In a conventional field effect transistor device, the gate voltage induced electric field across the dielectric layer controls the conductivity of the channel between source and drain. In case an excitation in forms of heat, light, and magnetic field is able to significantly modulate the conductivity of the channel material controllably, a transistor gated thermally, optically, and magnetically can be rationally proposed and designed. Phase change materials provide a suitable platform for the study of the abovementioned devices.
A prototype “thermally” gated transistor is proposed, designed, fabricated, and characterized. A vanadium dioxide nanowire was employed as the channel of the transistor. Multiple Ti micro-heaters were fabricated around the nanowires as multi-gate structure with various gating capabilities. The transport properties of the “thermal” transistors were measured under various “thermal” gating powers and at different temperatures. The results were compared to the Id-Vd and Id-Vg characteristics of regular electrically-gated field effect transistors. This work is important for fundamental research as well as potential applications in specific areas.
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