Boosting Photocurrent via Heating BiFeO_3 Materials for Enhanced Self-Powered UV Photodetectors

摘要

BiFeO3 (BFO) is a potentially important Pb-free ferroelectric with a narrow bandgap and is expected to become a novel photodetector. The photocurrent in BFO3 strongly depends on the temperature but only a few studies have investigated in detail the relationships between photocurrent and temperature. Here, the temperature-dependent photocurrent and the corresponding photosensing properties of a Ag/BFO/indiumtin oxide (ITO) photodetector based on an optimized planar-structured electrode configuration are investigated. The photocurrent and responsivity of the BFO3-based photodetector can first be increased and then be decreased with increasing temperature. The largest photocurrent and responsivity can reach 51.5 mu A and 6.56 x 10(-4) A W-1 at 66.1 degrees C, which is enhanced 126.3% as compared with that at room temperature. This may be caused by the temperature-modulated bandgap and barrier height in Ag/BFO/ITO device. This study clarifies the relationship between photosensing performance and the operating temperature of BFO-based photodetector and will push forward the application of ferroelectric materials in photoelectric field.