Microcrystalline silicon germanium: an attractive bottom-cell material for thin-film silicon-based tandem-solar-cells

摘要

We have prepared hydrogenated microcrystalline silicon germanium by plasma enhanced CVD of a mixture of silane and germane gas diluted with hydrogen.The growth conditions have been systematically controlled to obtain large (approx 400A) crystallites of silicon-germanium as observed using Raman scatterin gand x-ray diffraction.The dangling bond (germanium) density has been reduced to < 5x10~16 cm~-3 at low substrate temperatures (approx 150 deg C).The optical absorption spectra of the 50