The structural, optical and electrical properties of a-SiGe:H:F alloys from $SiH_2F_2/GeH_4(/H_2)$, and a-SiGe:H alloys from $SiH_4/GeH_4(/H_2)$ prepared by glow discharge deposition are discribed. These properties are examined by dark- and photo-conductivity, photoluminesence, IR absorption spectra, scanning electron microscopy and the effect of $H_2$ dilution ar observed also.
For the a-SiGe:H:F alloys which have poor material quality photo-electrical properties and heterogeniety are improved with optical gap change by $H_2$ dilution, but for the a-SiGe:H alloys heterogeniety is improved without photo-electrical properties change abruptly.
