Structural Properties of Heavily B-Doped SiGe Thin Films for High Thermoelectric Power

Abstract

Heavily B-doped SiGe thin films was reported to have large thermoelectric power and power factor at room temperature after annealing. In this paper, we investigated the structures that give rise to the large thermoelectric power and power factor. The thin films were prepared by ionbeam sputtering method. The annealing temperature dependence of structural properties was investigated. The thin films exhibited large thermoelectric power (1.4 mVK � 1 ) and power factor (6:8 � 10 � 3 Wm � 1 K � 2 ) at room temperature after annealing at around 900 K. At that region, crystallite diameter was below 10 nm. The structure changed from amorphous to microcrystalline over 900 K. It is considered that quantum size effect enhances the thermoelectric power and power factor. [doi:10.2320/matertrans.E-M2010806]