ИСТИНА

The discovery of a family of semiconductor materials based on the complex halides of group 14 elements opened a big research arena and led to the emergence of a new perovskite photovoltaic technology. Impressive photovoltaic performances were demonstrated for perovskite solar cells based on lead halides, whereas their practical implementation is still severely impeded by the low device operational stability. Most importantly, complex lead halides were found sensitive to both light and heat, which are unavoidable satellites under the realistic solar cell operational conditions. Suppressing these intrinsic degradation pathways requires a thorough understanding of their mechanistic aspects. Herein, we explored the temperature effects in the light-induced decomposition of the model systems represented by MAPbI3 and PbI2 thin films under well-controlled anoxic conditions. We show that decreasing the sample temperature from 55 oC to 30 oC can extend the perovskite lifetime spectacularly by a factor of >10-100 and also alter the material decomposition pathway. The analysis of the aging kinetics revealed that MAPbI3 and PbI2 photolysis have quite high effective activation energies of ~85 and ~106 kJ mol-1, respectively, which explain the observed strong effect of the temperature on the rate of the material photodecomposition. These findings suggest that controlling the temperature of the perovskite solar panels might be a key factor for reaching their long operational lifetimes (>20 years) required for the practical implementation of this promising technology.