Doped all-inorganic cesium zirconium halide perovskites with high-efficiency and tunable emission

Doping enables manipulation of both the electrical and optical properties of halide perovskites. Herein, we incorporated Te4+ into Cs2ZrCl6 single crystal, simultaneously preserving the vacancy-ordered structure, to obtain an efficient yellow-emitting perovskite with a near-unity photoluminescence quantum yield (PLQY approximate to 97.6%). Te4+ doping modifies the hue and emission color of pristine Cs2ZrCl6, generates new absorption channels, and successfully extends the excitation energy from < 280 nm to 360-450 nm range. Detailed spectral characterizations, including ultrafast femtosecond transient absorption measurements, reveal that the bright yellow light is derived from triplet self-trapped excitons. Moreover, further tuning doping concentration enables Te-doped Cs2ZrCl6 single crystals to exhibit efficient warm white light emission. This work provides a new perspective for the development and design of stable lead-free perovskites with highly efficient luminescence. (C) 2021 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

Doping of Te4+ into Cs2ZrCl6 single crystal enables efficient yellow light emission with a near-unity photoluminescence quantum yield, while preserving the vacancy-ordered structure. The Te4+ doping modifies optical properties, generates new absorption channels, extends excitation energy range, and allows for tuning of doping concentration to exhibit warm white light emission.