Experimental Demonstration of Correlated Flux Scaling in Photoconductivity and Photoluminescence of Lead-Halide Perovskites

Despite the rapid progress in lead-halide perovskite solar cells, our understanding of the basic optoelectronic properties of these materials is still incomplete. Here the authors show a clear, universal correlation between the photoexcitation-flux dependences of photoconductivity and photoluminescence, which helps to uncover the unique photophysics of these materials. While the photoconductivity exhibits a crossover in its power law from an exponent of 1 to \textonehalf{}, the photoluminescence crosses from 2 to 1\textonehalf{}. The authors discuss phenomenological scenarios leading to this unusual situation, and propose an analytical model of competing carrier diffusion and recombination.