Thickness Tuning Photoelectric Properties of β-Ga2O3 Thin Film Based Photodetectors

beta-Ga2O3 thin films were deposited on c-plane sapphire substrates by radio frequency magnetron sputtering technology. X-ray diffraction (XRD) results showed that the deposited beta-Ga2O3 films were oriented at ((2) over bar 01) direction. As beta-Ga2O3 thin film thickness increases, the grain size increases accordingly. Metal/semiconductor/metal structured UV PDs based on various thickness beta-Ga2O3 thin films have been fabricated. The optical and electrical properties of beta-Ga2O3 thin films are thickness dependent, such as absorption peak blue shift, band gap red shift and lower dark current. Moreover, it was found that the thickness of about 200 nm for the beta-Ga2O3 film based photodetector exhibit higher photoresponse, faster rise time and fall time.