Thermoelectric properties of electrically stressed Sb/Bi-Sb-Te multilayered films

Electrically stressed Bi-Sb-Te thin films have demonstrated markedly enhanced Hall mobility and moderately reduced carrier concentration. To lower electrical resistivity further, a Sb-inserted Bi-Sb-Te multilayer structure was prepared through consecutively sputtering Bi-Sb-Te and Sb layers followed by electric current stressing. The electrically stressed Sb/Bi-Sb-Te film demonstrates high carrier concentration and enhanced Hall mobility. We propose that the additional Sb supply suppresses electromigration-induced Sb depletion in crystal lattices, thus maintains high carrier concentration of the Bi-Sb-Te film. The presented approach provides a simple means to optimize thermoelectric properties of Bi-Sb-Te films.