北京大学徐东升团队报道了通过锑掺杂引发二维卤化钠钙钛矿中的强自陷激子发射。 相关研究成果于2021年1月15日发表在国际顶尖学术期刊《德国应用化学》。

近年来，层状双钙钛矿结构（LDPs）中发现了软晶格和强激子-声子耦合，因此LDP是一类很有前途的自陷激子发射材料，在固体照明领域有着广泛的应用前景。然而，目前发现的具有优异STE发射特性的LDPs还很少，其光电特性尚不清楚。

在三维Cs  2  NaInCl  6的基础上，采用降维和Sb掺杂相结合的方法，合成了两种具有单层和双层无机片的二维衍生物（PEA）4  NaInCl  8  : Sb（PEA=苯乙胺）和（PEA）2  CsNaInCl  7  : Sb。首次在常温常压下获得了明亮的宽带发射，其光致发光量子效率（PLQE）分别为48.7%（mono‐）和29.3%（bi‐），优于目前已知的LDPs。光谱表征和激发态的第一性原理计算表明，宽带发射源于被引入的 [SbCl  6  ] ^3‐八面体俘获的STEs。

研究结果为设计宽带发射的LDPs提供了重要的启示。

附：英文原文

Title: Strong Self‐Trapped Exciton Emissions in Two‐dimensional Na‐In Halide Perovskites Triggered by Antimony Doping

Author: Yu Zhang, Xingyi Liu, Huaiyang Sun, Jinxia Zhang, Xiaowen Gao, Chuang Yang, Qi Li, Hong Jiang, Juan Wang, Dongsheng Xu

Issue&Volume: 15 January 2021

Abstract: Soft lattice and strong exciton‐phonon coupling have been demonstrated in layered double perovskites (LDPs) recently, therefore LDP represents a promising class of compounds as excellent self‐trapped excitons (STEs) emitters for applications in the field of solid‐state lighting. However, few LDPs with outstanding STE emissions have been discovered, and their optoelectronic properties are still unclear. Based on the three‐dimensional (3D) Cs  2  NaInCl  6  , we synthesized two 2D derivatives (PEA)  4  NaInCl  8  : Sb (PEA = phenethylamine) and (PEA)  2  CsNaInCl  7  : Sb with monolayer and bilayer inorganic sheets by a combination of dimensional reduction and Sb‐doping. Bright broadband emissions were obtained for the first time under ambient temperature and pressure, with photoluminescence quantum efficiency (PLQE) of 48.7% (mono‐) and 29.3% (bi‐), superior to current known LDPs. Spectroscopic characterizations and first‐principles calculations of excited state indicate the broadband emissions originate from STEs trapped at the introduced [SbCl  6  ]  3‐  octahedron. Our results provide important insights for designing LDPs with broadband emissions.

DOI: 10.1002/anie.202015873

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202015873