Ultrasensitive Perovskite Photodetectors by Co Partially Substituted Hybrid Perovskite

In the past nine years, hybrid perovskite materials have attracted extensive research interests in both academic and industrial sectors. In this work, we report ultrasensitive solution-processed perovskite photodetectors by novel perovskite materials, where lead (Pb2+) is partially substituted by cobalt (Co2+). The CH3NH3Pb0.9Co0.1I3 thin film exhibits a cubic crystal structure, optimal thin film morphology, balanced charge carrier mobilities, and suppressed defects compared to pristine CH3NH3PbI3 thin film with a tetragonal crystal structure, poor film morphology, and unbalanced charge carrier mobilities. As a result, perovskite photodetectors fabricated by the CH3NH3Pb0.9Co0.1I3 thin film exhibit detectivities approximatively 1013 Jones (1 Jones = 1 cm Hz1/2 W–1) in the spectra region from 350 to 800 nm at room temperature and over 100 dB linear dynamic range. All these results indicate that our findings of partial substitution of Pb2+ by Co2+ can tune materials’ physical properties and further boost the device performance of perovskite photodetectors.