Light emitting device and display apparatus including the light emitting device

Patent metadata

Field	Value
Publication number	US-11211432-B2
Application number	US-202016812558-A
Country	US
Kind code	B2
Filing date	Mar 9, 2020
Priority date	Jun 19, 2019
Publication date	Dec 28, 2021
Grant date	Dec 28, 2021

Abstract

Provided a light emitting device including a first metal reflection layer including a phase modulation surface configured to magnetically resonate incident light, a color conversion layer provided on the phase modulation surface of the first metal reflection layer and including a photoluminescent material, a first electrode provided on the color conversion layer opposite to the first metal reflection layer, a white organic light emitting layer provided on the first electrode opposite to the color conversion layer, and a second electrode provided on the white organic light emitting layer opposite to the first electrode.

First claim

What is claimed is:

1. A light emitting device comprising:
a first metal reflection layer comprising a phase modulation surface configured to magnetically resonate light incident on the first metal reflection layer;
a color conversion layer provided on the phase modulation surface of the first metal reflection layer and comprising a photoluminescent material;
a first electrode provided on the color conversion layer opposite to the first metal reflection layer;
a white organic light emitting layer provided on the first electrode opposite to the color conversion layer; and
a second electrode provided on the white organic light emitting layer opposite to the first electrode,
wherein the white organic light emitting layer includes a red organic light-emitting layer, a green organic light-emitting layer, and a blue organic light emitting layer.

2. The light emitting device of claim 1 , wherein the first metal reflection layer and the second electrode form a microcavity having a resonance wavelength.

3. The light emitting device of claim 1 , wherein the phase modulation surface comprises a meta structure in which nanopatterns are periodically provided.

4. The light emitting device of claim 1 , wherein the color conversion layer further comprises a dielectric, the photoluminescent material being dispersed in the dielectric.

5. The light emitting device of claim 1 , wherein the photoluminescent material comprises a green photoluminescent material configured to convert blue light into green light or a red photoluminescent material configured to convert blue light and green light respectively into red light.

6. The light emitting device of claim 1 , wherein the color conversion layer covers the phase modulation surface of the first metal reflection layer.

7. The light emitting device of claim 1 , further comprising:
a transparent planarization layer provided between the first metal reflection layer and the color conversion layer and covering the phase modulation surface of the first metal reflection layer.

8. The light emitting device of claim 1 , wherein the first electrode comprises a transparent electrode, and the second electrode comprises a translucent electrode configured to transmit a portion of light incident on the second electrode and reflect a remaining portion of the light incident on the second electrode.

9. The light emitting device of claim 1 , wherein the first electrode comprises a transparent electrode and the second electrode comprises a reflective electrode, and
wherein the first metal reflection layer is a translucent layer configured to transmit a portion of the light incident on the first metal reflection layer and reflect a remaining portion of the light incident on the first metal reflection layer.

10. The light emitting device of claim 1 , further comprising:
a second metal reflection layer provided on the second electrode and comprising a phase modulation surface; and
a planarization layer provided between the second electrode and the second metal reflection layer and covering the phase modulation surface of the second metal reflection layer.

11. The light emitting device of claim 10 , wherein the first metal reflection layer and the second metal reflection layer form a microcavity having a resonance wavelength.

12. The light emitting device of claim 10 , wherein the first electrode and the second electrode respectively comprise a transparent electrode, and
wherein one of the first metal reflection layer and the second metal reflection layer is configured to reflect light, and the other of the first reflection layer and the second metal reflection layer is translucent and configured to transmit a portion of light and reflect a remaining portion of the light.

13. A display apparatus comprising:
a plurality of pixels configured to emit light having a plurality of colors,
wherein at least one of the plurality of pixels comprises:
a first metal reflection layer comprising a phase modulation surface configured to magnetically resonate light incident on the first metal reflection layer;
a color conversion layer provided on the phase modulation surface of the first metal reflection layer and comprising a photoluminescent material;
a first electrode provided on the color conversion layer opposite to the first metal reflection layer;
a white organic light emitting layer provided on the first electrode opposite to the color conversion layer; and
a second electrode provided on the white organic light emitting layer opposite to the first electrode,
wherein the white organic light emitting layer includes a red organic light-emitting layer, a green organic light-emitting layer, and a blue organic light emitting layer.

14. The display apparatus of claim 13 , wherein the phase modulation surface comprises a meta structure in which nanopatterns are periodically provided.

15. The display apparatus of claim 13 , wherein the color conversion layer further comprises a dielectric, the photoluminescent material being dispersed in the dielectric.

16. The display apparatus of claim 13 , wherein the color conversion layer covers the phase modulation surface of the first metal reflection layer.

17. The display apparatus of claim 13 , wherein the at least one of the plurality of pixels further comprises a transparent planarization layer provided between the first metal reflection layer and the color conversion layer and covering the phase modulation surface of the first metal reflection layer.

18. The display apparatus of claim 13 , wherein the at least one of the plurality of pixels further comprises:
a second metal reflection layer provided on the second electrode and comprising a phase modulation surface; and
a planarization layer provided between the second electrode and the second metal reflection layer and covering the phase modulation surface of the second metal reflection layer.

19. The display apparatus of claim 13 , wherein the plurality of pixels comprise a blue pixel, a green pixel, and a red pixel.

20. The display apparatus of claim 19 , wherein a photoluminescent material included in the green pixel comprises a green photoluminescent material configured to convert blue light into green light, and a photoluminescent material included in the red pixel comprises a red photoluminescent material configured to convert blue light and green light respectively into red light.

21. A light emitting device comprising:
a first electrode;
a second electrode;
a light emitting layer provided between the first electrode and the second electrode, and configured to emit white light;
a metal reflection layer provided on the first electrode opposite to the light emitting layer, the metal reflection layer comprising a phase modulation surface configured to resonate a specific wavelength of the white light emitted from the light emitting layer; and
a color conversion layer provided between the first electrode and the metal reflection layer, and configured to convert a portion of the white light into light having the specific wavelength,
wherein the light emitting layer includes a red organic light-emitting layer, a green organic light-emitting layer, and a blue organic light emitting layer.

22. The light emitting device of claim 21 , wherein the metal reflection layer comprises at least one of silver (Ag), aluminum (Al), and gold (Au).

23. The light emitting device of claim 21 , wherein the phase modulation surface comprises a meta structure

Assignees

• Samsung Electronics Co Ltd

Inventors

• Joo Wonjae
• Kyoung Jisoo
• Kwon Youngnam

Classifications

• H10K50/11

  characterised by the electroluminescent [EL] layers · CPC title

• H10K50/85 Primary

  Arrangements for extracting light from the devices · CPC title

• H10K59/876

  comprising a resonant cavity structure, e.g. Bragg reflector pair · CPC title

• H01L27/3218

  Electricity · mapped topic

• H01L27/322 Primary

  Electricity · mapped topic