Laser Irradiation Effect on the Optical Band Gap of Se96-xTe4Hgx Thin Films

The effect of laser irradiation on the optical band gap of Se96-xTe4Hgx thin films has been studied. Thin films of thickness 300 nm have been deposited on glass substrate by using thermal evaporation technique. The result shows that irradiation causes a red shift in the absorption edge and hence optical band gap decreases with increasing irradiation time. The results have been analyzed on the basis of laser irradiation-induced defects in the film. Furthermore, optical band gap has found to decrease by increasing mercury concentration and optical band gap decreases rapidly with a higher concentration of mercury.