Fluorescent organic light emitting elements having high efficiency

Patent metadata

Field	Value
Publication number	US-10135004-B2
Application number	US-201715846655-A
Country	US
Kind code	B2
Filing date	Dec 19, 2017
Priority date	Apr 4, 2014
Publication date	Nov 20, 2018
Grant date	Nov 20, 2018

Abstract

The present invention relates to organic light emitting elements, comprising thermally activated delayed fluorescence (TADF) emitters and/or hosts on basis of benzotriazoles, which have a sufficiently small energy gap between S1 and T1 (ΔEST) to enable up-conversion of the triplet exciton from T1 to S1. The organic light emitting elements show high electroluminescent efficiency.

First claim

The invention claimed is:

1. An organic light-emitting element, comprising a light-emitting layer comprising
i) a compound of formula

as guest and a host material; or
ii) a compound of formula

as host and a fluorescent guest material, wherein
R 1 , R 2 , R 3 and R 4 are independently of each other H, D, F, Cl, a C 1 -C 25 alkyl group, a C 1 -C 25 alkoxy group, a C 6 -C 10 aryloxy group, or a donor group of formula

R 5 , R 6 , R 7 , R 8 and R 9 are independently of each other H, D, F, Cl, a C 1 -C 25 alkyl group, a C 1 -C 25 alkoxy group, a C 6 -C 10 aryloxy group, a group of formula

(Xa), (Xb), (Xc), or (Xd);
R 1′ , R 2′ , R 3′ and R 4′ are independently of each other H, D, F, Cl, a C 1 -C 25 alkyl group, a C 1 -C 25 alkoxy group, or a C 6 -C 10 aryloxy group; or
R 1 and R 2 together form a group of formula

R 1′ and R 2′ together form a group of formula

R 3 and R 4 together form a group of formula

R 3′ and R 4′ together form a group of formula

R 5 and R 6 together form a group of formula

and/or
R 8 and R 9 together form a group of formula

A 1 , A 2 , A 3 , A 4 , A 5 , A 6 , A 7 and A 8 are independently of each other H, D, F, Cl, a C 1 -C 25 alkyl group, or a donor group of formula (Xa), (Xb), (Xc), or (Xd);
A 9 , A 10 , A 11 , A 12 , A 13 , A 14 , A 15 and A 16 are independently of each other H, D, F, Cl, a C 1 -C 25 alkyl group, or a donor group of formula (Xa), (Xb), (Xc), or (Xd);
X 1 and X 2 are independently of each other a single bond, O, S, N(R 15 ), C(═O), C(R 16 )(R 17 ), B(R 18 ), or Si(R 19 )(R 20 ) and
R 10 , R 11 , R 12 , R 13 , R 21 and R 21′ are independently of each other H, D, F, Cl, or a C 1 -C 25 alkyl group;
R 14 , R 15 , R 16 , R 17 , R 18 , R 19 and R 20 are independently of each other H, D, a C 1 -C 25 alkyl group, or a C 6 -C 14 aryl group, which can optionally be substituted by one, or more groups selected from a C 1 -C 25 alkyl group, a C 1 -C 25 alkoxy group and a C 6 -C 10 aryloxy group;
with the proviso that at least one donor group of formula (Xc) is present in the compound of formula (I); characterized in that it emits delayed fluorescence.

2. The organic light-emitting element according to claim 1 , wherein
R 1 , R 2 , R 3 , R 4 , R 6 , R 7 , R 8 and R 9 are independently of each other H, a C 1 -C 25 alkyl group, a C 1 -C 25 alkoxy group, a C 6 -C 10 aryloxy group, a donor group of formula

or
R 1 and R 2 together form a group of formula

and/or
R 8 and R 9 together form a group of formula

R 5 is H, a C 1 -C 25 alkyl group, a group of formula

or a donor group of formula (Xa), (Xb), (Xc), or (Xd);
X 1 and X 2 are independently of each other a single bond, O, S, C(O), N(R 15 ), or C(R 16 )(R 17 ); and
R 10 , R 11 , R 12 , R 13 , R 21 and R 21′ are independently of each other H, or a C 1 -C 25 alkyl group;
R 14 and R 15 are independently of each other a group of formula

R 16 and R 17 are independently of each other H, a C 1 -C 25 alkyl group;
R 22 and R 23 are independently of each other H, a C 1 -C 25 alkyl group, a C 1 -C 25 alkoxy group, or a C 6 -C 10 aryloxy group;
with the proviso that at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 and R 9 is a donor group of formula (Xc).

3. The organic light-emitting element according to claim 1 , wherein the compound of formula (I) is a compound of formula

wherein
R 1 and R 2 are independently of each other H, or a C 1 -C 25 alkyl group, or
R 1 and R 2 together form a group of formula

R 3 , R 7 and R 8 are independently of each other H, a C 1 -C 25 alkyl group, or a donor group of formula

R 5 is H, a C 1 -C 25 alkyl group, a group of formula

or a donor group of formula (Xa), (Xb), (Xc), or (Xd);
R 9 is H, or
R 8 and R 9 together form a group of formula

X 1 and X 2 are independently of each other a single bond, O, S, N(R 15 ), or C(R 16 )(R 17 );
R 10 , R 11 , R 12 , R 13 , R 21 and R 21′ are independently of each other H, or a C 1 -C 25 alkyl group;
R 14 and R 15 are independently of each other a group of formula

R 16 and R 17 are independently of each other H, a C 1 -C 25 alkyl group;
R 22 and R 23 are independently of each other H, or a C 1 -C 25 alkyl group;
with the proviso that at least one of R 3 , R 5 and R 7 is a donor group of formula (Xc).

4. The organic light-emitting element according to claim 1 , wherein the compound of formula (I) is a compound of formula

wherein
R 1 and R 2 are independently of each other H, or a C 1 -C 25 alkyl group, or
R 1 and R 2 together form a group of formula

R 3 is H, a C 1 -C 25 alkyl group, or a donor group of formula

R 7 is H, a C 1 -C 25 alkyl group, or a donor group of formula (Xa), (Xb), (Xc), or (Xd);
R 8 and R 9 are H, or
R 8 and R 9 together form a group of formula

X 1 and X 2 are independently of each other a single bond, O, S, N(R 15 ), or C(R 16 )(R 17 );
R 10 , R 11 , R 12 , R 13 , R 21 and R 21′ are ind

Assignees

• Udc Ireland Ltd

Inventors

• Tanabe Junichi
• Lennartz Christian

Classifications

• H01L2251/552

  Electricity · mapped topic

• C09B21/00

  Thiazine dyes · CPC title

• H05K999/00

  Electricity · mapped topic

• C09K2211/1007

  Non-condensed systems · CPC title

• C09K2211/1059

  containing three nitrogen atoms as heteroatoms · CPC title