BiFeO3/CH3NH3PbI3 Perovskite Heterojunction Based Near-Infrared Photodetector

Abstract

The Letter reports a hybrid (i.e. organic-inorganic) perovskite CH3NH3PbI3 and inorganic only perovskite BiFeO3 based heterojunction diode for near-infrared detection applications. The hybrid halide CH3NH3PbI3 is synthesized by using sol-gel chemical route while the BiFeO3 is synthesized by using a solid-state route. A layer of uniformly distributed BiFeO3 thin film is first grown on an indium doped tin oxide (ITO) coated glass substrate using BiFeO3 nanoparticles with an average size of ~65 nm. Then, CH3NH3PbI3 nanoparticles of average size ~45 nm with a tetragonal phase are deposited BiFeO3 film for fabricating the heterojunction device under study. The photoresponse is measured by using a monochromatic light over the wavelengths from 400 to 900 nm. The device shows a dual-band photoresponsivity originated from the individual absorption characteristics of BiFeO3 and CH3NH3PbI3 perovskites used for the heterojunction. The proposed photodetector shows the maximum responsivity of ~2 A/W at 800 nm for 2 V bias while the detectivity is estimated as $\sim {7.8}\times {10}^{{12}}$ cmHz1/2/W. The photodetector has a reasonably good photoresponse with a rise time and fall time of 0.74 s and 0.088 s, respectively.