Abstract
One-step facile methodology to create nanotip arrays on chalcopyrite materials (such as CuInS <sub>2</sub> , Cu(In,Ga)S <sub>2</sub> , CuInSe <sub>2</sub> , and Cu(In,Ga)Se <sub>2</sub> ) via a low energy ion beam bombardment process has been demonstrated. The mechanism of formation for nanotip arrays has been proposed by sputtering yields of metals and reduction of metals induced by the ion beam bombardment process. The optical reflectance of these chalcopyrite nanotip arrays has been characterized by UV-vis spectrophotometer and the efficient light-trapping effect has been observed. Large scale (∼4′′) and high density (10 <sup>10</sup> tips/cm <sup>2</sup> ) of chalcopyrite nanotip arrays have been obtained by using low ion energy (< 1 kV), short processing duration (< 30 min), and template-free. Besides, orientation and length of these chalcopyrite nanotip arrays are controllable. Our results can be the guide for other nanostructured materials fabrication by ion sputtering and are available for industrial production as well. © 2014 American Chemical Society.