Direct measurement of thin-film thermoelectric figure of merit

We utilize the transient Harman technique to measure the thermoelectric figure of merit of thin films. A device structure is designed and fabricated to extract the thermoelectric properties of 20 mu m thick film composed of InGaAlAs semiconductor with embedded ErAs nanoparticles. High-speed voltage measurements with 63 dB of dynamic range and 200 ns resolution are achieved. Surface temperature measurements of the devices are used to extract the cross-plane Seebeck coefficient and thermal conductivity of the thermoelectric material. Self-consistent finite-element simulations of the three-dimensional temperature distributions in the active devices are in close agreement with the experimental thermal maps.