Properties of resistive structures based on gallium oxide polymorphic phases

The effect of UV radiation and a strong electric field on the current–voltage characteristics of resistive structures based on polymorphic gallium oxide (Ga$_{2}$O$_{3}$) films is discussed. Ga$_{2}$O$_{3}$ films were deposited by the method of halide vapor phase epitaxy (HVPE) on smooth and patterned sapphire substrates with a baseline orientation (0001). $\alpha$-Ga$_{2}$O$_{3}$ films grow on smooth substrates, and gallium oxide films containing $\alpha$ and $\varepsilon$ phases grow on patterned ones. A switching effect was detected in the metal/Ga$_{2}$O$_{3}$/metal structures based on two-phase films. When exposed to radiation with $\lambda$ = 254 nm and a strong electric field, the structures pass from a low resistive state to a high resistive state.