An Amorphous (Al0.12Ga0.88)2O3 Deep Ultraviolet Photodetector

The authors report the deposition of an (Al
_x
Ga
_1-x
)
₂
O
₃
amorphous thin film on sapphire substrates by sputter deposition. An amorphous deep ultraviolet (UV) (Al
_0.12
Ga
_0.88
)
₂
O
₃
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
_0.12
Ga
_0.88
)
₂
O
₃
photodetector were 9.94 × 10
⁻¹¹
W and 2.11 × 10
¹⁰
cmHz
^1/2
W
⁻¹
, respectively. These results suggest the fabricated amorphous deep UV (Al
_0.12
Ga
_0.88
)
₂
O
₃
photodetector herein indicate a cost-effective solution for developing DUV photodetector applications.