Effect of substrate temperature on structural and linear and nonlinear optical properties of nanostructured PLD a-SiC thin films

In this paper, the effect of substrate temperatures (T-s) on the structural, linear and non-linear optical properties of nanostructured amorphous Silicon Carbide (a-SiC) thin films deposited onto fused silica by pulsed-laser deposition technique is reported. The structural and compositional properties were studied by X-ray diffraction, Raman spectroscopy and Fourier transform Infrared spectroscopy. A transition from Silicon-rich SiC to nearly stoichiometric SiC was observed with increasing T-s. The absorption coefficient (alpha), refractive index (n), optical band gap and thickness of the films were determined from UV-vis-IR spectra. Static refractive indices of the films were found to vary from 2.99-2.54 with the increasing T-s. The optical band gap of the films was found to be increasing from 1.5 eV to 2.33 eV with increase in T-s. The third order non-linear optical susceptibility (chi((3))) of the a-SiC thin films estimated from Z-scan studies was found to be of the order of 10(-3) esu. (C) 2016 Elsevier Ltd. All rights reserved.