Search

JP-2026074761-A - Organic light-emitting devices, display devices, in-vehicle displays, electronic devices and vehicles

JP2026074761AJP 2026074761 AJP2026074761 AJP 2026074761AJP-2026074761-A

Abstract

[Problem] To provide an organic light-emitting device, display device, electronic device, and in-vehicle display with improved luminous efficiency, and a vehicle using the in-vehicle display. [Solution] Between the anode electrode 11 and cathode electrode 12, which are provided opposite each other, there is an interference reflection section 30 together with a light-emitting structure section 20 including a light-emitting layer 24. The interference reflection section 30 is formed in contact with the anode electrode 11 and includes a plurality of p-type low refractive index layers 31 having p-type conductivity and a low refractive index as a first charge generation layer having a first conductivity type and a first refractive index, and a plurality of n-type high refractive index layers 32 having n-type conductivity and a high refractive index as a second charge generation layer having a second conductivity type and a second refractive index. In the interference reflection section 30, the plurality of p-type low refractive index layers 31 and the plurality of n-type high refractive index layers 32 are alternately stacked. [Selection Diagram] Figure 1

Inventors

  • 濱田 継太
  • 森 茂

Assignees

  • Ｔｉａｎｍａ Ｊａｐａｎ株式会社

Dates

Publication Date
20260507
Application Date
20241021

Claims (13)

  1. A first electrode and a second electrode are provided opposite each other, The first electrode and the second electrode are provided with an organic compound layer having at least a light-emitting layer and an interference-reflecting portion, The aforementioned interference reflection section is Multiple first charge generation layers having a first conductivity type and a first refractive index, and multiple second charge generation layers having a second conductivity type and a second refractive index are alternately stacked. Formed in contact with either the first electrode or the second electrode, Organic light-emitting device.
  2. The first charge generation layer is a first organic material layer exhibiting electron-accepting properties, obtained by doping a charge transport material with a first conductive impurity. The second charge generation layer is a second organic material layer exhibiting electron-donating properties, which is doped with a second conductive impurity to the charge transport material. The organic light-emitting apparatus according to claim 1.
  3. The first electrode and the second electrode are provided with a hole injection layer, a hole transport layer, an electron injection layer, and an electron transport layer, The interference reflection portion is formed at a position different from the hole injection layer, the hole transport layer, the electron injection layer, and the electron transport layer. The organic light-emitting apparatus according to claim 1.
  4. The interference reflection portion is formed in contact with the hole injection layer or the electron injection layer, The organic light-emitting apparatus according to claim 3.
  5. The aforementioned light-emitting layer is A first light-emitting layer formed in the first region and exhibiting a visible light spectrum of the first color, A second light-emitting layer formed in the second region, which exhibits a visible light spectrum of a second color having a different emission wavelength from the first color, A third light-emitting layer is formed in the third region and exhibits a visible light spectrum of a third color having an emission wavelength different from that of the first and second colors, The aforementioned interference reflection section is A first interference reflection portion for the visible light spectrum of the first color is formed in the first region in contact with the first electrode or the second electrode, A second interference reflection portion for the visible light spectrum of the second color is formed in the second region in contact with the first electrode or the second electrode, A third interference reflection portion for the visible light spectrum of the third color is formed in the third region in contact with the first electrode or the second electrode. The organic light-emitting apparatus according to claim 1.
  6. The aforementioned light-emitting layer is A first light-emitting layer formed in the first region and exhibiting a visible light spectrum of the first color, A second light-emitting layer formed in the second region, which exhibits a visible light spectrum of a second color having a different emission wavelength from the first color, A third light-emitting layer is formed in the third region and exhibits a visible light spectrum of a third color having an emission wavelength different from that of the first and second colors, The aforementioned interference reflection section is A first interference reflection portion for the visible light spectrum of the first color is formed in contact with the first electrode or the second electrode, A second interference reflection portion for the visible light spectrum of the second color is formed in contact with the first interference reflection portion. A third interference reflection portion is formed in contact with the second interference reflection portion for the visible light spectrum of the third color. The organic light-emitting apparatus according to claim 1.
  7. The device comprises a light extraction layer formed on the outside of the first electrode and the second electrode, The aforementioned light extraction layer is A high refractive index region that overlaps with the light-emitting layer in a direction perpendicular to the plane of the light-emitting layer, A low refractive index region that does not overlap with the light-emitting layer in a direction perpendicular to the plane of the light-emitting layer, The low refractive index region has a curved thickness that is parallel to the plane of the light-emitting layer and gradually decreases in the direction from farther away from the light-emitting layer towards the nearer layer. The organic light-emitting apparatus according to claim 1.
  8. The first electrode, the second electrode, the light-emitting layer, and the interference reflection portion are formed as a microlens array having a maximum portion, a slanted portion, and a minimum portion. The organic light-emitting apparatus according to claim 1.
  9. A portion or all of the aforementioned organic compound layer is positioned above the inclined portion of the pixel definition layer. The interference reflection portion is formed in contact with the inclined portion of the pixel definition layer, The organic light-emitting apparatus according to claim 1.
  10. A display device comprising an organic light-emitting device according to any one of claims 1 to 9.
  11. An in-vehicle display equipped with the display device described in claim 10.
  12. An electronic device comprising the display device described in claim 10.
  13. A vehicle equipped with an in-vehicle display as described in claim 11.

