准二维钙钛矿相分布调控及其蓝光发光二极管

Abstract： Quasi-two-dimensional perovskites have been used to construct high-efficiency perovskite light-emitting diodes (PeLEDs) due to their multi-quantum well structure， cascade energy transfer and high luminescence quantum efficiency， which have broad application prospects in the fields of display and lighting.Due to the non radiative re• combination caused by a large number of small n-phases in quasi-two-dimensional perovskite， blue light PeLEDs face problems such as low energy transfer efficiency and unstable emission spectra， and their performance lags be• hind red and green light devices.This article introduces poly (4-styrenesulfonic acid sodium) and cesium chloride to the hole transport layer to synergistically regulate the crystallization of perovskite thin films by affecting the nucle • ation and growth process of perovskite.The phase distribution is controlled， effectively suppressing the small nphase components in perovskite and improving energy transfer efficiency， and reducing the trap state density.As a result， non radiative recombination is significantly suppressed.In addition， chloride ions diffuse into the perovskite layer and tune the blue emission of the thin film through ion exchange.The optimized blue PeLED device has an emission spectrum located at 488 nm， a maximum brightness of 2 772 cd/m 2 ， and a maximum external quantum effi• ciency of 4. 9%.This work provides an effective method for achieving efficient and spectral stable blue PeLED .Key words： blue perovskite light-emitting diodes； quasi-two-dimensional perovskite； phase distribution regulation； hole transport layer 文章编号： 1000