Methylammonium lead bromide (MAPbBr3), which belongs to the larger material family of lead halide perovskites (LHPs), has emerged as a promising semiconductor for the fabrication of single-crystal (SC)-based photodetectors (PDs). However, there is still a lack of sufficient understanding of the effect of irradiation power and applied temperature on the photodetection performance of SC-based perovskite PDs. Here, we investigate the impact of different light intensities and temperatures on the photodetection properties of planar-type MAPbBr3 SC-based PD with the help of transient photoresponse and impedance spectroscopy. The light intensity-dependent study revealed that the key performance parameters of PD decrease with increasing irradiation intensity due to changes in charge recombination and carrier lifetime. On the other hand, the detrimental effect of increasing temperature on the performance of PD was found to be related to the ion accumulation, increasing scattering of impurities and phonons, and change in conductivity and band gap rather than the change in charge recombination. This study provides a thorough understanding of the origin of light intensity and temperature-dependent photodetection properties of SC-based PD, which is crucial for the further advancement of optoelectronic devices based on LHPs.

Transient photocurrent is a widely applied characterization technique to probe the charge‐carrier photogeneration and extraction dynamics in perovskite optoelectronic devices. Despite the large number of studies on the properties of perovskite single‐crystals (SCs) photodetectors (PDs), the underlying mechanism that governs the spectral line shape of transient photocurrent is not fully understood. Here, methylammonium lead bromide (MAPbBr3)SC based PDs are used to study the effect of different electrode spacing and bias on the transient photocurrent response under blue and green light irradiation. The observed differences in the spectral line shape of the transient photocurrent are explained using three‐step carrier transport model, which reveals the occurrence of carrier trapping and a recombination process in MAPbBr3 SC. The findings are further corroborated by intensity‐dependent photocurrent and impedance spectroscopy analysis of the resulting PDs. This work provides a basic insight into the origin of the different behavior of transient photocurrent response under variable electrode distance, bias, and irradiance light, which is expected to help to further understand and optimize the performance of perovskite based PDs.