurrence.

### Claim 30 (depends on 27)

The organic electroluminescent device according to claim 27, wherein Ra is at each occurrence independently from another selected from the group consisting of
hydrogen, deuterium, Me, iPr, tBu, CN, CF3,
Ph, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, iPr, tBu, CN, CF3, and Ph;
pyridinyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, iPr, tBu, CN, CF3, and Ph;
pyrimidinyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, iPr, tBu, CN, CF3, and Ph;
carbazolyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, iPr, tBu, CN, CF3, and Ph;
triazinyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, iPr, tBu, CN, CF3, and Ph; and
N(Ph)2.

### Claim 31 (depends on 16)

The organic electroluminescent device according to claim 16, wherein the second TADF material SB exhibits an emission maximum λmaxPMMA(SB) and the first TADF material EB exhibits an emission maximum λmaxPMMA(EB), wherein
480 nm≥λmaxPMMA(SB)>λmaxPMMA(EB).