An Amorphous (Al_0.12Ga_0.88)₂O₃ Deep Ultraviolet Photodetector

Abstract

The authors report the deposition of an (Al_xGa_1-x)₂O₃ amorphous thin film on sapphire substrates by sputter deposition. An amorphous deep ultraviolet (UV) (Al_0.12Ga_0.88)₂O₃ photodetector, with a cutoff wavelength at 230 nm, was also fabricated. With −10 V applied bias, it was found the dark leakage current and the linear dynamic range (LDR) of the fabricated photodetector were about 1.23 × 10⁻⁹ A and 59.51 dB, respectively. With the same −10 V applied bias, the UVC/UVA contrast ratio was larger than 20. With λ_illumination = 230 nm and −5 V applied bias, it was found noise equivalent power (NEP) and detectivity (D^*) of the fabricated amorphous deep UV (Al_0.12Ga_0.88)₂O₃ photodetector were 9.94 × 10⁻¹¹ W and 2.11 × 10¹⁰ cmHz^1/2W⁻¹, respectively. These results suggest the fabricated amorphous deep UV (Al_0.12Ga_0.88)₂O₃ photodetector herein indicate a cost-effective solution for developing DUV photodetector applications.