Electroluminescent device, display panel and display apparatus

• US 10,862,063 B2
• Filed: 06/06/2019
• Issued: 12/08/2020
• Est. Priority Date: 08/31/2018
• Status: Active Grant

• Current Assignee: BOE Technology Group Co., Ltd.
• Original Assignee: BOE Technology Group Co., Ltd.
• Inventors: Quan, Wei
• Primary Examiner(s): Elahi, Towfiq
• Application Number:
  US16/434,070
• Publication Number:
  US 20200075881A1
• Time in Patent Office: 551 Days
• CPC Class Codes: H04N 9/31 Projection devices for colour picture display , e.g. using electronic spatial light modulators [ESLM]
• CPC Class Codes: H10K 2102/3026 Top emission
• CPC Class Codes: H10K 2102/351 Thickness
• CPC Class Codes: H10K 50/81 Anodes
• CPC Class Codes: H10K 50/82 Cathodes
• CPC Class Codes: H10K 50/828 Transparent cathodes, e.g. comprising thin metal layers
• CPC Class Codes: H10K 50/85 Arrangements for extracting light from the devices
• CPC Class Codes: H10K 50/852 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: H10K 59/32 Stacked devices having two or more layers, each emitting at different wavelengths
• CPC Class Codes: H10K 59/35 comprising red-green-blue [RGB] subpixels

Abstract

An electroluminescent device, a display panel and a display apparatus are disclosed. The electroluminescent device includes: a substrate; an anode on the substrate; a luminescent layer on a side of the anode facing away from the substrate; and a cathode on a side of the luminescent layer facing away from the substrate. The cathode includes a transflective layer on the side of the luminescent layer facing away from the substrate; and a light-emission enhancement layer on a side of the transflective layer facing away from the substrate. The anode is configured to reflect light incident thereon, a material of the transflective layer includes metal, and the transflective layer is configured to transmit a first portion of light incident thereon and to reflect a second portion of the light incident thereon.

Claims

1. An electroluminescent device comprising:

a substrate;

an anode on the substrate;

a luminescent layer on a side of the anode facing away from the substrate; and

a cathode on a side of the luminescent layer facing away from the substrate, the cathode comprising;

a transflective layer on the side of the luminescent layer facing away from the substrate; and

a light-emission enhancement layer on a side of the transflective layer facing away from the substrate,

wherein the anode is configured to reflect light incident thereon, a material of the transflective layer comprises metal, and the transflective layer is configured to transmit a first portion of light incident thereon and to reflect a second portion of the light incident thereon, and

wherein the cathode further comprises an electrode layer between the transflective layer and the light-emission enhancement layer,

wherein a thickness of the electrode layer is determined according to a design resistance value of the cathode, a thickness of the transflective layer, and a thickness of the light-emission enhancement layer.

2. The electroluminescent device according to claim 1, wherein the material of the transflective layer comprises a magnesium-silver alloy.

3. The electroluminescent device according to claim 1, wherein a thickness of the light-emission enhancement layer is related to a material of the luminescent layer.

4. The electroluminescent device according to claim 3, wherein:

the luminescent layer is a luminescent layer that emits red light, and the thickness of the light-emission enhancement layer is in a range of 110 nm to 120 nm;

or

the luminescent layer is a luminescent layer that emits green light, and the thickness of the light-emission enhancement layer is in a range of 90 nm to 100 nm;

or

the luminescent layer is a luminescent layer that emits blue light, and the thickness of the light-emission enhancement layer is in a range of 80 nm to 90 nm.

5. The electroluminescent device according to claim 1, wherein a material of the light-emission enhancement layer comprises a transparent oxide.

6. The electroluminescent device according to claim 1, wherein the transflective layer has a thickness greater than 8 nm.

7. The electroluminescent device according to claim 1, wherein an orthographic projection of each of the anode, the transflective layer and the light-emission enhancement layer on the substrate covers an orthographic projection of the luminescent layer on the substrate.

8. The electroluminescent device according to claim 1, wherein the electrode layer comprises the same material as the light-emission enhancement layer.

9. The electroluminescent device according to claim 8, wherein a material of the electrode layer comprises a transparent oxide.

10. The electroluminescent device according to claim 1, wherein the anode comprises:

a conductive anode layer on the substrate; and

a reflective layer between the conductive anode layer and the substrate.

11. The electroluminescent device according to claim 10, wherein a material of the reflective layer comprises silver.

12. The electroluminescent device according to claim 1, wherein the luminescent layer comprises an organic electroluminescent material.

13. A display panel comprising the electroluminescent device according to claim 1.

14. A display apparatus comprising the display panel according to claim 13.