Long-Persistent Luminescence from Double Self-Defect States in Undoped Cs3In2Cl9 Nanocrystals for Bioimaging and Display Technologies
Shuang Yang, Wenhui Guo, Zhenyu Tang, Zehao Zhang, Haoqing Guo, Yinan Lao, Bo Qu, Lixin Xiao, Junjie Shi, Zhijian Chen
Abstract
A long-persistent luminescence (LPL) material based on lead-free perovskite nanocrystals (Cs3In2Cl9 NCs) was synthesized by hot injection at 175 °C. Based on X-ray diffraction and theoretical calculations, the crystal structure of Cs3In2Cl9 NCs belongs to the trigonal space group R3̅c. The Cs3In2Cl9 NC powder emits white light at a peak wavelength of 430 nm with a full width at half maximum (FWHM) of about 118 nm and a photoluminescence quantum yield (PLQY) of 26.3%. The lifetime of its LPL is ∼1 s at 300 K and ∼10 s at 77 K. To explain the mechanism of LPL in Cs3In2Cl9, double self-defect states (DSDS) were proposed. To the best of our knowledge, this is the first time to obtain LPL in undoped lead-free perovskites. It promotes the application of perovskites and the explanation of the mechanism of LPL.