Composition for electron transport layer, electron transport layer and photoelectric device

Abstract

The invention discloses a composition for an electron transport layer, the electron transport layer and a photoelectric device, and belongs to the technical field of display, the composition comprises8-hydroxyquinoline-lithium and a composite material; the composite material comprises at least two electron transport materials of which the LUMO energy levels are -2.95eV to -2.70eV; and the mass percentage content of the 8-hydroxyquinoline-lithium in the composition is 40%-60%. The photoelectric device containing the composition enables electron injection to be faster at high temperature and current carrier recombination to be more balanced, so that the problem of short service life at high temperature is solved. Moreover, the electron transport material with a reasonable energy level structure is adopted, so that the energy level in each layer of the photoelectric device can form a stepped barrier, the injection barrier and the driving voltage can be reduced, and meanwhile, the reasonable carrier mobility is matched, so that the carrier recombination is more balanced, and the luminous efficiency and the service life of the device can be effectively improved.

Description

technical field [0001] The invention relates to the field of display technology, in particular to a composition for an electron transport layer, an electron transport layer and a photoelectric device. Background technique [0002] Organic Light Emitting Diode (OLED) display panel is a self-luminous display panel. OLED display panel has the advantages of thinness, high brightness, low power consumption, wide viewing angle, high response speed and wide operating temperature range. It is increasingly used in various high-performance display fields. Optoelectronic devices such as organic electroluminescent devices generally have a multi-layer structure. Various auxiliary functional layers besides the light-emitting layer also play a vital role in device performance. A reasonable device structure can effectively improve the performance of the device. Electron injection Layers, electron-transporting layers, hole-blocking layers, light-emitting layers, electron-blocking layers, ho...

AI Technical Summary

Problems solved by technology

With the development of OLED materials, organic materials that meet the performance requirements of OLED display panels tend to be electron-transporting. At room temperature, electron injection materials have no obvious impact on life, but at high temperatures, electron injection is slower than electron migration, resulting in electron transport. There is accumulation on the cathode side, and the electronic materials are easy to age, resulting in a shortened life of the OLED display panel

[0004] In addition, the light-emitting region of the device structure is close to the interface between the light-emitting layer and the hole, which is biased towards the electronic system. During the aging process of the life, the excitons have a greater impact on the interface on the HT side, resulting in damage to the interface, which affects the carrier injection. Affect the recombination of excitons, the efficiency is reduced, the brightness decays faster, and finally the life is poor

At present, an electron transport (ET) material and 8-hydroxyquinoline-lithium (Liq) doping technology are mostly used to solve the problem of electron injection and transport. The advantage of this structure is that the structure is relatively simple, but it has high requirements for ET materials and has high Electron mobility is conducive to improving device efficiency but leads to poor life. Although low electron mobility can guarantee life, it will lead to low device efficiency and rapid life decay at high temperatures.

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