Surface nano-texturing of silicon by Picosecond laser irradiation through TiO2 nanotube arrays

This article presents, nano-texturing of crystalline silicon by irradiating Picosecond laser with variable spatial intensity, caused by optically non-linear TiO2 nanotube arrays (TNTA). Along with micro-scale surface structure, highly ordered laser-induced periodic surface structures (LIPSS) was observed at nano-scale. The periodicity (Λ) of the LIPSS generated was near to the laser wavelength (532 nm). Surface morphology at micro-level was characterized by Optical Microscopy (OM) and White Light Interferometer (WLI) and at the nano-scale by Scanning Electron Microscope (SEM) and atomic force microscope (AFM). The results highlight the potential use of TNTA as a single step process to produce Micro/Nanostructures without any gas/liquid medium under ambient condition.