Temperature and spectral dependence of CH₃NH₃PbI₃ films photoconductivity

Halide perovskites are widely studied due to their potential applications in solar cells. Despite the remarkable success in increasing perovskite solar cell efficiency, the underlying photophysical processes remain unclear. To cover this gap, we studied temperature, spectral, and light intensity dependence of photoconductivity of CH₃NH₃PbI₃ films in the planar contact configuration. We observed non-monotonic behavior of the photoconductivity temperature dependence: a power-law decrease with increasing temperature at the temperatures below 185 K and close to exponential growth above this temperature. Spectral and light intensity dependences of photoconductivity allowed us to postulate that phase transition between tetragonal and orthorhombic structures and a change in the recombination channel are unlikely to be the reasons for abrupt change in photoconductivity behavior. Charge carrier mobility is proposed to be responsible for unusual photoconductivity changes with temperature.