Highly stable CsFAPbIBr perovskite solar cells with dominant bulk recombination at real operating temperatures

Mixed-cation mixed-halide perovskite solar cells have been characterized in DC at different temperatures (from -20 degrees C up to 50 degrees C) and the time evolution of the device efficiency has been assessed using different degradation protocols (indoors and outdoors). The completely planar p-i-n structure is ITO/CuNiOx/PTAA/CsFAPbIBr/PCBM/PEI/Ag. Pristine current-voltage characteristics barely show hysteresis, at any temperature. Open circuit voltage decreases with temperature at a rate of -1.5 mV degrees C-1, and the obtained PCE temperature coefficient is lower than -0.001% K-1, which is an outstanding value for this emerging photovoltaic technology. Cells have been degraded under different protocols: indoors using different light/dark cycles and outdoors in a high temperature and high irradiation location. Cells show no significant decrease of the efficiency after more than 350 h of indoor light cycling and the estimated T-80 obtained for the sample degraded outdoors under high irradiation and high temperature conditions is similar to 15 days.

Automated summary

Mixed-cation mixed-halide perovskite solar cells were characterized in DC at various temperatures and their efficiency degradation was assessed using different degradation protocols. The cells demonstrated high stability with minimal efficiency decrease after extended indoor light cycling and a T-80 value of approximately 15 days under outdoor high temperature and high irradiation conditions.