Abstract
The present work aims to theoretically study the effect of Cu concentration through many physical parameters, including coordination number (CN), constraints number (CON), overall mean bond energy ( 〈 E 〉 ) , and cohesive energy (CE), for Ge25Se65Sb10−xCux (where x = 0, 2.5, 5, 7.5 and 10 at%) glasses. As well, the optical constants of the thin films were evaluated via the use of the Swanepoel technique. As the Cu concentration rises, it is found that CN, CON, 〈 E 〉 , and CE also rise. This relationship demonstrates the obvious evidence for incremental rigidity of the Ge25Se65Sb10−xCux glasses with the addition of Cu. The chemical bonds anticipated within the glasses were estimated. It was revealed that the heteropolar bonds occurred in the examined glasses are Cu-Se, Ge-Se and Sb-Se, which have energies of 62.425, 49.441 and 43.981 kcal mol−1, respectively. The acquired estimations of the refractive index (n) of the films were fitted to the two-term Cauchy dispersion equation to get the single oscillator (Eo) and dispersion (Ed) energies. In addition, the estimations of the absorption coefficient ( ) were acquired using the conditions suggested by Connell and Lewis. An energy gap (Eg) decrement from 1.79 to 1.47 eV was prompted by a Cu concentration rise from 0 to 10% at%.