Organic electroluminescent device and electronic equipment

Abstract

The invention provides an organic electroluminescent device and electronic equipment. The organic electroluminescent device comprises a substrate, an anode layer, a light emitting layer, a first electron transport layer, a second electron transport layer and a cathode layer, wherein the anode layer, the light emitting layer, the first electron transport layer, the second electron transport layer and the cathode layer are sequentially formed on the substrate, and the difference of lowest unoccupied molecular orbital energy levels of the first electron transport layer and the second electron transport layer is greater than or equal to -0.2eV and is less than or equal to 0.2eV. The organic electroluminescent device can adjust a resonant cavity of the top-emission organic electroluminescent device through the second electron transport layer, and respectively adjusts the recombination positions of excitons of three-primary colors RGB through the second electron transport layer, thereby achieving the best device performance.

Description

technical field [0001] The invention relates to the field of display technology, in particular to an organic electroluminescent device and electronic equipment. Background technique [0002] Organic electroluminescent (OLED) devices have the advantages of low power consumption, light weight, high brightness, wide field of view, and fast response. They are widely used in portable electronic devices, wearable electronic devices, automotive electronic devices, and many other devices, and are expected to become the next generation The mainstream technology of flat panel display. [0003] An OLED device generally includes an anode layer (Anode), a cathode layer (Cathode) on a substrate, and an emissive layer (EML) between the anode layer and the cathode layer. The principle of luminescence is: holes injected from the anode layer and electrons injected from the cathode layer combine to form excitons in the recombination area in the light-emitting layer, and the excitons decay and...

AI Technical Summary

Problems solved by technology

from figure 1 It can be seen that the LUMO energy levels of the cathode layer and the electron transport layer are close, both about -2.6eV, and the electrons in the cathode layer can be injected into the electron transport layer smoothly; the light emitting layer includes the first light emitting material and the second light emitting material, Among them, the LUMO energy level of the first light-emitting material is -2.1eV, the LUMO energy level of the second light-emitting material is -2.9eV, the LUMO energy level of the light-emitting layer changes greatly, and the difference between the LUMO energy level of the electron transport layer is too large, To inject electrons from the electron transport layer into the light-emitting layer needs to overcome a large potential barrier, and the electron injection efficiency is low

[0006] Therefore, when the LUMO energy level of the light-emitting layer is too deep or too shallow, the difference between the LUMO energy levels of the light-emitting layer and the cathode layer is too large. The transmission performance is not good, and the voltage of the device increases, so the thickness of the electron transport layer should not be too thick

Since the thickness of the electron transport layer is not suitable to be too thick, the electron transport layer cannot be used to adjust the resonant cavity of the top-emitting OLED device, and at the same time, it may cause the exciton recombination region to shift, thereby making the luminous efficiency not high

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