Quantum dot light-emitting diode (QLED) and preparation method therefor, and display

Abstract

The invention discloses a quantum dot light-emitting diode (QLED) and a preparation method therefor, and a display, and aims to block electron injection in the QLED, strengthen carrier injection balance in the QLED, improve optical output efficiency and resistance to water and oxygen erosion of a device in the QLED, and improve the luminance, working efficiency and service life of the QLED. The invention provides the QLED, wherein the QLED comprises a first electrode layer, a second electrode layer, a hole transport layer arranged between the first electrode layer and the second electrode layer, a quantum dot light-emitting layer arranged between the hole transport layer and the second electrode layer, an electron transport layer arranged between the quantum dot light-emitting layer and the second electrode layer, and an electron buffer layer arranged between the electron transport layer and the second electrode layer.

Description

technical field [0001] The present application relates to the technical field of quantum dot electroluminescence, in particular to a quantum dot electroluminescence diode, a preparation method thereof, and a display. Background technique [0002] Quantum dot light-emitting diode (QLED) is a device in which current directly excites quantum dots to emit light. QLED combines the advantages of quantum dot materials, such as quantum dots with tunable emission wavelength, narrow line width (15-30nm), high efficiency (70%-100%), good optical, thermal and chemical stability, and OLED film-forming process, It is expected to be applied to a new generation of flat panel display with high color quality and low power consumption, and has attracted more and more people's attention. However, taking red QLED as an example, its external quantum efficiency (EQE) reaches 20.5%, and its maximum brightness is >10 4 cd / m 2 , service life up to 10Wh (T50100cd / m 2 ), there is a certain gap w...

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Problems solved by technology

The HOMO energy level of organic hole transport materials is in the range of -5.0eV to -6.0eV, and the valence band energy level of quantum dots is in the range of -6.0eV to -7.0eV, and there is a large hole injection barrier; in addition, most The mobility of the organic hole transport material is -4 cm 2 V -1 S -1 , is not conducive to the injection and transport of holes in the device, which will lead to the imbalance of electron and hole injection in the device, and consume energy in the form of heat, and the organic material is thermally aged and easily corroded by water and oxygen in the environment, which affects the device efficiency and life

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