The search for thermoelectrics, exotic materials that convert heat directly into electricity, has received a boost from researchers at the California Institute of Technology and the University of Tokyo, who have found the best way to identify them.
In the new open-access journal APL Materials, the team shows that a relatively simple technique called the “rigid band approximation” can predict a material’s properties more accurately than a competing, more complicated method.
“The rigid band approach still supplies the simple, predictive engineering concepts we need for discovering fruitful thermoelectric material compositions,” says G. Jeffrey Snyder, a Caltech faculty associate in materials science, who led the research.
Thermoelectrics have been used since the 1950s to power spacecraft by converting the heat from radioactive decay into electricity. Their unusual properties arise from complex interactions between the many electrons associated with the atoms in alloys of heavy metals such as lead, bismuth, tellurium and antimony.
With no moving parts, thermoelectric generators are quiet and extremely reliable, requiring minimal maintenance. However, the generators are relatively inefficient (typically less than 10 percent) and the materials needed to build them are expensive—factors that have prevented their widespread use and limited thermoelectrics to niche applications such as spacecraft or wine refrigerators.
Read more at: Phys.org