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. © 1980-2012 IEEE.