Solar-Blind Photodetectors based on Ga_2O_3 and Ⅲ-Nitrides

摘要

Recently, there has been a surge of interest in the wide bandgap semiconductors for solar blind photo detectors (SBPD).This work presents our recent progress in the growth/doping of AlGaN and Ga_2O_3 thin films for solar blind detectionapplications. Both of these thin films grown are grown by metal organic chemical vapor deposition (MOCVD) in thesame Aixtron MOCVD system. Solar-blind metal-semiconductor-metal photodetectors were fabricated with Ga_2O_3.Spectral responsivity studies of the MSM photodetectors revealed a peak at 261 nm and a maximum EQE of 41.7% for a?2.5 V bias. We have also demonstrated AlGaN based solar-blind avalanche photodiodes with a gain in excess of 57,000at ～100 volts of reverse bias. This gain can be attributed to avalanche multiplication of the photogenerated carrierswithin the device. Both of these devices show the potential of wide bandgap semiconductors for solar blind photodetectors.