Light emitting device

Patent metadata

Field	Value
Publication number	US-2016233425-A1
Application number	US-201415023734-A
Country	US
Kind code	A1
Filing date	Sep 19, 2014
Priority date	Oct 1, 2013
Publication date	Aug 11, 2016
Grant date	—

Abstract

A light emitting device includes an anode, a cathode, a light emitting layer disposed between the anode and the cathode, and an encapsulating layer. The temperature TA (° C.) at which an annealing treatment is conducted after the formation of the encapsulating layer and the glass transition temperature TG (° C.) of the material having the lowest glass transition temperature out of all materials each contained in an amount of 1 wt % or more in the light emitting layer satisfy the following formula (1): TA<TG (1). The current density IA at a voltage of 5 V applied before the annealing treatment and the current density IB at a voltage of 5 V applied after the annealing treatment satisfy the following formula (2):
0.50× IA≦IB ≦0.95× IA   (2).

First claim

1 . A light emitting device comprising
an anode, a cathode, a light emitting layer disposed between the anode and the cathode and an encapsulating layer, wherein the temperature TA (° C.) at which an annealing treatment is conducted after the formation of the encapsulating layer and the glass transition temperature TG (° C.) of the material having the lowest glass transition temperature out of all materials each contained in an amount of 1 wt % or more in the light emitting layer satisfy the following formula (1), and the current density IA at a voltage of 5 V applied before the annealing treatment and the current density IB at a voltage of 5 V applied after the annealing treatment satisfy the following formula (2):
TA<TG   (1)

0.50× IA≦IB≦ 0.95× IA   (2).

2 . The light emitting device according to claim 1 , wherein the TA and the TG satisfy the following formula (3):
TA<TG− 30  (3).

3 . The light emitting device according to claim 1 , wherein the TA is 50° C. or higher.

4 . The light emitting device according to claim 3 , wherein the TA is 50° C. to 80° C.

5 . The light emitting device according to claim 1 , wherein the IA and the IB satisfy the following formula (4):
0.70× IA≦IB≦ 0.90× IA   (4).

6 . The light emitting device according to claim 1 , wherein the light emitting layer comprises a polymer compound comprising a constitutional unit represented by the following formula (Y):
Ar Y1   (Y)
wherein Ar Y1 represents an arylene group, a divalent heterocyclic group or a divalent group in which at least one arylene group and at least one divalent heterocyclic group are bonded directly to each other, and these groups each optionally have a substituent.

7 . The light emitting device according to claim 6 , wherein the light emitting layer further comprises a triplet light emission complex.

Assignees

• Sumitomo Chemical Co

Inventors

• Asada Kohei
• Tanaka Shin-Ya
• Hayashi Naoki

Classifications

• C08G2261/135

  Cross-linked structures · CPC title

• C08G2261/3162

  Arylamines · CPC title

• C08G2261/148

  Side-chains having aromatic units · CPC title

• C08G2261/95

  Use in organic luminescent diodes · CPC title

• C08G2261/12

  Copolymers · CPC title