By doping a thermoelectric material with minute amounts of sulfur, a team of researchers has found a new path to large improvements in the efficiency of materials for solid-state heating and cooling and waste energy recapture. This approach profoundly alters the electronic band structure of the material -- bismuth telluride selenide -- improving the so-called "figure of merit," a ranking of a material's performance that determines efficiency in applications and opening the door to advanced applications of thermoelectric materials to harvest waste heat from power plants to computer chips. http://news.rpi.edu/content/2016/06/16/new-approach-building-efficient-thermoelectric-nanomaterials