Abstract
In this work, an approach to achieve surface nano-protrusions on a chalcopyrite CuIn(S,Se) 2 thin film was demonstrated. Home-made CuInS 2 nanocrystals with average diameter of 20 nm were prepared and characterized. By applying ion erosion process on the CuIn(S,Se) 2 film, large-area self-aligned nano-protrusions can be formed. Interestingly, the process can be applied on flexible substrate where the CuIn(S,Se) 2 film remains intact with no visible cracking after several bending tests. In addition, reflectance spectra reveal the extraordinary anti-reflectance characteristics of nano-protrusions on the CuIn(S,Se) 2 film with the incident light from 350 to 2000 nm. A 36-cm 2 CuIn(S,Se) 2 film with nano-protrusions on flexible molybdenum foil substrate has been demonstrated, which demonstrated the feasibility of developing low cost with a high optical absorption CuIn(S,Se) 2 flexible thin film.