Dual‐Band‐Tunable White‐Light Emission from Bi<sup>3+</sup>/Te<sup>4+</sup> Emitters in Perovskite‐Derivative Cs<sub>2</sub>SnCl<sub>6</sub> Microcrystals
Wei Zhang, Wei Zheng, Lingyun Li, Ping Huang, Zhongliang Gong, Ziwei Zhou, Jinyue Sun, Yan Yu, Xueyuan Chen
Abstract
Abstract Luminescent metal halides have attracted considerable attention in next‐generation solid‐state lighting because of their superior optical properties and easy solution processibility. Herein, we report a new class of highly efficient and dual‐band‐tunable white‐light emitters based on Bi 3+ /Te 4+ co‐doped perovskite derivative Cs 2 SnCl 6 microcrystals. Owing to the strong electron‐phonon coupling and efficient energy transfer from Bi 3+ to Te 4+ , the microcrystals exhibited broad dual‐band white‐light emission originating from the inter‐configurational 3 P 0,1 → 1 S 0 transitions of Bi 3+ and Te 4+ , with good stability and a high photoluminescence (PL) quantum yield of up to 68.3 %. Specifically, a remarkable transition in Bi 3+ ‐PL lifetime from milliseconds at 10 K to microseconds at 300 K was observed, as solid evidence for the isolated Bi 3+ emission. These findings provide not only new insights into the excited‐state dynamics of Bi 3+ and Te 4+ in Cs 2 SnCl 6 , but also a general approach to achieve single‐composition white‐light emitters based on lead‐free metal halides through ns 2 ‐metal ion co‐doping.