ИСТИНА

Here we studied the degradation processes of tin halide perovskites (tin(II)- cesium iodide and tin(II)-methylammonium iodide) obtained from the solutions in water or propanol-2 by heating in open air or long-term drying in inert atmosphere. These compounds were subjected to X-ray diffraction analysis right after crystallization and their degradation during one month of staying in open air. The same analysis was made with the tin(IV)-cesium iodide. Additionally, the absorption spectra of tin(II)-methylammonium iodide, tin(II)-cesium iodide and tin(IV)-cesium iodide samples right after synthesis and after few days of staying in open air are studied. Degradation of tin(II)-methylammonium iodide and tin(II)-cesium iodide after a one week of staying under high temperature (about 40 o C) or high moisture (above 60% compared to 20% in previous study) was analyzed in a same way.