Study of self-powered solar-blind deep UV photodetectors based on (InxGa1-x)2O3/Bi2Se3 heterojunction

β-Ga 2 O 3 has promising applications in solar-blind photodetectors due to its intrinsic bandgap. In this work, (In x Ga 1-x ) 2 O 3 thin films were deposited on c-plane sapphire substrates via molecular beam epitaxy (MBE). And a (In 0.1 Ga 0.9 ) 2 O 3 /Bi 2 Se 3 heterojunction photodetector was fabricated. The device demonstrates excellent performance under 254 nm illumination at zero bias, achieving a high responsivity of 353 mA/W, a detectivity of 9.5 × 10 11 Jones, and a rejection ratio (R peak /R 280 nm ) of 14. Furthermore, it exhibits a fast response speed with a rise time of 18 ms and a decay time of 26 ms, respectively. These excellent performances are owed to the high quality and type-I energy band alignment of the interface between (In 0.1 Ga 0.9 ) 2 O 3 and Bi 2 Se 3 thin films.