Surface Periodic Nanostructure of p-GaSb Irradiated by Femtosecond Laser and Optical Properties Research

We report the fabrication of nanostructures on p-GaSb surface using femtosecond laser. The scanning electron microscopy images suggest that the nanoscale ripples appeared with the condition of femtosecond laser-induced pulse energy between 30 mJ/cm(2) and 90 mJ/cm(2), and the surface ripples orientation perpendicular to the polarization direction of the incident laser. Period of the nanostructures are 460-770 nm, shorter than the laser wavelength and appears as a result of surface instability. In addition, for further research on optical properties, the nanostructures were characterized by low-temperature photoluminescence spectra, Raman spectra and X-ray diffraction. All the results indicate that the different defects and nanostructures are formed in the surface of the laser-induced samples.