The reasons for the improvement of the properties of a-SiGe:H when using hydrogen diluted gas mixtures are reappraised and it is suggested that reduction of the contribution of short-lifetime-radicals to film-growth is the responsible cause. Using disilane-germane gas mixtures, very low power density and reasonably high pressure, the preferential depletion of germane to prepare material which is comparable to that prepared using hydrogen-diluted silane-germane gas mixtures has been avoided.
Ganguly, G., & Matsuda, A. (1996). Role of hydrogen dilution in improvement of a-SiGe:H alloys. Journal of Non-Crystalline Solids, 198–200(PART 1), 559–562. https://doi.org/10.1016/0022-3093(95)00763-6