Wang Xiaoyu, Shen Qibin, Chen Yansong, Ali Nasir, Ren Ziyang, Bi Gang, Wu Huizhen
Zhejiang Province Key Laboratory of Quantum Technology and Devices, Department of Physics, and State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou, 310027, PR China.
School of Information & Electrical Engineering, Zhejiang University City College, Hangzhou, Zhejiang 310015, PR China.
Nanoscale. 2021 Sep 23;13(36):15285-15291. doi: 10.1039/d1nr04635g.
The toxicity of Pb in conventional perovskites impedes the commercialization of their optoelectronic devices. Therefore, the search for comparable Pb-free perovskites is vital and needs urgent attention. Herein, for the first time, we successfully synthesize the Sn(II)-doped Pb-free zinc-based perovskite variant CsZnCl. The influence of doping is investigated both experimentally and theoretically. Broad bright red emission with a large Stokes shift is observed and attributed to the self-trapped exciton (STE) emission of the doped disphenoidal [SnCl] units in the host matrix, from P to S. Temperature-dependent photoluminescence (PL) shows a peak split at cryogenic temperature, which is ascribed to the Jahn-Teller effect of the P state. Theoretical study reveals that the impurity states of Sn shrink the bandgap and localize the band edges, and distortion of [SnCl] under excitation ultimately leads to the STE emission. This work is significant for STE emission studies and will pave a way for Pb-free perovskite variants in illumination applications.
传统钙钛矿中铅的毒性阻碍了其光电器件的商业化。因此，寻找可比的无铅钙钛矿至关重要且亟待关注。在此，我们首次成功合成了掺锡（II）的无铅锌基钙钛矿变体CsZnCl。通过实验和理论研究了掺杂的影响。观察到具有大斯托克斯位移的宽亮红色发射，并归因于主体基质中掺杂的双楔形[SnCl]单元从P到S的自陷激子（STE）发射。温度相关的光致发光（PL）在低温下显示出峰分裂，这归因于P态的 Jahn-Teller 效应。理论研究表明，Sn的杂质态使带隙变窄并使带边缘局域化，激发下[SnCl]的畸变最终导致STE发射。这项工作对STE发射研究具有重要意义，并将为无铅钙钛矿变体在照明应用中铺平道路。
