Thermoelectric materials offer the potential to harness electricity from otherwise wasted heat.
Continuing research in the field could yield applications scavenging energy from vehicle exhaust systems, industrial processes and equipment, and even sunlight. Now researchers have created a material with a higher energy conversion efficiency that could make such systems more feasible.
Researchers at Northwestern University created the new material by dispersing nanocrystals of rock salt (SrTe) into lead telluride (PbTe). While this kind of nanoscale inclusion in bulk material had previously been shown to improve the energy conversion efficiency of lead telluride, it also increased the scattering of electrons, which reduced the material’s overall conductivity. The Northwestern team’s study offers the first example of using nanostructures in lead telluride to reduce electron scattering and increase the energy conversion efficiency of the material. The researchers say the resultant material is expected to enable 14 percent of waste heat to electricity.
“It has been known for 100 years that semiconductors have this property that can harness electricity,” said Mercouri Kanatzidis, the Charles E. and Emma H. Morrison Professor of Chemistry in The Weinberg College of Arts and Sciences. “To make this an efficient process, all you need is the right material, and we have found a recipe or system to make this material.”