Field-effect-dependent thermoelectric power in highly resistive Sb2Se3 single nanowire

Abstract

In this paper, we report the results of our experiments on and measurements of electrical resistivity and thermoelectric power (Seebeck coefficient) from single-crystalline antimony triselenide (Sb2Se3) single nanowires (NWs) with high resistivity (sigma similar to 4.37 x 10(-4) S/m). A positive Seebeck coefficient of approximately 661 mu V/K at room temperature was obtained using a custom-made thermoelectric power probe with an alternating current lock-in method (the 2 omega technique), which indicates that the thermal transport is dominated by holes. The measured Seebeck coefficient of the NWs is a factor of 2-3 lower than their bulk counterparts and is comparable to that of a highly conductive Sb2Se3 single NWs (approximately -750 mu V/K). We observed an increase in the Seebeck coefficients with increased bias voltages by field-effect gating, which cannot be explained by the modulation of the Fermi level in the NWs.