Low-Cost Nanostructured Thermoelectric Materials for Efficient Power Generation at Low Temperature

Electricity generation processes burn fossil fuels, generating heat that is then used to produce power in a series of efficiency-robbing mechanical steps. These processes are able to generate a large amount of power, but waste a staggering 50 to 60% of the available heat energy due to technology limitations. Thermoelectric (TE) materials provide an attractive approach for recovering such waste heat and converting it to electric power. While much attention has been paid to the development of TE materials for high-temperature industrial heat generation, there has been less attention paid to effective energy scavenging of low-temperature waste heat (e.g. & lt;130 C) from sources such as household appliances such as hot water heaters, and smaller-scale industrial processes. Existing bulk fabrication methods (extrusion and dicing) as well as traditional microfabrication methods (sputtering and etching) cannot create structures with the correct size factors and aspect ratios for optimal power generation for these applications. Widespread use of low-temperature TE materials requires device efficiency improvements, manufacturing methods, and cost reductions in order to make energy harvesting practical. High-efficiency TE modules for solid-state energy conversion requires the development of TE semiconductors with a high figure of merit. To address this need, nanostructured BiSbTe materials will be demonstrated with record performance and manufactured using low-cost methods. Engineered via nanocrystal size, shape, boundary, and density of states, and doping, the p-type and n-type TE materials conduction-electron and photon scattering properties will be modulated so that good power generating efficiency can be achieved. Commercial Applications and Other Benefits: The potential for the microfabrication of thermoelectric power generators with efficient operation at low temperatures includes harvesting energy from ordinary heat-producing appliances such as hot water heaters, appliances, and photovoltaics as well as wearable electronics, cell phones, and mobile computers. Other applications include biomedical devices, where both on-skin and sub-dermal applications can be considered.