Si/SiGe nanoscale engineered thermoelectric materials for energy harvesting

Thermoelectric materials are one potential technology that could be used for energy harvesting. Here we report results from nanoscale Ge/SiGe heterostructure materials grown on Si substrates designed to enhance the thermoelectric performance at room temperature. The materials and devices are aimed at integrated energy harvesters for autonomous sensing applications. We report Seebeck coefficients up to 279.5±1.2 μV/K at room temperature with electrical conductivites of 77,200 S/m which produce a high power factor of 6.02±0.05 mWm^-1K^-2. Methods for microfabricating modules will be described along with techniques for accurate measurements of the electrical conductivity, Seebeck coefficient and thermal conductivity in micro- and nano-scale devices. The present thermoelectric performance is limited by a high threading dislocation density.