Opaque-Gate Phototransistors on H-Terminated Diamond

Abstract

Opaque-gate ultraviolet sensitive transistors were fabricated on H-terminated polycrystalline diamond. Butterfly shaped structures with different geometric ratios were realized. Observed trends with the gate unbiased demonstrated behavior as p-channel normally-off transistors, switched-on by the impinging UV light. Linearity with the UV beam power was also observed with over-gap radiation. Under steady state illumination, a linear increase of the photocurrent was found when the gate is biased at different voltages in the saturation regime. The operative generation-charge transport mechanism of fabricated devices is discussed.