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

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 (σ ~ 4.37 × 10⁻⁴ S/m). A positive Seebeck coefficient of approximately 661 µV/K at room temperature was obtained using a custom-made thermoelectric power probe with an alternating current lock-in method (the 2ω 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 µV/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.