Fig. 1. Material structure and characterization. (a) Schematic of epitaxial film structure; (b) surface topography measured by profilometry

Fig. 2. Photoelectric characteristics of the device under UV irradiation with an incident optical power of 100 μW/cm². (a) Dark current density and photocurrent density of SB-PIN and PIN photodetectors with 275 nm illumination; (b) dark current density and photocurrent density of SB-PIN photodetector with 365 nm illumination; (c) responsivity and detectivity of SB-PIN device with 275 nm illumination; (d) responsivity and detectivity of SB-PIN device with 365 nm illumination

Fig. 3. Responsivity changed with bias voltage and optical power density. (a) Responsivity changed with bias voltage under 275 nm illumination with different power densities; (b) responsivity changed with bias voltage under 365 nm illumination with different power densities; (c) responsivity changed with incident light power density at bias voltage of -10 V and +10 V under 275 nm illumination; (d) responsivity changed with incident light power density at bias voltage of +10 V under 365 nm illumination

Fig. 4. Temporal response test results of the photodetector . (a) Test results at the bias voltage of -10 V and +10 V under 275 nm illumination; (b) test result at the bias voltage of +10 V under 365 nm illumination

Fig. 5. Energy band diagrams and working principles of the device. (a) Under negative bias voltage; (b) under positive bias voltage