Organic electroluminescence device

Abstract

An organic electroluminescence device having, between a pair of electrodes, at least a light-emitting layer, a first hole transport layer between the light-emitting layer and an anode, and a first electron transport layer between the light-emitting layer and a cathode, wherein the organic electroluminescence device has at least one of a second electron transport layer, which is disposed between the light-emitting layer and the first hole transport layer and adjacent to the light-emitting layer, or a second hole transport layer, which is disposed between the light-emitting layer and the first electron transport layer and adjacent to the light-emitting layer. An organic electroluminescence device having high emission efficiency and high driving durability is provided.

Description

Claims

1. An organic electroluminescence device having, between a pair of electrodes, at least a light-emitting layer, a first hole transport layer between the light-emitting layer and an anode, and a first electron transport layer between the light-emitting layer and a cathode, wherein the organic electroluminescence device has at least: one of a second electron transport layer which is disposed between the light-emitting layer and the first hole transport layer and adjacent to the light-emitting layer; of a second hole transport layer which is disposed between the light-emitting layer and the first electron transport layer and adjacent to the light-emitting layer.

2. An organic electroluminescence device according to claim 1, wherein the organic electroluminescence device has the second electron transport layer.

3. An organic electroluminescence device according to claim 1, wherein the organic electroluminescence device has the second hole transport layer.

4. An organic electroluminescence device according to claim 1, wherein the organic electroluminescence device has the second electron transport layer and the second hole transport layer.

5. An organic electroluminescence device according to claim 1, wherein the second electron transport layer contains a metal complex as an electron transporting material.

6. An organic electroluminescence device according to claim 5, wherein the electron transporting material has an electron mobility of 10−5 cm2/V·s or more.

7. An organic electroluminescence device according to claim 1, wherein a thickness of the second electron transport layer is 0.1 nm to 20 nm.

8. An organic electroluminescence device according to claim 1, wherein an electron mobility of the second electron transport layer is larger than an electron mobility of the first hole transport layer.

9. An organic electroluminescence device according to claim 8, wherein the electron mobility of the second electron transport layer is at least 10 times larger than the electron mobility of the first hole transport layer.

10. An organic electroluminescence device according to claim 5, wherein the metal complex is a compound represented by the following formula (1):

11. An organic electroluminescence device according to claim 1, wherein the second hole transport layer contains a hole transporting material having a hole mobility of 10−4 cm2 V·s or more.

12. An organic electroluminescence device according to claim 1, wherein a thickness of the second hole transport layer is 0.1 nm to 20 nm.

13. An organic electroluminescence device according to claim 1, wherein a hole mobility of the second hole transport layer is larger than a hole mobility of the first electron transport layer.

14. An organic electroluminescence device according to claim 13, wherein the hole mobility of the second hole transport layer is at least 100 times larger than the hole mobility of the first electron transport layer.

15. An organic electroluminescence device according to claim 1, wherein the light-emitting layer has a plurality of host materials.

16. An organic electroluminescence device according to claim 15, wherein the plurality of host materials include at least an electron transporting host material and a hole transporting host material.