Electroluminescence device and its preparation method

Abstract

The invention relates to an electroluminescence device and a manufacturing method thereof. The electroluminescence device comprises a substrate, a metal negative electrode, an electron transmission layer, a hole barrier layer, a luminescent layer, an electron barrier layer, a hole transmission layer, a hole injection layer and a metal positive electrode which are all laminated in sequence, wherein the electron transmission layer is made of low price state metallic compounds mixed with high price state metallic compounds, the high price state metallic compounds are molybdenum trioxide or vanadium pentoxide or tungsten trioxide, and the low price state metallic compounds are titanium dioxide or cadmium sulfide or cadmium selenide. According to the electroluminescence device, through manufacturing of the n-type electron transmission layer mixed with inorganic materials, high price state metallic oxide is doped into lower price state metallic compound materials, and thus exciton composition probability is improved and luminous efficiency is strengthened.

Description

【Technical field】 [0001] The invention relates to a bottom emission electroluminescence device and a preparation method thereof. 【Background technique】 [0002] In 1987, C.W.Tang and Van Slyke of Eastman Kodak Company in the United States reported a breakthrough in the research of organic electroluminescence. A high-brightness, high-efficiency double-layer small-molecule electroluminescent device was prepared using ultra-thin film technology. In this double-layer structure device, the brightness reaches 1000cd / m at 10V 2 , its luminous efficiency is 1.51lm / W, and its lifespan is more than 100 hours. In 1990, Burronghes et al. of the University of Cambridge proposed for the first time to use polymer conjugated polymer polyphenylene vinylene (PPV) to make polymer electroluminescence (EL) devices. Subsequently, the experimental group led by Professor Heeger of the University of California in the United States In 1991, the electroluminescent properties of polymers were furthe...

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Problems solved by technology

[0004] In traditional light-emitting devices, since the transport rate of electrons is two orders of magnitude lower than that of holes (the hole transport rate is generally 10 -3 cm 2 V -1 S -1 , the electron transfer rate is generally 10 -5 cm 2 V -1 S -1 ), this difference in rate often leads to a low probability of exciton recombination. At the same time, the current electron injection layer used in organic electroluminescence is generally LiF, and if the film thickness of this material is too thick, the resistance will rise sharply, and if it is too thin, the resistance will increase sharply. It will not play a buffer role, and eventually the efficiency of the device will decrease. In addition, if the thickness is too thin, the distance between the active layer and the metal cathode will be too close, which will cause electronic quenching and affect the energy conversion efficiency. At the same time, the evaporation of LiF The plating temperature is about 800-1000 degrees, which will cause the degassing process of the vacuum equipment during the evaporation process, so that the vacuum degree will suddenly rise, and impurities will be introduced, which is not conducive to evaporation. At the same time, the transmission rate of most electron transport materials is not ideal. , which is quite different from the hole transport rate, and cannot effectively improve the recombination probability of excitons

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