Light-emitting element, light-emitting device, authentication device, and electronic apparatus

Patent metadata

Field	Value
Publication number	US-2016359117-A1
Application number	US-201615157672-A
Country	US
Kind code	A1
Filing date	May 18, 2016
Priority date	Jun 3, 2015
Publication date	Dec 8, 2016
Grant date	—

Abstract

A light-emitting element includes an anode, a cathode, a light-emitting layer which is provided between the anode and the cathode and emits light in a wavelength range of 700 nm or more by conducting electricity between the anode and the cathode, and an electron transport layer which is provided between the light-emitting layer and the cathode, and includes a first electron transport layer located on the cathode side and a second electron transport layer located on the light-emitting layer side, wherein organic materials contained in the light-emitting layer, a hole injection layer, the first electron transport layer, and the second electron transport layer have a glass transition temperature Tg of 135° C. or higher or do not have a glass transition temperature.

First claim

What is claimed is:

1 . A light-emitting element, comprising:
an anode; a cathode; a light-emitting layer which is provided between the anode and the cathode and emits light in a wavelength range of 700 nm or more by conducting electricity between the anode and the cathode; a hole injection layer which is provided between the light-emitting layer and the anode; and an electron transport layer which is provided between the light-emitting layer and the cathode, and includes a first electron transport layer located on the cathode side and a second electron transport layer located on the light-emitting layer side, wherein organic materials contained in the light-emitting layer, the hole injection layer, the first electron transport layer, and the second electron transport layer have a glass transition temperature Tg of 135° C. or higher or do not have a glass transition temperature.

2 . The light-emitting element according to claim 1 , wherein the second electron transport layer contains a second anthracene-based compound as the organic material, and the second anthracene-based compound is an anthracene-based compound which has an anthracene skeleton but does not have a heterocyclic skeleton.

3 . The light-emitting element according to claim 2 , wherein the anthracene-based compound is a compound represented by the following general formula ETL2-A:

wherein R 1 and R 2 are each a hydrogen atom, an alkyl group, an aryl group which may have a substituent, or an arylamino group which may have a substituent, and R 1 and R 2 may be the same as or different from each other.

4 . The light-emitting element according to claim 2 , wherein the second anthracene-based compound has a glass transition temperature Tg of 145° C. or higher or does not have a glass transition temperature.

5 . The light-emitting element according to claim 1 , wherein
the light-emitting layer contains a host material as the organic material, the hole injection layer contains a hole-injecting material as the organic material, and the second electron transport layer contains a second anthracene-based compound as the organic material, and when the glass transition temperatures Tg of the host material, the hole-injecting material, and the second anthracene-based compound are represented by Tg(Host), Tg(HIL), and Tg(ETL2), respectively, Tg(Host), Tg(HIL), and Tg(ETL2) satisfy the following relational formula (I):
Tg(HIL)>Tg(Host) and Tg(ETL2)>Tg(Host)  (I).

6 . The light-emitting element according to claim 5 , wherein further Tg(HIL) and Tg(ETL2) satisfy the following relational formula (II):
Tg(HIL)>Tg(ETL2)  (II).

7 . The light-emitting element according to claim 1 , wherein the light-emitting element is used by conducting electricity between the anode and the cathode at a current density of 0.5 A/cm 2 or more and 2.0 A/cm 2 or less.

8 . A light-emitting device, comprising the light-emitting element according to claim 1 .

9 . A light-emitting device, comprising the light-emitting element according to claim 2 .

10 . A light-emitting device, comprising the light-emitting element according to claim 3 .

11 . A light-emitting device, comprising the light-emitting element according to claim 4 .

12 . A light-emitting device, comprising the light-emitting element according to claim 5 .

13 . An authentication device, comprising the light-emitting element according to claim 1 .

14 . An authentication device, comprising the light-emitting element according to claim 2 .

15 . An authentication device, comprising the light-emitting element according to claim 3 .

16 . An authentication device, comprising the light-emitting element according to claim 4 .

17 . An electronic apparatus, comprising the light-emitting element according to claim 1 .

18 . An electronic apparatus, comprising the light-emitting element according to claim 2 .

19 . An electronic apparatus, comprising the light-emitting element according to claim 3 .

20 . An electronic apparatus, comprising the light-emitting element according to claim 4 .

Assignees

• Seiko Epson Corp

Inventors

• Hamade Yuiga
• Fujita Tetsuji

Classifications

• C09K11/06

  containing organic luminescent materials · CPC title

• H05B33/20

  characterised by the chemical or physical composition or the arrangement of the material in which the electroluminescent material is embedded · CPC title

• C09K2211/1014

  bridged by heteroatoms, e.g. N, P, Si or B · CPC title

• C09K2211/1007

  Non-condensed systems · CPC title

• C09K11/025

  non-luminescent particle coatings or suspension media · CPC title