IP Library Granted Patent US 11,398,532
Granted Patent B2
US 11,398,532 · App. 17/040,929 · Granted Jul 26, 2022

Light-emitting device, light wavelength conversion device, and display device

Inventors: Kenichi Yoshimura (Sakai, JP); Tadashi Kobashi (Sakai, JP); Masashi Kago (Sakai, JP); Tatsuya Ryohwa (Sakai, JP); Makoto Izumi (Sakai, JP)
Assignee: SHARP KABUSHIKI KAISHA
H01L27/322G02F1/133514H01L27/3211H01L51/502H01L51/52G02F1/133617H01L51/0097H01L51/5056H01L51/5072H01L51/5088H01L51/5092H01L51/5206H01L51/5253H01L2227/326H01L2251/5338
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Quick Facts
Patent No.
US 11,398,532
App. No.
17/040,929
Granted
Jul 26, 2022
Kind
B2
Abstract

A light-emitting device includes: an anode electrode; a cathode electrode; a plurality of light-emitting layers sandwiched between the anode electrode and the cathode electrode; and a light absorption layer disposed between the plurality of light-emitting layers and a light extraction surface, wherein the plurality of light-emitting layers include InP based quantum dots and are configured to emit at least green color of light and red color of light, and the light absorption layer selectively absorbs light at 570 to 610 nm.

Claims (45)

1. A light-emitting device comprising:

an anode electrode;

a cathode electrode;

a plurality of light-emitting layers sandwiched between the anode electrode and the cathode electrode;

a light absorption layer disposed between the plurality of light-emitting layers and a light extraction surface; and

a substrate provided between the plurality of light-emitting layers and the light absorption layer,

wherein the plurality of light-emitting layers include InP based quantum dots and are configured to emit at least green color of light and red color of light,

the light absorption layer selectively absorbs light at 570 to 610 nm, and

the light absorption layer is provided in a region other than the region upper the region where the substrate deposits a blue light-emitting layer.

2. The light-emitting device according to claim 1 ,

wherein a peak wavelength in a light emission spectrum of the green color is 520 nm to 550 nm,

a peak wavelength in a light emission spectrum of the red color is 620 nm to 650 nm, and

each of half widths of the light emission spectrums of the green color and the red color is less than 50 nm.

3. The light-emitting device according to claim 1 ,

wherein a value obtained by dividing a light emission intensity of the green color at a wavelength of a sum of a value of a peak wavelength and a value of a half width of a light emission spectrum of the green color by a peak intensity of the light emission spectrum of the green color is less than 0.02, and

a value obtained by dividing a light emission intensity of the red color at a wavelength obtained by subtracting a value of a half width from a value of a peak wavelength of a light emission spectrum of the red color by a peak intensity of the light emission spectrum of the red color is less than 0.08.

4. The light-emitting device according to claim 1 ,

wherein a value obtained by dividing a light emission intensity of a light emission spectrum of the green color at a wavelength of 590 nm by a peak intensity of the light emission spectrum of the green color is less than 0.03, and

a value obtained by dividing a light emission intensity of a light emission spectrum of the red color at a wavelength of 590 nm by a peak intensity of the light emission spectrum of the red color is less than 0.05.

5. The light-emitting device according to claim 1 ,

wherein the light absorption layer comprises materials including a metal nanoplate.

6. The light-emitting device according to claim 1 , further comprising:

a hole transport layer deposited between the anode electrode and the plurality of light-emitting layers,

wherein the hole transport layer also serves as the light absorption layer due to the hole transport layer including a light absorbing material included in the light ab sorption layer.

7. The light-emitting device according to claim 1 , further comprising:

a hole injection layer deposited between the anode electrode and the plurality of light-emitting layers,

wherein the hole injection layer also serves as the light absorption layer due to the hole injection layer including a light absorbing material included in the light ab sorption layer.

8. The light-emitting device according to claim 1 ,

wherein the light-emitting device is a bottom-emitting type light-emitting device provided on a TFT layer provided with a resin layer on a top portion of the TFT layer, and

the resin layer also serves as the light absorption layer due to the resin layer including a light absorbing material included in the light absorption layer.

9. The light-emitting device according to claim 1 ,

wherein the light-emitting device is a top-emitting type light-emitting device provided below a sealing layer provided with an organic layer, and

the organic layer also serves as the light absorption layer due to the organic layer including a light absorbing material included in the light absorption layer.

10. A light wavelength conversion device comprising:

a plurality of wavelength conversion layers for wavelength conversion of light having a wavelength of white color; and

a light absorption layer disposed between the plurality of wavelength conversion layers and a light extraction surface,

wherein the plurality of wavelength conversion layers include InP based quantum dots, and are configured to wavelength convert light having the wavelength of the white color to at least green color and red color,

the light absorption layer selectively absorbs light at 570 to 610 nm, and

the light absorption layer is provided only for outputting light of the green color and the red color.

11. A display device comprising:

the light wavelength conversion device according to claim 10 ; and

a light-emitting apparatus configured to emit light incident on the light wavelength conversion device,

wherein the light-emitting apparatus includes a liquid crystal unit or an OLED panel for emitting light having a wavelength of white color.

12. The light wavelength conversion device according to claim 10 , further comprising:

a substrate provided between the plurality of wavelength conversion layers and the light absorption layer.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 23, 2020
From: YOSHIMURA, KENICHI; KOBASHI, TADASHI; KAGO, MASASHI; RYOHWA, TATSUYA; IZUMI, MAKOTO
To: SHARP KABUSHIKI KAISHA
Reel/Frame 053864/0614 →
Continuity (1)
Related Publication 20210020699A1 · Jan 21, 2021