Liaocheng University and Soochow University collaborate to make progress in the research field of bl

Recently, Professor Wang Wenjun's research team from the School of Physical Science and Information Engineering of Liaocheng University cooperated with the research team of Professor Tang Jianxin of Soochow University to make breakthroughs in the field of efficient and stable blue perovskite light emitting diodes.

The relevant research results, titled Manipulating Crystallization Dynamics for Efficient and Spectrally Stable Blue Perovskite Light-Emitting Diodes, were published in Laser Photonics Reviews (Laser and Photonics Review, impact factor 10.947, one of the Top journals in District 1 of the Chinese Academy of Sciences). This is the first time that teachers and students of our school have published it in this journal with the first signatories.

Metal halide perovskites have the advantages of high fluorescence quantum yield, solution preparation, and high color purity. They have broad application prospects in lighting and high-performance displays. In recent years, the external quantum efficiency of red and green perovskite light emitting diode (PeLEDs) devices has hit record highs, and has almost reached the optical coupling limit of their materials. However, poor spectral stability and low external quantum efficiency still restrict the development of blue PeLEDs.

Aiming at the problem that mixed halogens are prone to phase separation under an electric field, this paper proposes a method to control the crystallization kinetics to improve perovskite film formation and halogen distribution by diluting the concentration of precursor. The results show that the homogenized halogen distribution reduces the non-radiative recombination rate and suppresses ion migration. The prepared device achieves an external quantum efficiency of 8.5%, and achieves stable blue light emission at 482nm (as shown in Figure 1). This work provides a simple solution to the current common phase separation problem in blue light. solution.

The first author of this paper is Cao Longxue, a master's student in 2020. The corresponding authors are Professor Wang Wenjun of our college, Professor Tang Jianxin of Suzhou University and Dr. Shenyang. Professor Li Shuhong and Associate Professor Liu Yunlong participated in part of the research work. This work is supported by the National Natural Science Foundation of China, the Liaocheng University Project and the Taishan Scholars Special Construction Project Fund of Shandong Province.