Unveiling the photoluminescence regulation of colloidal perovskite quantum dots via defect passivation and lattice distortion by potassium cations doping: Not the more the better
Unveiling the photoluminescence regulation of colloidal perovskite quantum dots via defect passivation and lattice distortion by potassium cations doping: Not the more the better
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DOI：
10.1016/j.jcis.2021.03.128
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发表时间：
2021-04-09
影响因子：
9.9
通讯作者：
Zhao, Guangjiu
中科院分区：
文献类型：
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作者：
Chu, Ya;Wang, Chao;Zhao, Guangjiu
在这项工作中，我们首次证明了钾离子掺杂对CH3NH3PbBr3 （CH3NH3+=MA(+)）胶体钙钛矿量子点（QDs）光致发光（PL）调控的影响与其他碱离子掺杂效应有显著不同。随着其他碱阳离子掺杂量的增加，PL强度普遍增强。本文揭示了掺钾钙钛矿量子点的PL首先受到钾离子掺杂的促进，然后随着钾离子掺杂量的进一步增加而受到抑制。此外，我们还证明，除了初始掺杂引起的缺陷钝化和八面体结构畸变外，大量掺杂后的陷阱态快速捕获了多余的光生电子，从而导致了PL抑制现象。同时，MA(x)K(1-x)PbBr(3)的比激发态瞬态吸收和寿命也证实了适度钾离子掺杂引起的缺陷钝化和晶格畸变增强了辐射复合过程。此外，胶体钙钛矿量子点的发光在300 nm -600 nm波长范围内可由橙色调到青色，并表现出较好的稳定性。(c) 2021爱思唯尔公司版权所有。
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(x)K(1-x)PbBr(3) 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.(c) 2021 Elsevier Inc. All rights reserved.