Description

This disclosure relates to organic light-emitting devices, display devices, in-vehicle displays, electronic devices, and vehicles. As organic light-emitting devices using organic light-emitting materials, those that improve luminescence efficiency and monochromaticity through the microcavity effect are known. In the organic light-emitting device 501 having the element structure shown in Figure 30(A), a microcavity is formed by an anode electrode 511 and a cathode electrode 512 provided opposite each other on the circuit board 510. When the anode electrode 511 is a reflective electrode using a metal electrode and the cathode electrode 512 is a translucent electrode, the luminescence intensity depends on the distance DA between the anode electrode 511 and the center of the light-emitting layer 513, and the distance DB between the cathode electrode 512 and the center of the light-emitting layer 513. Zones Z01, Z02, and Z03 shown in Figure 30(B) represent zones where a high microcavity effect can be obtained based on the distances DA and DB, based on optical simulations. Figure 30(B) shows the optical simulation results when the emission main wavelength is 460 nm. When considering only the microcavity effect, the emission intensity shows a highest first peak in zone Z01, followed by similarly high second peaks in zones Z02 and Z03. In contrast, the experimental results shown in Figure 31 show that the emission intensity has a peak in zone Z01 indicated by curve CU11, a peak in zone Z02 indicated by curve CU12, and a peak in zone Z03 indicated by curve CU13. The peak of luminescence intensity indicated by curve CU12 is higher than the peak indicated by curve CU11 in Figure 31. The peak of luminescence intensity indicated by curve CU13 is higher than the peak indicated by curve CU12. Therefore, the simulation results considering only the microcavity effect are inconsistent with the experimental results. When the anode electrode 511 of the organic light-emitting device 501 is constructed using a metal electrode containing silver (Ag) or the like as the reflective electrode, it is necessary to consider optical loss known as surface plasmon loss. When an optical simulation considering optical loss along with the microcavity effect is performed on the results shown in Figure 30(B), the peak of emission intensity appearing in zone Z03 is higher than the peak of emission intensity appearing in zone Z02. Furthermore, the peak of emission intensity appearing in zone Z02 is higher than the peak of emission intensity appearing in zone Z01. In this case, the optical simulation results are consistent with the experimental results shown in Figure 31. Surface plasmons are waves of electrons vibrating on the surface of a conductor. In an organic light-emitting device 501 including an anode electrode 511 using a metal electrode, light emission from radiant dipoles produced by molecular excitons in the light-emitting layer couples with the electron vibrations of the reflective electrode, causing optical loss. While the external quantum efficiency obtained by optical simulation is calculated by multiplying carrier balance, exciton generation rate, radiant quantum efficiency, and light extraction efficiency, incorporating a parcel factor into the radiant quantum efficiency allows for calculations that consider optical loss. Top-emission type organic light-emitting diode (OLED) displays using an organic light-emitting device 501 that extracts light from the cathode electrode 512 side suppress light loss by increasing the distance DA from the anode electrode 511 to the center of the light-emitting layer 513. Furthermore, to achieve higher brightness and longer lifespan, a tandem structure is used, in which multiple light-emitting layers, such as the two light-emitting layers 513A and 513B shown in Figure 32, are provided between the opposing anode electrode 511 and cathode electrode 512. However, if the tandem structure has the same overall film thickness as the single structure, the distance between the lower light-emitting layer 513A and the reflective anode electrode 511 becomes shorter. Therefore, for green and blue light colors, the luminous efficiency of the tandem structure does not reach twice that of the single structure. Thus, improving luminous efficiency by replacing the reflective electrode using the anode electrode 511 is being considered. Patent Document 1 discloses a dielectric mirror that acts as an optical resonator to enhance light of a specific wavelength. Patent Document 2 discloses a light-emitting device having a low refractive index layer containing an organic compound along with a light-emitting layer. Patent Document 3 discloses an optical component in which high refractive index layers and low refractive index layers are alternately and repeatedly laminated. Japanese Patent Publication No. 2007-317591Japanese Patent Publication No. 2023-4940U.S. Patent Application Publication No. 2015/0041768 This is a sche