Search

CN-122003024-A - Light emitting device, display panel and electronic apparatus

CN122003024ACN 122003024 ACN122003024 ACN 122003024ACN-122003024-A

Abstract

The application relates to the technical field of display, and provides a light emitting device, a display panel and electronic equipment. The light-emitting device comprises an anode, a first light-emitting layer, a first electron transport layer, a second electron transport layer and a cathode, wherein the anode, the first light-emitting layer, the first electron transport layer and the second electron transport layer are arranged in a stacked mode, the first light-emitting layer is arranged between the first electron transport layer and the anode, the second electron transport layer is arranged between the cathode and the second electron transport layer, the refractive index of the first electron transport layer is larger than or equal to 1.8, and the refractive index of the second electron transport layer is smaller than or equal to 1.6. The double-layer electron transport structure improves the electron migration capability through the first electron transport layer, reduces the SPP loss through the second electron transport layer, and can improve the optical characteristics of the light-emitting device and the electrical characteristics of the light-emitting device.

Inventors

  • LI BINBIN
  • HU YUNSONG
  • QIN ZHIYUAN
  • LUO XINTAO

Assignees

  • 华为技术有限公司

Dates

Publication Date
20260508
Application Date
20241107

Claims (13)

  1. 1. The light-emitting device is characterized by comprising an anode, a first light-emitting layer, a first electron transport layer, a second electron transport layer and a cathode which are arranged in a stacked mode, wherein the first light-emitting layer, the first electron transport layer and the second electron transport layer are all arranged between the anode and the cathode, the first light-emitting layer is arranged between the first electron transport layer and the anode, the second electron transport layer is arranged between the cathode and the second electron transport layer, the refractive index of the first electron transport layer is larger than or equal to 1.8, and the refractive index of the second electron transport layer is smaller than or equal to 1.6.
  2. 2. The light emitting device of claim 1, wherein the second electron transport layer is doped with at least one of Yb, li, liQ.
  3. 3. The light-emitting device according to claim 2, wherein the second electron transport layer is doped with Yb, and wherein a mass doping ratio of the Yb in the second electron transport layer satisfies [1%,10% ].
  4. 4. The light-emitting device according to claim 1 or 2, wherein the first electron-transporting layer has a thickness in the range of [10nm,20nm ], and the second electron-transporting layer has a thickness in the range of [1nm,20nm ].
  5. 5. The light-emitting device according to any one of claims 1 to 4, wherein a difference in energy levels between a LUMO energy level of the first electron-transporting layer and a LUMO energy level of the second electron-transporting layer satisfies less than 0.1eV.
  6. 6. The light-emitting device according to any one of claims 1 to 5, further comprising a cathode injection layer provided between the cathode and the second electron transport layer in a lamination direction of the anode and the first light-emitting layer.
  7. 7. The light-emitting device according to any one of claims 1 to 6, further comprising a first electron blocking layer provided between the first electron transport layer and the first light-emitting layer in a lamination direction of the anode and the first light-emitting layer.
  8. 8. The light-emitting device according to claim 7, further comprising a hole injection layer, a first hole transport layer, and a first hole blocking layer provided between the first light-emitting layer and the anode in the lamination direction, the hole injection layer being between the first hole transport layer and the anode, the first hole blocking layer being between the first light-emitting layer and the first hole transport layer.
  9. 9. The light-emitting device according to claim 8, further comprising a second light-emitting layer, a third electron-transporting layer, a second electron-blocking layer, a second hole-transporting layer; In the stacking direction, the third electron transport layer and the second electron blocking layer are located between the first hole transport layer and the second light emitting layer, the second electron blocking layer is located between the third electron transport layer and the second light emitting layer, and the third electron transport layer is located between the first hole transport layer and the second electron blocking layer; In the stacking direction, the second hole transport layer and the second hole blocking layer are located between the second light emitting layer and the hole injection layer, and the second hole transport layer is located between the second hole blocking layer and the hole injection layer.
  10. 10. The light-emitting device according to claim 9, further comprising a P-type carrier generation layer and an N-type carrier generation layer, wherein in the stacking direction, the P-type carrier generation layer is located between the first hole transport layer and the N-type carrier generation layer, and wherein the N-type carrier generation layer is located between the third electron transport layer and the P-type carrier generation layer.
  11. 11. The light-emitting device according to any one of claims 1 to 10, further comprising a light extraction layer located on a side of the cathode facing away from the second electron transport layer in a lamination direction of the anode and the first light-emitting layer.
  12. 12. A display panel, characterized in that the display panel comprises a substrate and a light emitting device according to any one of claims 1-11, which is provided on the substrate.
  13. 13. An electronic device comprising a housing and the display panel of claim 12, the display panel being disposed on the housing.

