Self-Organized Structuring of the Surface of a Metal–Semiconductor Composite by Femtosecond Laser Processing

Abstract

Peculiarities of the laser treatment of a composite consisting of a thin film of a metal (gold) on the surface of a semiconductor substrate [silicon (100)] have been studied. Micro- and nanostructurings of the metal-semiconductor composite sample have been achieved by the irradiation of its initial surface with a Ti : sapphire femtosecond laser. Laser ablation leads to the patterning of the surface of the composite with laser-induced periodic surface structures (LIPSS) and the formation of semiconductor nanohills, metal nanoparticles, and/or nanowires on the top of hills. The presence of some nanoscale surface features is confirmed by a low-frequency shift of the silicon phonon band in Raman spectra. Prepared microstructured surface barrier solar cells are characterized by means of scanning electron microscopy, optical spectroscopy, and photoelectric measurements.