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Structural, Optical, and Thermal Properties of Cs 2 SnI 6 – x Br x Mixed Perovskite Solid Solutions
Author(s) -
Yuan Guan,
Huang Shengxuan,
Qin Shan,
Wu Xiang,
Ding Hongrui,
Lu Anhuai
Publication year - 2019
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201900120
Subject(s) - chemistry , solid solution , raman spectroscopy , rietveld refinement , thermogravimetric analysis , analytical chemistry (journal) , lattice constant , x ray crystallography , crystal structure , crystallography , thermal stability , lattice energy , diffraction , physics , organic chemistry , chromatography , optics
Cs 2 SnI 6‐ x Br x ( x = 0–6) solid solutions have been synthesized by chemical solid solution reaction in conjunction with sintering under vacuum. The Rietveld refinements of powder X‐ray diffraction (XRD) patterns indicate that all the samples are cubic, with a symmetry of Fm 3 m . The lattice parameter a decreases linearly as a function of the Br content in Cs 2 SnI 6‐ x Br x . Raman spectra suggest that the new Raman peaks might derive from the short‐range ordering of I/Br anions. The UV/Vis reflection spectra reveal a nonlinear trend of energy band gap (Eg) from 1.25 eV to 3.01 eV with increasing Br content. Hence the wide range of Eg of Cs 2 SnI 6‐ x Br x solid solutions are capable to overlay almost the entire visual spectrum. Thermogravimetric analysis (TGA) results suggest that the thermal stability of Cs 2 SnI 6‐ x Br x increases gradually with increasing Br content. Cs 2 SnI 6‐ x Br x with the fine thermal stability and tunable Eg indicate high potential in the applications of solar cell devices.