High Gain β-Ga2O3 Solar-Blind Schottky Barrier Photodiodes via Carrier Multiplication Process

β-Ga 2 O 3 , which is a ultra-wide band-gap semiconductor, is an attractive material for next-generation solar-blind photodetectors.A high gain solar-blind Schottky barrier photodetector using an exfoliated single crystalline β-Ga 2 O 3 nano-layer was demonstrated by employing internal carrier multiplication process.Excellent spectral selectivity with high responsivity was obtained between UV-A and UV-C wavelengths with fast response/decay characteristics.The gain of our β-Ga 2 O 3 solar-blind PD was ∼3.78 × 10 3 under the multiplication mode at the reverse bias of -60 V, where the peak electric field was estimated to be 4.3 MV/cm (equivalent to impact ionization coefficient of 5 × 10 3 cm -1 ).Compared with non-multiplication mode, outstanding photo-sensing performances were achieved under the multiplication mode, including a responsivity of 8.18 A/W, a photocurrent-to-dark-current ratio of ∼10 3 and external quantum efficiency of ∼4 × 10 3 %.High gain via carrier multiplication process in a β-Ga 2 O 3 photodiode proposes a new route toward high performance solar-blind deep-UV photodetectors.