The influence of electrode topology on the electrical and photoelectric characteristics of metal/semiconductor/metal structures was investigated. Gallium oxide films were obtained by radio-frequency sputtering of a Ga2O3 target onto sapphire substrates with the (0001) orientation. Two types of electrodes were formed on the surface of the oxide films: two parallel electrodes with an interelectrode distance of 250 mkm and interdigitated ones. The distance between the "fingers" of the detectors of the second type was 50, 30, 10, and 5 mkm. Regardless of the type of contacts, the structures exhibit sensitivity to ultraviolet radiation with a wavelength of λ = 254 nm. Detectors of the second type with an interelectrode distance of 5 μm demonstrate the highest values of the photocurrent Iph = 3.8 mA and detectivity D * = 5.54⋅10^15 cmHz^0.5W^-1.

The influence of ultraviolet radiation and a strong electric field on the current-voltage characteristic of resistive structures based on polymorphic films of gallium oxide is studied. Both types of Ga2O3 films were obtained by the method of chloride vapor-phase epitaxy on smooth and structured sapphire substrates with orientation (0001). In the same process α-Ga2O3 films were deposited on smooth substrates, and gallium oxide films, with regular structures perpendicular to the substrate, containing alternating regions of the α- and ε-phases were deposited on patterned substrate. It’s was observed, that radiation with λ = 254 nm and strong electric transfer structures from a state with low resistance to a state with high resistance. The response time to UV radiation is 5 seconds, and the recovery time less than 1 s.