Solar energy conversion into electricity and hot water by thermoelectric effect

Traditional utilization of solar energy is either to get electricity by photovoltaic effect (PV) or hot water by solar thermal absorption (SHW). For PV, the challenge was to reduce the cost, whereas for SHW the challenge was to increase the value of the thermal energy. Thermoelectric effect has a huge potential on converting the solar energy into electricity and hot water simultaneously at an acceptable cost. The performance of thermoelectric materials/devices depends on the thermoelectric figure-of-merit (ZT). Nanostructures have been demonstrated to be effective to reduce the thermal conductivity by stronger phonon scattering and eventually to enhance ZT. Materials that can be utilized at temperatures higher than 300 C is desired for power generation from heat sources such as car exhaust pipes, concentrated solar, etc. In this talk, I will discuss our recent studies on a few materials systems such as half-Heuslers, lead selenide, skutterudites, silicon-germanium alloys, etc. that are interest for power conversion applications including solar and any other heat sources.