Substrate Bias Effect on SOI-based Thermoelectric Power Generator

Thermoelectric characteristics of phosphorus-doped silicon (Si) nanowire (NW) are evaluated in terms of the substrate bias effect. It is found that the narrower wire is more sensitive to the substrate voltage presumably due to the field crowding effect. In case of 200-nm-wide NW, application of 40 V to the substrate increases the NW conductance by a factor of 55.4, and leads to × 25.9 improvement in power generation, even though the Seebeck coefficient is reduced to 74%. The result suggests that the performance of the Si thermoelectric generator could be improved or optimized by the substrate bias control.