Scientists at Lawrence Berkeley National Laboratory (Berkeley Lab) have constructed a low-cost, nanoscale composite hybrid thermoelectric material by wrapping a polymer that conducts electricity around a nanorod of tellurium—a metal coupled with cadmium in today’s most cost-effective solar cells.
(Thermoelectric (TE) devices produce a voltage potential as a byproduct of a difference in temperature; that potential can then be used to drive an electrical current. Such devices can recover some of the energy embedded in waste heat, such as that produced by the exhaust gas of an IC engine. (Earlier post.) A number of automakers are exploring the potential for thermoelectric generators (TEGs) for waste heat recovery.)
The composite material is easily spin cast or printed into a film from a water-based solution. Along with its ease of manufacture, this hybrid material also has a thermoelectric figure of merit (room temperature ZT ~0.1) thousands of times greater than either the polymer or nanorod alone—a crucial factor in boosting device performance.
Historically, high-efficiency thermoelectrics have required high-cost, materials-intensive processing. By engineering a hybrid of soft and hard materials using straightforward flask chemistry in water, we’ve developed a route that provides respectable efficiency with a low cost to production.—Jeff Urban, Deputy Director of the Inorganic Nanostructures Facility at the Molecular Foundry
A paper on the research was published in the ACS journal Nano Letters.
The Molecular Foundry is one of the five DOE Nanoscale Science Research Centers (NSRCs), national user facilities for interdisciplinary research at the nanoscale, supported by the DOE Office of Science. Together the NSRCs comprise a suite of complementary facilities that provide researchers with state-of-the-art capabilities to fabricate, process, characterize and model nanoscale materials, and constitute the largest infrastructure investment of the National Nanotechnology Initiative.
The NSRCs are located at DOE’s Argonne, Brookhaven, Lawrence Berkeley, Oak Ridge and Sandia and Los Alamos National Laboratories.
Kevin C. See, Joseph P. Feser, Cynthia E. Chen, Arun Majumdar, Jeffrey J. Urban, and Rachel A. Segalman (2010) Water-Processable Polymer-Nanocrystal Hybrids for Thermoelectrics. Nano Lett., Article ASAP doi: 10.1021/nl102880k