Analysis of ionic defect distribution on perovskite photodetector by temperature-dependent deep level transient spectroscopy

The High-efficiency Organohalide perovskites solar cells are produced via a solution-based method. Thus, a lot of defects are inevitable generated during fabrication processes, which are the main factors that affect the efficiency and long-term stability. The defect has been linked to the observation of reduce device stability against degradation and it can also create mid-gap states in a band structure as well act as recombination centers. Although the efficiency of the perovskite solar cells (PSCs) has been improved by curing defects using various passivation methods, deeply trapped defects in the perovskite layer have not been systematically studied, and their function is still unclear. In this study, we perform temperature-dependent deep-level transient spectroscopy (T-DLTS) measurements on PSCs, ionic defect parameters (activation energy, trap density, diffusion constants) for each observed ionic species were compared in different PSCs.