Optical and other structural properties of some zinc vanadate semiconducting glasses

In this paper we have reported the optical and other structural properties for different compositions of xV<SUB>2</SUB>O<SUB>5</SUB>-(1-x)ZnO (x=0.5-0.8) semiconducting glasses. It has been observed that the density and the glass-transition temperature increase, while the molar volume decreases with the decrease of the V<SUB>2</SUB>O<SUB>5 </SUB>content in the compositions. It has also been observed from the analysis of FT-IR spectra that the network structure of these glasses consists of VO<SUB>4</SUB>-polyhedra. The fundamental absorption edge for the present glasses has been analyzed using the theory proposed by Davis and Mott. It has been observed that the fundamental absorption edge and cut-off wavelength shift towards red with the increase in V<SUB>2</SUB>O<SUB>5</SUB> content. The composition dependence of the optical gap is consistent with that of the activation energy for the dc electrical conductivity