Highly Stable and Moisture-Immune Monocomponent White Perovskite Phosphor by Trifluoromethyl (-CF<sub>3</sub>) Regulation
Weihui Bi, Zisheng Wang, Hanming Li, Yilong Song, Xiaoting Liu, Yingqi Wang, Chengda Ge, Anran Wang, Yifei Kang, Yang Yang, Bao Li, Qingfeng Dong
Abstract
Halide perovskites are emerging as promising candidates for white light solid state lighting. Nevertheless, there are still challenges of a high water stability, a tunable color temperature, and a high photoluminescence quantum yield (PLQY). Herein, we report hydrophobic, electron-withdrawing trifluoromethyl (-CF3)-modified phenethylamine lead bromide (PEA2PbBr4) with ultrahigh stability in water for >2 months, and the broadband white light emission is illustrated by self-trapped excitons attributed to exciton–phonon coupling that coordinate molecular vibration, lattice distortion, and electrostatic interaction. In particular, by Mn2+ doping, the emission color can be tuned from cold (10237 K) to warm (2406 K), and a greatly enhanced PLQY of ≤87.93% can be achieved. Furthermore, the perovskites also possess an excellent color rendering index (the highest is 94). A monocomponent white light-emitting diode with amazing CIE 1931 coordinates of (0.33, 0.32) is further assembled, demonstrating a luminance of 471.5 cd m–2 at 50 mA and good long-term operation stability after >2 months. This study of highly efficient and stable perovskites with high-quality white light emission will open up new opportunities in solid state lighting.