Feldmann Sascha, Gangishetty Mahesh K, Bravić Ivona, Neumann Timo, Peng Bo, Winkler Thomas, Friend Richard H, Monserrat Bartomeu, Congreve Daniel N, Deschler Felix
Cavendish Laboratory, University of Cambridge, Cambridge CB30HE, U.K.
Rowland Institute, Harvard University, Cambridge, Massachusetts 02142, United States.
J Am Chem Soc. 2021 Jun 16;143(23):8647-8653. doi: 10.1021/jacs.1c01567. Epub 2021 May 16.
Nanocrystals based on halide perovskites offer a promising material platform for highly efficient lighting. Using transient optical spectroscopy, we study excitation recombination dynamics in manganese-doped CsPb(Cl,Br) perovskite nanocrystals. We find an increase in the intrinsic excitonic radiative recombination rate upon doping, which is typically a challenging material property to tailor. Supported by calculations, we can attribute the enhanced emission rates to increased charge carrier localization through lattice periodicity breaking from Mn dopants, which increases the overlap of electron and hole wave functions locally and thus the oscillator strength of excitons in their vicinity. Our report of a fundamental strategy for improving luminescence efficiencies in perovskite nanocrystals will be valuable for maximizing efficiencies in light-emitting applications.
基于卤化物钙钛矿的纳米晶体为高效照明提供了一个很有前景的材料平台。利用瞬态光谱技术，我们研究了锰掺杂的CsPb(Cl,Br)钙钛矿纳米晶体中的激发复合动力学。我们发现掺杂后本征激子辐射复合速率增加，而这通常是一种难以调控的材料特性。在计算的支持下，我们可以将发射速率的提高归因于Mn掺杂剂破坏晶格周期性导致电荷载流子局域化增加，这局部增加了电子和空穴波函数的重叠，从而增加了其附近激子的振子强度。我们关于提高钙钛矿纳米晶体发光效率的基本策略的报告对于最大化发光应用中的效率将具有重要价值。
