Thermopower detection of single nanowire using a MEMS device

摘要

We present a MEMS-based device on a silicon nitride membrane in order to measure the thermoelectric properties of a single nanowire. A temperature gradient along a nanowire was generated by a nanoheater, and the temperature was measured by Pt thermometers. A thermal simulation using a finite element method was conducted to analyze the temperature distribution over the MEMS device. The validity of the MEMS device was established by testing the Pt nanowires which had different symmetry configurations. From the test results of Pt nanowires, a convincing temperature calibration method was proposed and applied to an actual case of Bi_2Te_3 nanowire. We measured a Seebeck coefficient of -53 μV/K and electrical conductivity of 2.23 × 10~5 S/m for a single Bi_2Te_3 nanowire with a diameter of 70 nm at 300 K. Our solid design for thermoelectric measurements based on a membrane structure enables the fast and high-yield characterization of one-dimensional nanostructures.