OLED (Organic Light-Emitting Diode) and fabrication method thereof

Abstract

The invention provides an OLED (Organic Light-Emitting Diode) and a fabrication method thereof. The OLED at least comprises a luminous layer between an anode and a cathode and also comprises at least two electron transfer layers arranged between the luminous layer and the cathode and an N-type doped layer arranged between each two adjacent electron transfer layers. In the OLED and the fabrication method thereof, provided by the invention, at least two electron transfer layers are adopted, the N-type doped layer is arranged between each two adjacent electron transfer layers, an electron transfer material and an N-type doped agent are sequentially subjected to evaporation, an effect similar to N-type doping is formed through an interface doping effect and diffusion of the N-type doped agent, electron injection and transfer capability is improved, so that carrier concentration is balanced, exciton utilization rate is improved, and the photoelectric performance of the OLED is improved.

Description

technical field [0001] The invention relates to the field of display technology, in particular to an organic electroluminescent device and a preparation method thereof. Background technique [0002] In OLED (Organic Light-Emitting Diode, organic electroluminescent device), the hole mobility of the hole transport material is much greater than the electron mobility of the electron transport material, which causes an imbalance in the number of electrons and holes in the recombination region , which reduces the recombination probability of excitons, resulting in low current efficiency and power efficiency of OLED. [0003] In the prior art, in order to improve the injection and transport capability of electrons in the OLED, the following two methods are usually adopted: [0004] The method of using N-type doping in the electron transport layer: such as figure 1 As shown, the N-type dopant 11 is doped in the electron-transport material 12 according to a certain ratio, which is ...

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Problems solved by technology

[0004] The method of using N-type doping in the electron transport layer: such as figure 1 As shown, the N-type dopant 11 is doped in the electron-transport material 12 according to a certain ratio, which is realized by co-evaporation, but requires an accurate doping ratio of the N-type dopant and the electron-transport material. It is difficult to control in the operation, and the repeatability of the experiment is also poor;

[0005] The method of double electron injection layer: although it can reduce the injection barrier of electrons and facilitate the direct injection of electrons, it cannot improve the mobility of electrons in the transport layer

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