SiGe alloy film with very high electrical conductivity and thermoelectric power

Abstract

Heavily doped SiGe alloy film prepared by glow discharge decomposition has been investigated by measuring both electrical conductivity and thermoelectric power. It has been found that their electrical conductivity increases suddenly with transition from the amorphous state to the microcrystalline state (up to 250 s·cm −1), and that their thermoelectric power has an extremely large Seebeck coefficient of 160 μV/K. An examination of both X-ray diffraction and Raman scattering shows that the film is composed of the random mixing of SiSi, SiGe and GeGe bonds and volume fractions of crystallinity are estimated from 30% to 90% for highly conductive SiGe alloy film.