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EP-4739050-A1 - DISPLAY PANEL

EP4739050A1EP 4739050 A1EP4739050 A1EP 4739050A1EP-4739050-A1

Abstract

Embodiments of the present application provide a display panel, in which a hole control layer is disposed on a hole transport layer, a light-emitting material layer is disposed on the hole control layer, and the hole control layer includes a first sub-hole control layer and a second sub-hole control layer. An energy difference between a HOMO energy level of the first sub-hole control layer and a HOMO energy level of the second sub-hole control layer is greater than or equal to 0.2 eV, and the HOMO energy level of the second sub-hole control layer is greater than a HOMO energy level of the light-emitting material layer and less than a HOMO energy level of the hole transport layer.

Inventors

  • WANG, HAORAN

Assignees

  • Wuhan China Star Optoelectronics Semiconductor Display Technology Co., Ltd.

Dates

Publication Date
20260506
Application Date
20230718

Claims (13)

  1. A display panel, comprising: a first electrode; a hole transport layer disposed on the first electrode; a hole control layer disposed on the hole transport layer; a light-emitting material layer disposed on the hole control layer; and a second electrode disposed on the light-emitting material layer; wherein the hole control layer comprises a first sub-hole control layer and a second sub-hole control layer, a thickness of the first sub-hole control layer is less than a thickness of the second sub-hole control layer, and an energy difference between a HOMO energy level of the first sub-hole control layer and a HOMO energy level of the second sub-hole control layer is greater than or equal to 0.2 eV; and wherein the HOMO energy level of the second sub-hole control layer is greater than a HOMO energy level of the light-emitting material layer and less than a HOMO energy level of the hole transport layer.
  2. The display panel of claim 1, wherein a hole mobility of the first sub-hole control layer is less than a hole mobility of the second sub-hole control layer.
  3. The display panel of claim 2, wherein a ratio of the hole mobility of the first sub-hole control layer to the hole mobility of the second sub-hole control layer is less than or equal to 0.8.
  4. The display panel of claim 1, wherein the first sub-hole control layer is disposed between the hole transport layer and the second sub-hole control layer.
  5. The display panel of claim 4, wherein the HOMO energy level of the first sub-hole control layer is greater than the HOMO energy level of the light-emitting material layer and less than the HOMO energy level of the second sub-hole control layer; and wherein a LUMO energy level of the first sub-hole control layer is greater than a LUMO energy level of the light-emitting material layer, and less than both a LUMO energy level of the second sub-hole control layer and a LUMO energy level of the hole transport layer.
  6. The display panel of claim 4, wherein the HOMO energy level of the first sub-hole control layer is greater than the HOMO energy level of the hole transport layer; and wherein a LUMO energy level of the first sub-hole control layer is greater than all of a LUMO energy level of the light-emitting material layer, a LUMO energy level of the second sub-hole control layer, and a LUMO energy level of the hole transport layer.
  7. The display panel of claim 1, wherein the first sub-hole control layer is disposed between the second sub-hole control layer and the light-emitting material layer.
  8. The display panel of claim 7, wherein the HOMO energy level of the first sub-hole control layer is greater than the HOMO energy level of the second sub-hole control layer and less than the HOMO energy level of the hole transport layer; and wherein a LUMO energy level of the first sub-hole control layer is greater than a LUMO energy level of the light-emitting material layer and less than a LUMO energy level of the hole transport layer.
  9. The display panel of claim 7, wherein the HOMO energy level of the first sub-hole control layer is less than the HOMO energy level of the light-emitting material layer; and wherein a LUMO energy level of the first sub-hole control layer is greater than a LUMO energy level of the light-emitting material layer and less than a LUMO energy level of the hole transport layer.
  10. The display panel of claim 8, wherein the LUMO energy level of the first sub-hole control layer is equal to a LUMO energy level of the second sub-hole control layer.
  11. The display panel of claim 9, wherein the LUMO energy level of the first sub-hole control layer is equal to a LUMO energy level of the second sub-hole control layer.
  12. The display panel of claim 1, wherein the thickness of the first sub-hole control layer ranges from 3 nanometers to 10 nanometers.
  13. The display panel of claim 1, wherein a LUMO energy level of the second sub-hole control layer is greater than a LUMO energy level of the light-emitting material layer and less than a LUMO energy level of the hole transport layer; and wherein an energy difference between the LUMO energy level of the second sub-hole control layer and the LUMO energy level of the light-emitting material layer is greater than or equal to 0.2 eV.

