AB-INITIO CALCULATIONS OF THE DIELECTRIC CONSTANT, OPTICAL ABSORPTION AND THE REFRACTIVE INDEX OF ZN1-XBEXO ALLOY

The optical properties of Zn1-xBexO were studied by first principle method using the density functional theory. The dielectric function and optical constants are calculated using PP-PW method within the generalized gradient approximation (GGA). The theoretical calculated optical properties yield a static dielectric constant for Zn1-xBexO are 4.08, 3.86, 3.60, 3.12 and 2.85 along polarization direction (001). It indicates that the static dielectric constants reduce with increasing Be concentration. However a static refractive indices for Zn1-xBexO are found to be 2.05, 1.98, 1.88, 1.77 and 1.70 with the increasing x, respectively. The obtained results agree well with the available theoretical and experimental values.