Measuring Thermal Processes of Methylammonium Lead Iodide (CH$_{\mathrm{3}}$NH$_{\mathrm{3}}$PbI$_{\mathrm{3}})$ Perovskite

Perovskites have~recently been the focus of much research due to their performance as a photosensitizers for solar energy conversion applications. We have explored the thermal properties of this material, focusing on the role~of the cation methylammonium within the perovskite lattice.~Temperature-dependent thermal conductivity of the perovskite in~the range between 7K and 300K was compared to the cesium perovskite analog, and the data were~fitted to a Debye model, revealing the effect of the methylammonium component on~phonon scattering and a source of increased thermal resistance. Thermal conductivity was also measured for naturally aged perovskite samples,~showing that the degradation product's thermal behavior approaches that of lead iodide, one of~the thermodynamic end products. Our results~highlight the effectiveness of thermal transport measurements for analyzing material integrity of perovskite-based devices.