Performance of silicon nanowire solar cells with phosphorus-diffused emitters

Vertical silicon nanowire (Si NW) arrays on a Si (100) substrate have been prepared by using a low-cost and facile Ag-assisted chemical etching technique. The reflectance of Si NW arrays is very low (<1%) in the spectral range from 400 to 1000 nm. By phosphorus diffusion into Si NW arrays to fabricate solar cells, the power conversion efficiency of 8.84% has been achieved. This power conversion efficiency is much higher than that of the planar cell with the similar celling technology. It is found that the efficiency of Si NW solar cells is intimately associated with their excellent antireflection property. The surface recombination of Si NWs is the main obstacle for the improvement of solar cell efficiency. The current results are helpful to the advancement of the application of Si NWs in photovoltaics.