Organic electroluminescent device emitting visible light

Patent metadata

Field	Value
Publication number	US-2022352468-A1
Application number	US-202017762194-A
Country	US
Kind code	A1
Filing date	Oct 13, 2020
Priority date	Oct 14, 2019
Publication date	Nov 3, 2022
Grant date	—

Abstract

The invention relates to an organic electroluminescent device comprising a light-emitting layer B comprising a host material HB, a thermally activated delayed fluorescence (TADF) material EB, and a depopulation agent SB.

First claim

1 - 16 . (canceled)

17 . An organic electroluminescent device comprising a light-emitting layer B comprising:
(i) a host material H B , which has a lowermost excited singlet state energy level S1 H , a lowermost excited triplet state energy level T1 H , and a highest occupied molecular orbital HOMO(H B ) having an energy E HOMO (H B ); (ii) a thermally activated delayed fluorescence (TADF) material E B , which has a lowermost excited singlet state energy level S1 E , a lowermost excited triplet state energy level T1 E , and a highest occupied molecular orbital HOMO(E B ) having an energy E HOMO (E B ); and (iii) a depopulation agent S B , which has a lowermost excited singlet state energy level S1 S , optionally a lowermost excited triplet state energy level T1 S , and a highest occupied molecular orbital HOMO(S B ) having an energy E HOMO (S B ); wherein E B emits thermally activated delayed fluorescence; and wherein the relations expressed by the following formulas (1) to (3) and either (4a) and (4b), or (5a) and (5b) apply:
S 1 H >S 1 E   (1)

S 1 H >S 1 S   (2)

S 1 S >S 1 E   (3)

E HOMO ( E B )≤ E HOMO ( H B )  (4a)

0.2 eV≤ E HOMO ( S B )− E HOMO ( E B )≤0.8 eV  (4b)

E HOMO ( H B )≥ E HOMO ( E B )  (5a)

0.2 eV≤ E HOMO ( S B )− E HOMO ( H B )≤0.8 eV  (5b).

18 . The organic electroluminescent device according to claim 17 , wherein the TADF material E B has a ΔE ST value, which corresponds to the energy difference between S1 E and T1 E , of less than 0.4 eV.

19 . The organic electroluminescent device according to claim 17 , wherein the mass ratio of the TADF material E B to depopulation agent S B (E B :S B ) is >1.

20 . The organic electroluminescent device according to claim 17 , wherein the organic electroluminescent device is selected from the group consisting of an organic light emitting diode, a light emitting electrochemical cell, and a light-emitting transistor.

21 . The organic electroluminescent device according to claim 17 , wherein the TADF material E B is an organic TADF emitter or a combination of two or more organic TADF emitters.

22 . The organic electroluminescent device according to claim 17 , wherein the depopulation agent S B is an organic TADF emitter or a combination of two or more organic TADF emitters.

23 . The organic electroluminescent device according to claim 17 , wherein the relation between the lowest unoccupied molecular orbital LUMO(E B ) of the TADF material E B having an energy E LUMO (E B ) and the lowest unoccupied molecular orbital LUMO(S B ) of the depopulation agent S B having an energy E LUMO (S B ) expressed by formula (7) applies:
E LUMO ( S B )> E LUMO ( E B )  (7).

24 . The organic electroluminescent device according to claim 17 , wherein a relation expressed by formula (6a), (6b), or (6c) applies:
E HOMO ( E B )> E HOMO ( H B )  (6a)
E HOMO ( H B )> E HOMO ( E B )  (6b)
−0.2 eV≤ E HOMO ( H B )− E HOMO ( E B )≤0.2 eV  (6c).

25 . The organic electroluminescent device according to claim 17 , wherein the light-emitting layer B comprises:
(i) 39.8-98% by weight of the host compound H B ; (ii) 0.1-50% by weight of the TADF material E B ; and (iii) 0.1-50% by weight of depopulation agent S B ; and optionally (iv) 0-60% by weight of one or more further host compounds H B2 differing from H B ; and optionally (v) 0-60% by weight of one or more solvents; and optionally (vi) 0-30% by weight of at least one further emitter molecule F.

26 . The organic electroluminescent device according to claim 17 , wherein the light-emitting layer B comprises 1-8% by weight of the depopulation agent S B .

