Cast polycrystalline silicon solar cell with grooved surface

Improving the efficiency of polycrystalline silicon solar cells by using an efficient surface groove structure and a thinner bulk active layer is described. The cell surface was mechanically grooved and chemically etched. A conversion efficiency of 15.5% for a 10×10 cm polycrystalline silicon cell was obtained with 1.0(%) surplus compared with the texture surface polycrystalline solar cell (reference cell: 14.5%). The grooved surface is effective for minimizing the reflectance of polycrystalline silicon solar cells. A thinner-groove polycrystalline cell of under 200 μm substrate thickness improves the long-wavelength collection efficiency and the conversion efficiency