Unveiling the photoluminescence regulation of colloidal perovskite quantum dots via defect passivation and lattice distortion by potassium cations doping: Not the more the better

Ya Chu; Chao Wang; Linlin Ma; Xia Feng; Beibei Wang; Yanqing Wu; Yan Jia; Mingshui Zhang; Yan Sun; Haoyue Zhang; Guangjiu Zhao

doi:10.1016/j.jcis.2021.03.128

Unveiling the photoluminescence regulation of colloidal perovskite quantum dots via defect passivation and lattice distortion by potassium cations doping: Not the more the better

J Colloid Interface Sci. 2021 Aug 15:596:199-205. doi: 10.1016/j.jcis.2021.03.128. Epub 2021 Mar 24.

Authors

Ya Chu¹, Chao Wang¹, Linlin Ma¹, Xia Feng¹, Beibei Wang¹, Yanqing Wu², Yan Jia², Mingshui Zhang¹, Yan Sun¹, Haoyue Zhang¹, Guangjiu Zhao³

Affiliations

¹ Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University, Tianjin 300354, China.
² State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China.
³ Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University, Tianjin 300354, China. Electronic address: gjzhao@tju.edu.cn.

PMID: 33845227
DOI: 10.1016/j.jcis.2021.03.128

Abstract

In this work, we have first demonstrated that the potassium cation doping effect on photoluminescence (PL) regulation of CH₃NH₃PbBr₃ (CH₃NH₃⁺=MA⁺) colloidal perovskite quantum dots (QDs) is significantly different from the other alkali cation doping effects. The PL intensity will be generally enhanced with the increase doping amounts of other alkali cations. Herein, we have unveiled that the PL of the potassium-doped perovskite QDs is initially prompted by the potassium ions doping and then inhibited with further growing doping amount of the potassium ions. Furthermore, we have also demonstrated that the PL inhibition phenomenon is ascribed as quick trapping of redundant photogenerated electrons by the trap states after huge amount doping besides defect passivation and octahedral structure distortion induced by the initial doping. At the same time, the specific excited state transient absorption and the lifetime of MA_xK_1-xPbBr₃ also confirm that the radiation recombination process is enhanced via defect passivation and lattice distortion, which is induced by moderate potassium cations doping. In addition, the PL of colloidal perovskite quantum dots can be adjusted from orange to cyan within the wavelength range of 300 nm - 600 nm and exhibit better stability.

Keywords: Defect passivation; Lattice distortion; PL regulation; Perovskite QDs; Potassiumcations doping.