Obtaining and characterization of MAPbSnBr3 perovskite crystals trough AVC method

Abstract

The obtaining tin-based perovskite from solution is challenging due to the rapid and uncontrollable crystallization of tin compared to lead-based perovskite. Another challenge is to reduce the use of lead to avoid poisoning. In this sense, Sn-based perovskite compounds such as CsSnBr3 have attracted great attention as an effective replacement, but current photovoltaic devices still problems of low efficiency and instability chemistry. The band gap of ASnX3 compounds is between 1.2 and 1.4 eV, being the ideal range for maximum theoretical efficiency in a solar cell. In contrast, APbX3 compounds have band gaps in the range of 1.45 to 1.6 eV. We synthesize MAPbSnBr3 perovskite crystals through the AVC method. The structural properties of the crystals were obtained by X-ray diffraction, Raman spectroscopy, these shown the presence of Sn and Pb in the crystals obtained, and the optical properties by UV-Vis absorption and photoluminescence spectroscopy obtaining the variation of the band gap in the perovskite.The results obtained from the MAPbSnBr3 perovskite (such as the band gap, absorption spectrum and crystal lattice) meet the necessary requirements for its possible application in photovoltaic devices. It is shown that it is possible to obtain MAPbSnBr3 crystals with a lower amount of Pb and how the bandgap is affected by varying these elements, for their possible application in solar cells.