It also points out that the higher electricity generating efficiency and lower cost will be obtained if polycrystalline silicon germanium ( poly - sige ) alloys is used as solar energy materials compared with polycrystalline silicon thin film ( poly - si ) 文章阐明用多晶锗硅薄膜作为太阳能电池材料,能获得比多晶硅薄膜太阳能电池更高的发电效率和更低的成本。