ICT2014 Abstracts

As the renewable energy movement continues to gather momentum, the thermoelectric community is enjoying increased involvement in the energy community. Renewed motivation for the development of solar thermoelectric generator (STEG) modules, and the continued commercialization of thermoelectric technology continues to increase demand for new materials. However, many thermoelectrics are comprised either of toxic or rare materials. PbTe, for example, possesses exceptional characteristics for a thermoelectric material: high band degeneracy, fortuitously positioned conduction band minima, and an exceptional figure of merit (zT > 2.2). However, PbTe is often scrutinized for its reliance on lead and tellurium. As societal pressures push for environmentally benign solutions, the demand for Earth-abundant, non-toxic thermoelectric materials continues to grow. There is reason to believe that other binary rock-salt compounds may be able to mimic the electronic properties of PbTe while incorporating Earth-abundant, non-toxic elements. Utilizing NREL's high-throughput computational tools, we have identified several material systems of interest. Among these is rock-salt SnS, an allotrope of the room temperature phase which has long been studied for photovoltaic applications. Experimental verification, guided by computation is used to develop SnS specifically for thermoelectric applications. Here we investigate routes to stabilize the rock-salt structure through a combination of computation and bulk synthesis. Drawing inspiration from similar work on CdS, alloying with alkali-earth sulfides is employed. Effects of alloying on the thermoelectric properties of rock salt SnS are examined.