Random Si nanopillar fabrication by spontaneous dewetting of indium for broadband antireflection

We introduce and demonstrate a cost-effective method for the fabrication of random short Si nanopillars using metal-assisted chemical etching for effective light trapping in crystalline Si wafers. Random crystalline Si nanopillars were fabricated by metal-assisted etching of the crystalline Si wafers using Au nanohole thin films as a metal catalyst. The Au nanohole thin films were prepared by thermal evaporation of Au onto crystalline Si wafers with indium nanoparticles serving as shadow masks. Indium nanoparticles were synthesized by thermal evaporation and spontaneous dewetting at room temperature. The Si nanopillars height could be adjusted by varying the etching time. The improved broadband antireflectance provided by the fabricated crystalline Si nanopillars was confirmed by measurements of the total light absorption of the Si wafers.