Hydrogenated amorphous silicon germanium alloys thin films had been grown by PECVD method. This article shows characteristics of hydrogenated amorphous silicon germanium thin film solar cells with GeH4 flow rates. The optical bandgap of hydrogenated amorphous silicon germanium alloy decreased from 1.78 eV - 1.54 eV with increasing in GeH4 flow rate from 0 sccm - 100sccm. The various values of V-oc, J(sc), FF, and conversion efficiency were measured by the solar simulator. These results show that the conversion efficiency of the a-SiGe:H solar cells was very high when the GeH4 flow rate was 60 sccm.