Facile Fabrication of Highly-Stable and Wavelength-Tunable Tin based Perovskite Materials with Enhanced Quantum Yield via Cation Transformation Reaction
Jia-Ming Meng,1# Zhi-Xian Yang,1# Shivaraj B. Patil,1# Jou-Chun Lin,1# Chen-Hao Yeh,2 Yi-Chia Chen,1 Chih-Wen Pao,3 Jeng-Lung Chen,3 Wun-Yu Chen,4 Chin-Wei Lu,4 Tsung-Rong Kuo,5 Di-Yan Wang1*
just accepted by J. Phys. Chem. Lett.
Metal halide perovskites have attracted great attention for their superior light energy conversion applications. Herein, we demonstrated a facile synthesis of zero-dimensional Sn2+ perovskite Cs4-xMxSnBr6 (M= K+ and Rb+) material through cation transformation reaction at room temperature. Cs4SnBr6 NCs were mixed with pure metal bromide salts (KBr and RbBr) via mechanochemical process to successfully synthesize Cs4-xMxSnBr6 perovskite where transformation of Cs to mixed Cs/Rb and mixed Cs/K was achieved. By substituting different cations, the bright fluorescence of the Cs4-xMxSnBr6 was tuned from dim green to greenish-cyan while achieving the photoluminescence (PL) quantum yield of ~39 %. The crystal structure of Sn based perovskite with the substitution of K+ or Rb+ cations were determined by X-ray diffraction (XRD). Moreover, the Cs4-xMxSnBr6 demonstrated superior air-stability and exhibited a better photocatalytic activity for CO2 reduction reaction (CO2RR) with high selectivity of CH4 gas with higher yield rate compared to the pristine Cs4SnBr6 NCs.