Fabrication of an ant-nest nanostructure in polycrystalline silicon thin films for solar cells

A silicon nanostructure is fabricated in polycrystalline silicon thin films by metal-assisted wet chemical etching using thermally annealed silver nanoparticles as a catalyst. The Si nanostructure has an ant-nest feature. Solar cells based on the silicon nanostructure gives 90% short-circuit current enhancement compared to the cells based on the planar film. We also report that Al2O3 passivation of the silicon nanostructure provides a new approach to improving the polycrystalline silicon thin film’s electrical property. The open-circuit voltage of the Al2O3 passivated cells is improved by 70 mV.