Organic light emitting display device having layer to control charge transfer

Patent metadata

Field	Value
Publication number	US-12161003-B2
Application number	US-202318201621-A
Country	US
Kind code	B2
Filing date	May 24, 2023
Priority date	Nov 19, 2015
Publication date	Dec 3, 2024
Grant date	Dec 3, 2024

Abstract

Discussed is an organic light emitting display device including an anode, a first emission part on the anode, and including a first hole transfer layer, a first emission layer, and a first electron transfer layer, a second emission part on the first emission part, and including a second hole transfer layer, a second emission layer, and a second electron transfer layer, and a cathode on the second emission part. At least one among the first emission part and the second emission part can include an emission control layer having an absolute value of a HOMO energy level which is larger than an absolute value of a HOMO energy level of the first hole transfer layer or the second hole transfer layer. A hole mobility of the emission control layer is 1.0×10−1 cm2/Vs to 1.0×10−2 cm2/Vs lower than a hole mobility of the first hole transfer layer or the second hole transfer layer.

First claim

What is claimed is:

1. An organic light emitting display device, comprising:
an anode on a substrate;
a first emission part on the anode, the first emission part including a first hole transfer layer, a first emission layer on the first hole transfer layer, and a first electron transfer layer on the first emission layer;
a second emission part on the first emission part, the second emission part including a second hole transfer layer, a second emission layer on the second hole transfer layer, and a second electron transfer layer on the second emission layer;
an N-type charge generation layer between the first emission part and the second emission part; and
a cathode on the second emission part,
wherein at least one among the first emission part and the second emission part comprises an emission control layer having an absolute value of a highest occupied molecular orbital (HOMO) energy level which is larger than an absolute value of a HOMO energy level of the first hole transfer layer or the second hole transfer layer,
wherein a hole mobility of the emission control layer is 1.0×10 −1 cm 2 /Vs to 1.0×10 −2 cm 2 /Vs lower than a hole mobility of the first hole transfer layer or the second hole transfer layer,
wherein the hole mobility of the emission control layer is within a range of 1.0×10−5 cm 2 /Vs to 1.0×10 −6 cm 2 /Vs, and
wherein the first electron transfer layer comprises a material having a lowest unoccupied molecular orbital (LUMO) energy level which is 0.50 eV to 1.00 eV higher than a LUMO energy level of a host included in the N-type charge generation layer.

2. The organic light emitting display device of claim 1 , wherein an absolute value of a HOMO energy level of the emission control layer is 0.10 eV to 0.50 eV larger than an absolute value of a HOMO energy level of the first hole transfer layer or the second hole transfer layer.

3. The organic light emitting display device of claim 1 , wherein the second electron transfer layer comprises at least two materials, and a material having a small absolute value of a LUMO energy level among the at least two materials is higher in content than another material having a large absolute value of the LUMO energy level among the at least two materials.

4. The organic light emitting display device of claim 3 , wherein the first electron transfer layer comprises one among the at least two materials.

5. The organic light emitting display device of claim 1 , wherein the emission control layer is provided in the second emission part.

6. The organic light emitting display device of claim 5 , wherein the emission control layer is provided between the second hole transfer layer and the second emission layer.

7. The organic light emitting display device of claim 1 , wherein the first electron transfer layer and the second electron transfer layer each comprise at least two materials, and a material having a small absolute value of a LUMO energy level among the at least two materials is higher in amount than another material having a large absolute value of the LUMO energy level among the at least two materials.

8. The organic light emitting display device of claim 7 , wherein the large absolute value of the LUMO energy level of the material is included within a first range of 2.91 eV to 3.40 eV and the small absolute value of the LUMO energy level of the another material is included within a second range of 2.60 eV to 2.90 eV, and
wherein the first range and the second range do not overlap.

9. The organic light emitting display device of claim 1 , wherein the emission control layer is provided in the first emission part.

10. The organic light emitting display device of claim 9 , wherein the emission control layer is provided between the first hole transfer layer and the first emission layer.

11. The organic light emitting display device of claim 1 , wherein the emission control layer is provided in the first emission part.

12. The organic light emitting display device of claim 11 , wherein the emission control layer is between the first hole transfer layer and the first emission layer.

13. The organic light emitting display device of claim 1 , wherein the emission control layer is provided in the second emission part.

14. The organic light emitting display device of claim 13 , wherein the emission control layer is between the second hole transfer layer and the second emission layer.

15. The organic light emitting display device of claim 1 , wherein the first electron transfer layer is selected from the group consisting of anthracene derivatives, triazine derivatives, and carbazole derivatives.

16. The organic light emitting display device of claim 1 , wherein the first emission layer and the second emission layer emit light having the same color.

17. The organic light emitting display device of claim 1 , further comprising:
a thin film transistor on the substrate; and
a bank layer on the anode.

18. The organic light emitting display device of claim 1 , further comprising at least one pixel,
wherein each of the first emission layer and the second emission layer includes a red emission layer, a green emission layer, and a blue emission layer in the at least one pixel.

Assignees

• Lg Display Co Ltd

Inventors

• Park Eunjung

Classifications

• H10K2101/30

  Highest occupied molecular orbital [HOMO], lowest unoccupied molecular orbital [LUMO] or Fermi energy values · CPC title

• H10K2101/40

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

• H10K85/6572

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

• H10K85/654

  comprising only nitrogen as heteroatom (H10K85/652 takes precedence) · CPC title

• H10K85/615

  Polycyclic condensed aromatic hydrocarbons, e.g. anthracene · CPC title