Enhanced light absorption of amorphous silicon thin film by substrate control and ion irradiation

Large-area periodically aligned silicon nanopillar (PASiNP) arrays were fabricated by magnetic sputtering with glancing angle deposition (GLAD) on substrates coated by a monolayer of close-packed polystyrene (PS) nanospheres. The structure of PASiNP arrays could be manipulated by changing the diameter of PS nanospheres. Enhanced light absorptance within a wavelength range from 300 to 1,000 nm was observed as the diameter of nanopillars and porosity of PASiNP arrays increased. Meanwhile, Xe ion irradiation with dose from 1 × 10(14) to 50 × 10(14) ions/cm(2) was employed to modify the surface morphology and top structure of thin films, and the effect of the irradiation on the optical bandgap was discussed. PACS CODE: 81.15.Cd; 78.66.Jg; 61.80.Jh