Theoretical Model and Experimental Analysis for Optical Band Gap

Bulk glassy samples were prepared from high purity (5N) elemental Germanium (Ge) and Selenium (Se).Germanium and selenium chunks were crushed to powders and equivalent ratios of compositions were weight and put into pre-cleaned ampoule.Bulk glasses were prepared from melt quenching technique.Ampoule was sealed under a vacuum pressure of 10 -6 Torr by a torch.The sealed ampoule was put in the thermal furnace; temperature was raised gradually in steps of 25 in every ten minutes up to 1000 and the temperature was monitored by placing a thermocouple at the ampoule position inside the furnace.Ampoule was held at this temperature for 24 hours.During the melting process the ampoule was periodically rotated thoroughly mix the alloy.After the end of 48 hours the ampoules were removed and immediately quenched in ice-water mixture to freeze the glassy structure.The ampoule was then broken to recover the glassy sample.The ingots were polished for optical 2513