27 . The organic electroluminescent device according to claim 17 , wherein the depopulation agent S B has a ΔE ST value, which corresponds to the energy difference between S1 S and T1 S , of less than 0.4 eV.

28 . The organic electroluminescent device according to claim 17 , wherein the TADF emitter E B and/or the depopulation agent S B comprises or consists of a structure according to Formula I-TADF

wherein:
is at each occurrence independently from another 1 or 2;
p is at each occurrence independently from another 1 or 2;
X is at each occurrence independently from another selected from the group consisting of Ar EWG H, CN, and CF 3 ;
Z is at each occurrence independently from another selected from the group consisting of a direct bond, CR 3 R 4 , C═CR 3 R 4 , C═O, C═NR 3 , NR 3 , O, SiR 3 R 4 , S, S(O), and S(O) 2 ;
Ar EWG is at each occurrence independently from another a structure according to one of Formulas IIa to IIk

wherein # represents the binding site of the single bond linking Ar EWG to the substituted central phenyl ring of Formula I-TADF;
R 1 is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, C 1 -C 5 -alkyl, wherein one or more hydrogen atoms are optionally substituted by deuterium, and C 6 -C 18 -aryl, which is optionally substituted with one or more substituents R 6 ;
R 2 is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, C 1 -C 5 -alkyl, wherein one or more hydrogen atoms are optionally substituted by deuterium, and C 6 -C 18 -aryl, which is optionally substituted with one or more substituents R 6 ;
R a , R 3 , and R 4 are at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, N(R 5 ) 2 , OR 5 ,
SR 5 , Si(R 5 ) 3 , CF 3 , CN, F,
C 1 -C 40 -alkyl, which is optionally substituted with one or more substituents R 5 and wherein one or more non-adjacent CH 2 -groups are optionally substituted by R 5 C═CR 5 , C≡C, Si(R 5 ) 2 , Ge(R 5 ) 2 , Sn(R 5 ) 2 , C═O, C═S, C═Se, C═NR 5 , P(═O)(R 5 ), SO, SO 2 , NR 5 , O, S, or CONR 5 ;
C 1 -C 40 -thioalkoxy, which is optionally substituted with one or more substituents R 5 and wherein one or more non-adjacent CH 2 -groups are optionally substituted by R 5 C═CR 5 , C≡C, Si(R 5 ) 2 , Ge(R 5 ) 2 , Sn(R 5 ) 2 , C═O, C═S, C═Se, C═NR 5 , P(═O)(R 5 ), SO, SO 2 , NR 5 , O, S, or CONR 5 ;
C 6 -C 60 -aryl, which is optionally substituted with one or more substituents R 5 ; and
C 3 -C 57 -heteroaryl, which is optionally substituted with one or more substituents R 5 ;
R 5 is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, N(R 6 ) 2 , OR 6 , SR 6 , Si(R 6 ) 3 , CF 3 , CN, F,
C 1 -C 40 -alkyl, which is optionally substituted with one or more substituents R 6 and wherein one or more non-adjacent CH 2 -groups are optionally substituted by R 6 C═CR 6 , C≡C, Si(R 6 ) 2 , Ge(R 6 ) 2 , Sn(R 6 ) 2 , C═O, C═S, C═Se, C═NR 6 , P(═O)(R 6 ), SO, SO 2 , NR 6 , O, S, or CONR 6 ;
C 6 -C 60 -aryl, which is optionally substituted with one or more substituents R 6 ; and
C 3 -C 57 -heteroaryl, which is optionally substituted with one or more substituents R 6 ;
R 6 is at each occurrence independently from another selected from the group consisting of hydrogen, deuterium, OPh, CF 3 , CN, F,
C 1 -C 5 -alkyl, wherein one or more hydrogen atoms are option

Assignees

• Cynora Gmbh

Inventors

• Sharifidehsari Hamed
• Koch Federico
• Liaptsis Georgios
• Carballo Jaime Leganes
• Kasparek Christian

Classifications

• C09K11/06

  containing organic luminescent materials · CPC title

• C09K2211/1018

  Heterocyclic compounds · CPC title

• H01L51/0067

  Electricity · mapped topic

• H01L51/0072

  Electricity · mapped topic

• H01L51/008 Primary

  Electricity · mapped topic