Enhancing bromine-doped CuBiI4 photodetectors through charge dynamics and conductivity analysis

Lead-free perovskite-like semiconductors exhibit promising optoelectronic properties for various applications, including signal detection. However, the photocurrent density in these materials is often constrained by limitations in photogenerated charge dynamics. In this study, we introduced bromine dopants into CuBiI4 crystalline films for the first time and observed a significant enhancement in photocurrent density, increasing by approximately 4.8 times compared to undoped CuBiI4. Through comprehensive investigations into band structures, charge separation, and recombination dynamics, we elucidated the mechanisms underlying this enhancement, which proved to have a profound impact on charge densities. Specifically, the internal generation of photocharge densities was found to be influenced by several factors.