Description

Light emitting device, display panel and electronic apparatus Technical Field The present application relates to the field of display technologies, and in particular, to a light emitting device, a display panel, and an electronic apparatus. Background At present, an Organic Light-Emitting Diode (OLED) Light-Emitting device has been widely used in terminal display screens of mobile phones, tablets, computers and the like, and has remarkable advantages of high brightness, bright color, high contrast ratio and the like. Light emitting devices generally include an anode, a cathode, a light emitting layer, and an electron transport layer. Based on the requirement of low power consumption of the product, the electron transport layer is usually made of a material with excellent electron mobility, so as to reduce the driving voltage of the light emitting device. However, materials that exhibit excellent electron mobility tend to have a higher refractive index. The material with higher refractive index can cause serious surface plasmon (Surface Plasmon Polariton, SPP) loss between the electron transport layer and the cathode, so that some light waves are bound at the cathode and can not be emitted, and the luminous efficiency of the luminous device is affected. Disclosure of Invention The embodiment of the application provides a light emitting device, a display panel and electronic equipment, which can reduce power consumption and surface plasmon loss. In a first aspect, an embodiment of the present application provides a light emitting device, where the light emitting device includes an anode, a first light emitting layer, a first electron transport layer, a second electron transport layer, and a cathode that are stacked, the first light emitting layer, the first electron transport layer, and the second electron transport layer are all located between the anode and the cathode, the first light emitting layer is located between the first electron transport layer and the anode, the second electron transport layer is located between the cathode and the second electron transport layer, a refractive index of the first electron transport layer is greater than or equal to 1.8, and a refractive index of the second electron transport layer is less than or equal to 1.6. The light-emitting device provided by the application replaces the traditional single-layer electron transport layer with the double-layer electron transport structure comprising the first electron transport layer and the second electron transport layer, and the refractive index of the second electron transport layer is smaller than or equal to 1.6, so that the SPP loss between the cathode and the double-layer electron transport structure is reduced. Meanwhile, compared with the second electron transport layer, the refractive index of the first electron transport layer farther from the cathode is larger than or equal to 1.8, so that the first electron transport layer has higher electron mobility, the driving voltage of the light-emitting device is reduced, and the power consumption of the light-emitting device is reduced while the SPP loss of the light-emitting device is reduced. Compared with a light-emitting device with a similar structure but a single electron transport layer, the light-emitting device with a double electron transport structure has the advantages that the electron migration capability is kept through the first electron transport layer, the SPP loss is reduced through the second electron transport layer, the optical characteristics of the light-emitting device are improved, and meanwhile, the driving voltage of the light-emitting device can be kept unchanged remarkably. According to the first aspect, in a possible implementation manner of the present application, the second electron transport layer is doped with at least one of Yb, li, liQ to improve the electron mobility of the second electron transport layer, which is beneficial to further reduce the driving voltage of the light emitting device while reducing the SPP loss. According to a first aspect, in one possible implementation of the application, the second electron transport layer is doped with Yb, the mass doping ratio of Yb in the second electron transport layer being [1%,10% ], to obtain excellent electron mobility. According to a first aspect, in one possible implementation of the application, the first electron transport layer has a thickness in the range of [10nm,20nm ], and the second electron transport layer has a thickness in the range of [1nm,20nm ]. If the thicknesses of the first electron transport layer and the second electron transport layer are too thick, the stacked structure of the entire light emitting device may be too thick. If the thickness of the first electron transport layer is too small, the electron transport capability of the first electron transport layer may be affected, and thus the driving voltage of the light emitting device may be affected. If the th