Description

TECHNICAL FIELD The present application relates to the field of display technology, and in particular, to a display panel. BACKGROUND Organic light-emitting diode (OLED) display panels have been widely used in daily life, such as display screens for a mobile phone, a computer, a car, and the like. The organic light-emitting display panel includes multiple light-emitting devices that can emit light to display images. A red light-emitting device, a green light-emitting device, and a blue light-emitting device in the organic light-emitting display panel independently has the advantage of self-illumination, which can provide color images with high contrast ratio. However, if there is a significant difference in turn-on voltages (Vth) of the red light-emitting device, the green light-emitting device, and the blue light-emitting device, it will cause problems of light penetration or light leakage of the light-emitting device with a certain color under a black screen. For example, if the turn-on voltage of the green light-emitting device is greater than the turn-on voltage of the red light-emitting device, the red light-emitting device is also brightened when only the green light-emitting device wants to be lit. SUMMARY Embodiments of the present application provide a display panel that can address a problem of light penetration or light leakage of a light-emitting device with a certain color under a black screen. Embodiments of the present application provide a display panel, including: a first electrode;a hole transport layer disposed on the first electrode;a hole control layer disposed on the hole transport layer;a light-emitting material layer disposed on the hole control layer; anda second electrode disposed on the light-emitting material layer;in which the hole control layer includes a first sub-hole control layer and a second sub-hole control layer, a thickness of the first sub-hole control layer is less than a thickness of the second sub-hole control layer, and an energy difference between a HOMO energy level of the first sub-hole control layer and a HOMO energy level of the second sub-hole control layer is greater than or equal to 0.2 eV, andthe HOMO energy level of the second sub-hole control layer is greater than a HOMO energy level of the light-emitting material layer and less than a HOMO energy level of the hole transport layer. Optionally, in some embodiments, a hole mobility of the first sub-hole control layer may be less than a hole mobility of the second sub-hole control layer. Optionally, in some embodiments, a ratio of the hole mobility of the first sub-hole control layer to the hole mobility of the second sub-hole control layer may be less than or equal to 0.8. Optionally, in some embodiments, the first sub-hole control layer may be disposed between the hole transport layer and the second sub-hole control layer. Optionally, in some embodiments, the HOMO energy level of the first sub-hole control layer may be greater than the HOMO energy level of the light-emitting material layer and less than the HOMO energy level of the second sub-hole control layer; and a LUMO energy level of the first sub-hole control layer may be greater than a LUMO energy level of the light-emitting material layer, and less than a LUMO energy level of the second sub-hole control layer and a LUMO energy level of the hole transport layer. Optionally, in some embodiments, the HOMO energy level of the first sub-hole control layer may be greater than the HOMO energy level of the hole transport layer; and a LUMO energy level of the first sub-hole control layer may be greater than a LUMO energy level of the light-emitting material layer, a LUMO energy level of the second sub-hole control layer, and a LUMO energy level of the hole transport layer. Optionally, in some embodiments, the first sub-hole control layer may be disposed between the second sub-hole control layer and the light-emitting material layer. Optionally, in some embodiments, the HOMO energy level of the first sub-hole control layer may be greater than the HOMO energy level of the second sub-hole control layer and less than the HOMO energy level of the hole transport layer; and a LUMO energy level of the first sub-hole control layer may be greater than a LUMO energy level of the light-emitting material layer and less than a LUMO energy level of the hole transport layer. Optionally, in some embodiments, the HOMO energy level of the first sub-hole control layer may be less than the HOMO energy level of the light-emitting material layer; and a LUMO energy level of the first sub-hole control layer may be greater than a LUMO energy level of the light-emitting material layer and less than a LUMO energy level of the hole transport layer. Optionally, in some embodiments, the LUMO energy level of the first sub-hole control layer may be equal to a LUMO energy level of the second sub-hole control layer. Optionally, in some embodiments, the thickness of the first sub-hole contro