Fabrication of silicon nanowire arrays based solar cell with improved performance

We report fabrication of solar cell (n+–p–p+ structure) on black silicon substrates consisting of silicon nanowire (SiNW) arrays prepared by Ag induced wet chemical etching process in aqueous HF–AgNO3 solution. SiNW arrays surface has low reflectivity (<5%) in the entire spectral range (400–1100 nm) of interest for solar cells. The solar cells were fabricated by conventional cell fabrication protocol. Performance of three types of cells, namely cell with SiNW over the entire front surface, cell with SiNW only in the active device area and control cell (on planar surface), has been compared. It was found that cell based on selectively grown shorter length SiNW arrays has the best cell performance.