Experimental survey of dopants in Zn13Sb10 thermoelectric material

This work explores a variety of dopant incorporations into the Zn13Sb10 thermoelectric material synthesized from the stoichiometric composition by slow cooling. The experimental results revealed the preference for dopant atoms that can adopt a tetrahedral coordination environment of the Zn site. Incorporations of the dopants restrict the movement of Zn atoms, as evident from the suppressed α/α’ – β phase transitions. Incorporations affect both the electrical and thermal transport properties of the material, with outcomes being specific to the dopant. For instance, doping with Ga and In (both in group 13) affects the charge carrier concentration in a different way. Also, depending on the dopants, the dominant phonon scattering pathway can either be preserved (as the Umklapp scattering) or switched to a less effective point defect scattering. The origin of the Zn deficiency in Zn13Sb10 is not electronic in nature, but thermodynamic instead.