Organic light emitting diode and display device having enhanced viewing angles

Patent metadata

Field	Value
Publication number	US-9692017-B2
Application number	US-201514698473-A
Country	US
Kind code	B2
Filing date	Apr 28, 2015
Priority date	May 14, 2014
Publication date	Jun 27, 2017
Grant date	Jun 27, 2017

Abstract

An organic light emitting diode can include a first electrode and a second electrode; an organic light emitting layer between the first electrode and the second electrode; and a auxiliary light emitting layer between the first electrode and the organic light emitting layer or between the organic light emitting layer and the second electrode, wherein a difference between a main peak wavelength of light emitted from the organic light emitting layer itself and a main peak wavelength of light out-coupling between the first and second electrodes is within a predetermined range.

First claim

What is claimed is:

1. An organic light emitting diode in each of red, green and blue sub pixels, comprising:
a first electrode and a second electrode;
an organic light emitting layer between the first electrode and the second electrode; and
an auxiliary light emitting layer between the first electrode and the organic light emitting layer or between the organic light emitting layer and the second electrode,
wherein a difference between a main peak wavelength of light emitted from the organic light emitting layer itself and a main peak wavelength of light out-coupling between the first and second electrodes is within a range of −14 nm to −2 nm,
wherein the main peak wavelength of light out-coupling between the first and second electrodes has a larger value than the main peak wavelength of light emitted from the organic light emitting layer itself in each of the green and blue sub pixels, and
wherein a value of a maximum peak at a curve of a color coordinate variation rate (Δu′v′) of the organic light emitting diode is equal to or less than 0.043 within a range of viewing angles of −80 degrees to +80 degrees.

2. The organic light emitting diode according to claim 1 , wherein the curve of the color coordinate variation rate (Δu′v′) of the organic light emitting diode has an M-like shape within the range of viewing angles of −80 degrees to +80 degrees.

3. The organic light emitting diode according to claim 1 , wherein the organic light emitting layer is a green organic light emitting layer, and the difference between the main peak wavelength of light emitted from the green organic light emitting layer itself and the main peak wavelength of light out-coupling between the first and second electrodes is within a range of −14 nm to −4 nm.

4. The organic light emitting diode according to claim 3 , wherein the main peak wavelength of light emitted from the green organic light emitting layer itself is within a range of 520 nm to 580 nm.

5. The organic light emitting diode according to claim 4 , wherein the value of the maximum peak at the curve of a color coordinate variation rate (Δu′v′) of the organic light emitting diode is equal to or less than 0.040 within the range of viewing angles of −80 degrees to +80 degrees.

6. The organic light emitting diode according to claim 5 , wherein the auxiliary light emitting layer is a hole transporting layer, and the hole transporting layer has a thickness within a range of 97 nm to 100 nm.

7. The organic light emitting diode according to claim 1 , wherein the organic light emitting layer is a blue organic light emitting layer, and the difference between the main peak wavelength of light emitted from the blue organic light emitting layer itself and the main peak wavelength of light out-coupling between the first and second electrodes is within a range of −4 nm to −2 nm.

8. The organic light emitting diode according to claim 7 , wherein the main peak wavelength of light emitted from the blue organic light emitting layer itself is within a range of 450 nm to 480 nm.

9. The organic light emitting diode according to claim 8 , wherein the auxiliary light emitting layer is a hole transporting layer, and the hole transporting layer has a thickness within a range of 99 nm to 100 nm.

10. A display device, comprising:
an organic light emitting diode including two electrodes and an organic light emitting layer therebetween in each of red, green and blue sub pixels,
wherein, to dispose a maximum peak at a curve of a color coordinate variation rate (Δu′v′) of the organic light emitting diode within a range of viewing angles of −80 degrees to +80 degrees, a thickness of the organic light emitting diode is optimized such that a main peak wavelength of light out-coupling between the two electrodes has a larger value than a main peak wavelength of light emitted from the organic light emitting layer itself in each of the green and blue sub pixels, and
wherein the curve of the color coordinate variation rate (Δu′v′) of the organic light emitting diode has an M-like shape within the range of viewing angles of −80 degrees to +80 degrees.

11. The display device according to claim 10 , wherein the main peak wavelength of light out-coupling between the two electrodes is determined on a basis of the main peak wavelength of light emitted from the organic light emitting layer itself such that the maximum peak at the curve of the color coordinate variation rate (Δu′v′) of the organic light emitting diode is disposed within the range of viewing angles of −80 degrees to +80 degrees.

12. The display device according to claim 10 , wherein a difference between the main peak wavelength of light emitted from the organic light emitting layer itself and the main peak wavelength of light out-coupling between the two electrodes is within a range of −14 nm to −2 nm.

13. The display device according to claim 12 , wherein the main peak wavelength of light emitted from the organic light emitting layer itself is within a range of 520 nm to 580 nm, and a value of the maximum peak at the curve of the color coordinate variation rate (Δu′v′) of the organic light emitting diode is equal to or less than 0.040 within the range of viewing angles of −80 degrees to +80 degrees.

14. The display device according to claim 12 , wherein the main peak wavelength of light emitted from the organic light emitting layer itself is within a range of 450 nm to 480 nm, and a value of the maximum peak at the curve of the color coordinate variation rate (Δu′v′) of the organic light emitting diode is equal to or less than 0.043 within the range of viewing angles of −80 degrees to +80 degrees.

Assignees

• Lg Display Co Ltd

Inventors

• Kim Ho-Sung
• Kim Mi-Na

Classifications

• H01L51/5068

  Electricity · mapped topic

• H01L2251/558

  Electricity · mapped topic

• H01L51/5206

  Electricity · mapped topic

• H01L51/5265

  Electricity · mapped topic

• H01L51/5221

  Electricity · mapped topic