Thermal degradation of CH3NH3PbI3 perovskite into NH3 and CH3I gases observed by coupled thermogravimetry - mass spectrometry analysis

Energy Environ. Sci. 2016, 9, 3406-3410

Thermal gravimetric and differential thermal analysis (TG-DTA)
coupled with quadrupole mass spectrometry (MS) and first principles
calculations were employed to elucidate the chemical nature of
released gases during the thermal decomposition of CH3NH3PbI3. In
contrast to the common wisdom that CH3NH3PbI3 is decomposed
into CH3NH2 and HI, the major gases were methyliodide (CH3I) and
ammonia (NH3). We anticipate that our findings will provide new
insights into further formulations of the perovskite active material
and device design that can prevent methylammonium decomposition
and thus increase the long-term stability of perovskite-based opto-
electronic devices.