Spectroscopic studies in glassy semiconducting Ge xSe 1− x

Abstract

The dependence of the structure and the nature of chemical bonds on amorphous alloyed samples of Ge x Se 1- x , prepared under Vacuum with x=0.05, 0.15 and 0.30, were discussed in terms of the spectroscopic approach. The results of the X-ray diffraction technique, and the radial distribution function (RDF), have evidences that amorphous Ge x Se 1- x substantially consists of four-fold coordination of Ge atom and two fold of Se atom. The average interatomic distance and the average coordination number, for the three amorphous samples were determined from the main first and second peaks in the RDFs. These peaks are 0.244 (0.246 nm) for r 1 and 0.386 (0.396 nm) for r 2, respectively. It was found that there is a correlation between the glass forming ability and the number of lone-pair electrons for our glassy system. The theoretical investigation are in accordance with Liang criterion for computing the ability of chalcogenide system to retain its vitreous states. Our experimental and theoretical results were discussed in light of the topological bonding structure, which involves a hierarchy of correlation ranges in short.