Effect of Ultraviolet Radiation and Electric Field on the Conductivity of Structures Based on [alpha]- and [epsilon]-Ga.sub.2O.sub.3

The effect of ultraviolet radiation and a strong electric field on the conductivity of structures based on two types of polymorphic gallium-oxide films is studied. Both types of Ga.sub.2O.sub.3 films are obtained by hydride vapor phase epitaxy on smooth and patterned sapphire substrates with the orientation (0001). In one and the same process, on smooth substrates, [alpha]-Ga.sub.2O.sub.3 films are obtained and, on patterned substrates, gallium-oxide films with regular structures perpendicular to the substrate containing alternating regions of [alpha]- and [epsilon]-phases are deposited. Resistive structures based on two-phase films exhibit a transition from a state with low resistance to a state with high resistance under the action of radiation with [lambda] = 254 nm and a strong electric field. The time of response to UV radiation is 5 s, and the recovery time is shorter than 1 s.