Organic electroluminescence device

Abstract

An organic electroluminescence device including at least a light-emitting layer between a pair of electrodes and a hole transport layer between the light-emitting layer and an anode of the pair of electrodes, wherein the device further includes a mixture layer of an electron transporting material and a hole transporting material, the mixture layer being disposed between the light-emitting layer and the hole transport layer and in direct contact with the light-emitting layer. An organic electroluminescence device having high light emitting efficiency and high driving durability is provided.

Description

Claims

1. An organic electroluminescence device comprising at least a light-emitting layer between a pair of electrodes and a hole transport layer between the light-emitting layer and an anode of the pair of electrodes, wherein the device further comprises a mixture layer of an electron transporting material and a hole transporting material between the light-emitting layer and the hole transport layer, and the mixture layer is in direct contact with the light-emitting layer.

2. The organic electroluminescence device according to claim 1, wherein the electron transporting material contained in the mixture layer is a metal complex.

3. The organic electroluminescence device according to claim 2, wherein the metal complex is a compound represented by the following formula (1):

4. The organic electroluminescence device according to claim 1, wherein the electron transporting material contained in the mixture layer has an electron mobility of 10−5 cm2/V·s or more.

5. The organic electroluminescence device according to claim 1, wherein the electron transporting material contained in the mixture layer is a metal complex having an electron mobility of 10−5 cm2/V·s or more.

6. The organic electroluminescence device according to claim 1, wherein the electron transporting material contained in the mixture layer is a compound represented by the following formula (1) and has an electron mobility of 10−5 cm2/V·s or more:

7. The organic electroluminescence device according to claim 1, wherein the mixture layer has a thickness in a range from 0.1 nm to 20 nm.

8. The organic electroluminescence device according to claim 1, wherein an electron mobility in the mixture layer is higher than that in the hole transport layer.

9. The organic electroluminescence device according to claim 8, wherein the electron mobility in the mixture layer is at least ten times larger than that in the hole transport layer.

10. The organic electroluminescence device according to claim 1, wherein the light-emitting layer contains plural host materials.

11. The organic electroluminescence device according to claim 10, wherein the plural host materials include at least an electron transporting host material and a hole transporting host material.