ORGANIC ELECTROLUMINESCENT ELEMENT, LIGHTING DEVICE AND DISPLAY DEVICE

• US 20140197399A1
• Filed: 08/21/2012
• Published: 07/17/2014
• Est. Priority Date: 08/23/2011
• Status: Abandoned Application

• Current Assignee: Konica Minolta Inc.
• Original Assignee: Konica Minolta Inc.
• Inventors: Taka, Hideo
• Application Number:
  US14/238,886
• Publication Number:
  US 20140197399A1
• Time in Patent Office: Days
• US Class Current: 257/40
• CPC Class Codes: H05B 33/10 Apparatus or processes specially adapted to the manufacture of electroluminescent light sources
• CPC Class Codes: H10K 2101/10 Triplet emission
• CPC Class Codes: H10K 2101/40 Interrelation of parameters between multiple constituent active layers or sublayers, e.g. HOMO values in adjacent layers
• CPC Class Codes: H10K 2102/361 Temperature
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/15 Hole transporting layers
• CPC Class Codes: H10K 50/16 Electron transporting layers
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays

Abstract

Provided are: an organic electroluminescent element that has high charge injection/transport performance and a long service life, with little change in driving voltage over time; a manufacturing method; a lighting device; and a display device. An organic EL element according to the present invention comprises a plurality of organic compound layers that include a hole transport layer, a light emitting layer, and an electron transport layer. This organic EL element is characterized in that (1) the hole transport layer and the electron transport layer are each adjacent to the light emitting layer, and the light emitting layer contains a phosphorescent light-emitting organic metal complex compound; (2) the Tg of a hole transport material having the highest constituent ratio among the constituents of the hole transport layer is higher that the Tg of a host material having the highest constituent ration among the constituents of the light emitting layer; and (3) the Tg of an electron transport material having the highest constituents ratio among the constituents of the electron transport layer is higher than the Tg of the host material having the highest constituent ration among the constituents of the light emitting layer.

Claims

1. An organic electroluminescent element comprising a plurality of organic compound layers including a hole-transporting layer, a light-emitting layer and an electron-transporting layer, the plurality of the organic compound layers being provided between an anode and a cathode, wherein

(1) the hole-transporting layer and the electron-transporting layer are each adjacent to the light-emitting layer,

(2) Tg(HT)>

Tg(EM) where a glass transition temperature (Tg) of a hole-transporting material constituting the hole-transporting layer in a highest constitution ratio among a hole-transporting material(s) constituting the hole-transporting layer is defined as Tg(HT) and a glass transition temperature (Tg) of a host material constituting the light-emitting layer in a highest constitution ratio among a host material(s) constituting the light-emitting layer is defined as Tg(EM),

(3) Tg(ET)>

Tg(EM) where a glass transition temperature (Tg) of an electron-transporting material constituting the electron-transporting layer in a highest constitution ratio among an electron-transporting material(s) constituting the electron-transporting layer is defined as Tg(HT) and the glass transition temperature (Tg) of the host material constituting the light-emitting layer in the highest constitution ratio among the host material(s) constituting the light-emitting layer is defined as Tg(EM), and

(4) a phosphorescent organic metal complex compound is contained as a material constituting the light-emitting layer.

2. The organic electroluminescent element of claim 1, wherein

the glass transition temperature Tg of the host material contained in the light-emitting layer ranges from 70 to 130°

C.

3. The organic electroluminescent element of claim 1, wherein

the hole-transporting material contained in the hole-transporting layer is a polymer.

4. The organic electroluminescent element of claim 1, wherein

the electron-transporting material contained in the electron-transporting layer is a polymer.

5. The organic electroluminescent element of claim 1, wherein

both of the hole-transporting material contained in the hole-transporting layer and the electron-transporting material contained in the electron-transporting layer are polymers.

6. The organic electroluminescent element of claim 1, wherein

at least one of the phosphorescent organic metal complex compound(s) is a compound represented by a following formula (1):

7. The organic electroluminescent element of claim 1, wherein

the organic electroluminescent element emits white light.

8. A lighting device comprising the organic electroluminescent element of claim 1.

9. A display device comprising the organic electroluminescent element of claim 1.