A composition for electron transport layer, electron transport layer and optoelectronic device

Abstract

The invention discloses a composition for an electron transport layer, an electron transport layer and an optoelectronic device, belonging to the technical field of display. The composition comprises 8-hydroxyquinoline-lithium and a composite material; the composite material comprises at least two An electron transport material with a LUMO energy level of -2.95--2.70eV; the mass percentage content of 8-hydroxyquinoline-lithium in the composition is 40%-60%. The optoelectronic device containing the above composition enables faster electron injection and more balanced carrier recombination at high temperature, thereby improving the problem of short life at high temperature. In addition, by using electron transport materials with a reasonable energy level structure in the present invention, the energy levels in each layer of the optoelectronic device can form a stepped barrier, which can reduce the injection barrier and driving voltage. The carrier recombination is more balanced, which can effectively improve the luminous efficiency and lifetime of the device.

Description

technical field [0001] The present invention relates to the field of display technology, in particular to a composition for an electron transport layer, an electron transport layer and an optoelectronic 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 more and more used in various high-performance display fields. Optoelectronic devices such as organic electroluminescent devices are generally multi-layered structures. Various auxiliary functional layers other than the light-emitting layer also play a crucial role in the performance of the device. A reasonable device structure can effectively improve the performance of the device. Electron injection Layers, electron transport layers, hole blocking layers, light emitting layers, elec...

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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