Temperature-Dependent Thermal Decomposition Pathway of Organic–Inorganic Halide Perovskite Materials

The thermal decomposition products and kinetics of two typical organic–inorganic halide perovskites, CH3NH3PbI3 (MAPbI3) and HC(NH2)2PbI3 (FAPbI3), were investigated via simultaneous thermogravimetric analysis coupled with Fourier transform infrared spectroscopy. NH3 and CH3I were verified as the major thermal decomposition gases of MAPbI3. Furthermore, for the first time, methane (CH4) was observed as a thermal degradation product of MAPbI3 at elevated temperatures. In contrast to conventional wisdom, (HCN)3 (trimerized HCN) and NH3 were demonstrated as the major gaseous decomposition products of FAPbI3 at lower temperatures, while HCN and NH3 became dominant at high temperatures (>360 °C). The hybrid experimental/theoretical results presented in this study will further our understanding of the perovskite decomposition mechanism and provide new insights into designing of long-term stable perovskite-based devices.