Suppressing thermal quenching of lead halide perovskite nanocrystals by constructing a wide-bandgap surface layer for achieving thermally stable white light-emitting diodes

Qinggang Zhang; Mengda He; Qun Wan; Weilin Zheng; Mingming Liu; Congyang Zhang; Xinrong Liao; Wenji Zhan; Long Kong; Xiaojun Guo; Liang Li

doi:10.1039/d1sc06554h

Suppressing thermal quenching of lead halide perovskite nanocrystals by constructing a wide-bandgap surface layer for achieving thermally stable white light-emitting diodes

Chem Sci. 2022 Feb 28;13(13):3719-3727. doi: 10.1039/d1sc06554h. eCollection 2022 Mar 30.

Authors

Qinggang Zhang^{1

2}, Mengda He¹, Qun Wan¹, Weilin Zheng¹, Mingming Liu¹, Congyang Zhang¹, Xinrong Liao¹, Wenji Zhan¹, Long Kong¹, Xiaojun Guo², Liang Li^{1

3}

Affiliations

¹ School of Environmental Science and Engineering, Shanghai Jiao Tong University Shanghai 200240 China liangli117@sjtu.edu.cn.
² Department of Electronic Engineering, School of Electronics Information and Electrical Engineering, Shanghai Jiao Tong University Shanghai 200240 China.
³ Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, Shanghai Jiao Tong University Shanghai 200240 China.

Abstract

Lead halide perovskite nanocrystals as promising ultrapure emitters are outstanding candidates for next-generation light-emitting diodes (LEDs) and display applications, but the thermal quenching behavior of light emission has severely hampered their real-world applications. Here, we report an anion passivation strategy to suppress the emission thermal quenching behavior of CsPbBr₃ perovskite nanocrystals. By treating with specific anions (such as SO₄ ^2-, OH^-, and F^- ions), the corresponding wide-bandgap passivation layers, PbSO₄, Pb(OH)₂, and PbF₂, were obtained. They not only repair the surface defects of CsPbBr₃ nanocrystals but also stabilize the phase structure of the inner CsPbBr₃ core by constructing a core-shell like structure. The photoluminescence thermal resistance experiments show that the treated sample could preserve 79% of its original emission intensity up to 373 K, far superior to that (17%) of pristine CsPbBr₃. Based on the thermally stable CsPbBr₃ nanocrystals, we achieved temperature-stable white LED devices with a stable electroluminescence spectrum, color gamut and color coordinates in thermal stress tests (up to 373 K).