Influence of the Design of UV Radiation Detectors on Photoelectrical Characteristics

The results of the electrical and photoelectric characteristics of UV detectors based on Ga
2
O
3
thin films are presented. The paper considers detectors of several types: MSM-Ga
2
O
3
/ Al
2
O
3
structure with two parallel electrodes, MSM-Ga
2
O
3
/ Al
2
O
3
structure with interdigitated electrodes, and M/Ga
2
O
3
/n-GaAs vertical heterostructure. The gallium oxide film was deposited by RF-magnetron sputtering of the Ga
2
O
3
target (99.999%) on sapphire (0001) and GaAs (100) substrates, and thickness of the oxide film was 150–200 nm. The oxide film was annealed in Ar at 900°C for 30 minutes after depositing. Detectors of all types demonstrate sensitivity to irradiation with λ = 254 nm. The interdigital topology of the electrodes increases sensitivity to UV radiation. Structures based on M/Ga
2
O
3
/GaAs capable of operating in photovoltaic mode. The photoelectric characteristics of the heterostructure under UV irradiation with a wavelength of 254 nm at 0 V are: R = 200 mA/cm
²
and D* = 1 × 10
¹¹
cmHz
^0.5
W
^−l
.