Organic light emitting display device having layer to control charge transfer

Patent metadata

Field	Value
Publication number	US-11700735-B2
Application number	US-202117200547-A
Country	US
Kind code	B2
Filing date	Mar 12, 2021
Priority date	Nov 19, 2015
Publication date	Jul 11, 2023
Grant date	Jul 11, 2023

Abstract

An organic light emitting display device is discussed, which includes an anode on a substrate, a first hole transfer layer on the anode, a first emission layer on the first hole transfer layer, a first electron transfer layer on the first emission layer, an N-type charge generation layer on the first electron transfer layer, a second hole transfer layer on the N-type charge generation layer, a first emission control layer on the second hole transfer layer, an absolute value of a highest occupied molecular orbital (HOMO) energy level of the first emission control layer being greater than an absolute value of a HOMO energy level of the second hole transfer layer, a second emission layer on the first emission control layer, a second electron transfer layer on the second emission layer and a cathode on the second electron transfer layer.

First claim

What is claimed is:

1. An organic light emitting display device, comprising:
an anode on a substrate;
a first hole transfer layer on the anode;
a first emission layer on the first hole transfer layer;
a first electron transfer layer on the first emission layer;
an N-type charge generation layer on the first electron transfer layer;
a second hole transfer layer on the N-type charge generation layer;
a first emission control layer on the second hole transfer layer, an absolute value of a highest occupied molecular orbital (HOMO) energy level of the first emission control layer being greater than an absolute value of a HOMO energy level of the second hole transfer layer;
a second emission layer on the first emission control layer;
a second electron transfer layer on the second emission layer; and
a cathode on the second electron transfer layer,
wherein a hole mobility of the first emission control layer is 1.0×10 −1 to 1.0×10 −2 times lower than a hole mobility of the second hole transfer layer.

2. The organic light emitting display device of claim 1 , wherein a difference between a lowest unoccupied molecular orbital (LUMO) energy level of the first electron transfer layer and a LUMO energy level of the N-type charge generation layer is 0.50 eV to 1.00 eV.

3. The organic light emitting display device of claim 1 , wherein an absolute value of a lowest unoccupied molecular orbital (LUMO) energy level of the first electron transfer layer is within a range of 2.00 eV to 2.50 eV, and an absolute value of a LIMO energy level of the N-type charge generation layer is within a range of 2.90 eV to 3.20 eV.

4. The organic light emitting display device of claim 1 , wherein the absolute value of the HOMO energy level of the first emission control layer is 0.1.0 eV to 0.50 eV greater than the absolute value of the HOMO energy level of the second hole transfer layer.

5. The organic light emitting display device of claim 1 , wherein the second electron transfer layer includes a first material and a second material and an absolute value of a LUMO energy level of the first material is different from an absolute value of a lowest unoccupied molecular orbital (LUMO) energy level of the second material.

6. The organic light emitting display device of claim 5 , wherein the absolute value of the LIMO energy level of the first material is within a range of 2.91 eV to 3.40 eV and the absolute value of the LUMO energy level of the second material is within a range of 2.60 eV to 2.90 eV.

7. The organic light emitting display device of claim 5 , wherein an amount of the second material is higher than an amount of the first material.

8. The organic light emitting display device of claim 5 , wherein a content of the second material is more than 50 wt % of a sum of the first material and the second material.

9. The organic light emitting display device of claim 5 , wherein the first material is selected from the group consisting of anthracene derivatives, triazine derivatives, and carbazole derivatives.

10. The organic light emitting display device of claim 1 , wherein the first hole transfer layer includes a P-type hole transfer layer doped with a P-type dopant.

11. The organic light emitting display device of claim 1 , wherein the first emission layer and the second emission layer include one or more of a red emitting layer, a green emitting layer, and a blue emitting layer.

12. The organic light emitting display device of claim 1 , wherein the first emission layer and the second emission layer are capable of emitting light having a same color.

13. The organic light emitting display device of claim 1 , further comprising a plurality of pixels having a red subpixel, a green subpixel, and a blue subpixel,
wherein the first emission layer and the second emission layer include a red emitting layer, a green emitting layer, and a blue emitting layer in each of the plurality of pixels.

14. The organic light emitting display device of claim 1 , further comprising a P-type charge generation layer between the N-type charge generation layer and the second hole transfer layer.

15. The organic light emitting display device of claim 1 , further comprising a second emission control layer between the first hole transfer layer and the first emission layer and a hole mobility of the second emission control layer is lower than a hole mobility of the first hole transfer layer.

16. The organic light emitting display device of claim 15 , wherein an absolute value of a HOMO energy level of the second emission control layer is greater than an absolute value of a HOMO energy level of the first hole transfer layer.

17. The organic light emitting display device of claim 1 , wherein the first electron transfer layer includes a first material and a second material and an absolute value of a lowest unoccupied molecular orbital (LUMO) energy level of the first material is different from an absolute value of a LUMO energy level of the second material.

18. The organic light emitting display device of claim 17 , wherein the absolute value of the LAM energy level of the first material is within a range of 2.91 eV to 3.40 eV and the absolute value of the LUMO energy level of the second material is within a range of 2.60 eV to 2.90 eV.

19. The organic light emitting display device of claim 17 , wherein an amount of the second material is higher than an amount of the first material.

20. The organic light emitting display device of claim 17 , wherein a content of the second material is more than 50 wt % of a sum of the first material and the second material.

21. The organic light emitting display device of claim 17 , wherein the first material is selected from the group consisting of anthracene derivatives, triazine derivatives, and carbazole derivatives.

22. An organic light emitting display device, comprising:
an anode on a substrate;
a first hole transfer layer on the anode;
a first emission control layer on the first hole transfer layer, an absolute value of a highest occupied molecular orbital (HOMO) energy level of the first emission control layer being greater than an absolute value of a HOMO energy level of the first hole transfer layer;
a first emission layer on the first emission control layer;
a first electron transfer layer on the first emission layer;
an N-type charge generation layer on the first electron transfer layer;
a second hole transfer layer on the N-type charge generation layer;
a second emission layer on the second hole transfer layer;
a second electron transfer layer on the second emission layer; and
a cathode on the second electron transfer layer,
wherein a hole mobility of the first emission control layer is 1.0×10 −1 to 1.0×10 −2 times lower than a hole mobility of the first hole transfer layer.

23. The organic light emitting display device of claim 22 , wherein a difference between a lowest unoccupied molecular orbital (LUMO) energy level of the first electron transfer layer and a LIMO energy level of the N-type charge generation layer is 0.50 eV to 1.00 eV.

24. The organic light emitting display device of claim 22 , wherein an absolute value of a lowest unoccupied molecular orbital (LUMO) energy level of the first electron transfer layer is within a range of 2.00 eV to 2.50 eV, and an absolute value of a LUMO energy level of the N-type charge generation layer is within a range of 2.90 eV to 3.20 eV.

25. The organic light emitting

Assignees

• Lg Display Co Ltd

Inventors

• Park Eunjung

Classifications

• H10K85/6572

  comprising only nitrogen in the heteroaromatic polycondensed ring system, e.g. phenanthroline or carbazole · CPC title

• H10K2101/40

  Interrelation of parameters between multiple constituent active layers or sublayers, e.g. HOMO values in adjacent layers · CPC title

• H10K85/324

  comprising aluminium, e.g. Alq3 · CPC title

• H10K59/32

  Stacked devices having two or more layers, each emitting at different wavelengths · CPC title

• H10K50/131

  with spacer layers between the electroluminescent layers · CPC title