Fluorescent organic light emitting elements having high efficiency

Patent metadata

Field	Value
Publication number	US-10586930-B2
Application number	US-201515312115-A
Country	US
Kind code	B2
Filing date	May 11, 2015
Priority date	May 19, 2014
Publication date	Mar 10, 2020
Grant date	Mar 10, 2020

Abstract

The present invention relates to organic light emitting elements, comprising thermally activated delayed fluorescence (TADF) emitters and/or hosts of formula

which have a sufficiently small energy gap between S 1 and T 1 (ΔE ST ) to enable up-conversion of the triplet exciton from T 1 to S 1 . The organic light emitting elements show high electroluminescent efficiency.

First claim

The invention claimed is:

1. A compound of formula I

wherein
X is O,
Y 1 , Y 2 , Y 3 and Y 4 are independently of each other a direct bond, or a group of formula -[A 1 ]-[A 2 ] y -, wherein
A 1 and A 2 are independently of each other —CH═CH—, —C≡C— or a C 6 -C 10 arylene group, which may optionally be substituted by one or more C 1 -C 25 alkyl groups; y is 0, or 1;
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

X 1 is O, S, N(R 15 ), C(R 16 )(R 17 ), B(R 18 ), or Si(R 19 )(R 20 ),
R 10 , R 11 , R 21 and R 21′ are independently of each other H, D, F, Cl, or a C 1 -C 25 alkyl group;
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 (Xa), or (Xd) is present in the compound of formula (I); and
with the proviso that when R 2 and R 4 are each a donor group of formula (Xa), at least one of Y 2 and Y 4 is not a C6-C 10 arylene.

2. A device comprising a compound according to claim 1 , wherein the device emits delayed fluorescence.

3. The compound according to claim 1 wherein Y 1 , Y 2 , Y 3 and Y 4 are independently of each other a direct bond, or a group of formula

4. The compound according to claim 1 , wherein
R 1 , R 2 , R 3 and R 4 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

X 1 is O, S, N(R 15 ), or C(R 16 )(R 17 ); and
R 15 is 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 and R 4 is a donor group of formula (Xa), or (Xd).

5. The compound according to claim 4 , wherein the donor group is a donor group of formula (Xa), wherein X 1 is O, S, C(CH 3 )(CH 3 ),

or a donor group of formula (Xd), wherein R 21 and R 21′ are H.

6. The compound according to claim 1 , wherein the donor group is a group of formula

7. The compound according to claim 1 , wherein the compound of formula (I) is a compound of formula (Ia)

wherein
Y 1 and Y 3 are a direct bond;
R 1 and R 3 are H;
Y 2 and Y 4 are a direct bond, or a group of formula

R 2 and R 4 are independently of each other a donor group of formula (Xa), or (Xd); and
with the proviso that when both Y 2 and Y 4 are

at least one of R 2 and R 4 is a donor group of formula (Xd);
or
a compound of formula (Ia), wherein
Y 2 and Y 4 are a direct bond;
R 2 and R 4 are H;
Y 1 and Y 3 are a direct bond, or a group of formula

R 1 and R 3 are independently of each other a donor group of formula (Xa), or (Xd);
or
a compound of formula (Ia) wherein
Y 4 is a direct bond, or a group of formula

R 4 is a donor group of formula (Xa), or (Xd);
Y 2 is a group of formula

R 2 is H;
Y 1 and Y 3 are a direct bond;
R 1 and R 3 are H;
or
a compound of formula (Ia) wherein
Y 1 is a direct bond, or a group of formula

R 1 is a donor group of formula (Xa), or (Xd);
Y 2 , Y 3 and Y 4 are a group of formula

R 2 , R 3 and R 4 are H, wherein

the donor group (Xa) is a group of formula

and
the donor group (Xd) is a group of formula

8. A light-emitting layer comprising the compound according to claim 1 .

9. An organic light emitting element, comprising the compound of formula (I) according to claim 1 .

10. The organic light-emitting element according to claim 9 , comprising a light-emitting layer, wherein the light-emitting layer comprises a host material and a guest material, wherein the guest material comprises the compound of formula (I).

11. The organic light-emitting element according to claim 9 , comprising a light-emitting layer, wherein the light-emitting layer comprises a host material and a guest material, wherein the host material comprises the compound of formula (I).

12. The organic light-emitting element according to claim 9 , wherein the organic light-emitting element emits delayed fluorescence.

13. A device selected from the group consisting of a electrophotographic photoreceptor, photoelectric converter, sensor, dye laser, solar cell device and organic light emitting element, wherein the device comprises a compound according to claim 1 .

Assignees

• Udc Ireland Ltd

Inventors

• Tanabe Junichi
• Lennartz Christian

Classifications

• C09B57/00

  Other synthetic dyes of known constitution · CPC title

• C09K11/06

  containing organic luminescent materials · CPC title

• C07D513/04

  Ortho-condensed systems · CPC title

• Y02E10/549

  Organic PV cells · CPC title

• C07D498/04 Primary

  Ortho-condensed systems · CPC title