STUDY OF OPTICAL BAND GAP OF ZINC-BORATE GLASSES
M. Altaf, M. Ashraf Chaudhry and Maria Zahid
Department of Physics B. Z. University, Multan 60800, Pakistan.
Abstract: The present study deals with binary xZnO-(100-x)B2O3 (x=50-60%) and ternary yV2O5-50ZnO-(50-y)B2O3 (y=5-10%) glass systems. The mass density, oxygen packing density, molar volume and optical energy gap of these glasses were measured at room temperature. The density varies in the range of 2.92 – 3.57 g/cm3. The absorption spectra of these glasses were recorded in the UV-visible range. The optical band gap energies for these glasses were estimated from absorption data using the Mott and Davis relation and found to be in the range of 1.14~2.92 eV. These results show that Eopt decreases with decreasing concentration of ZnO in binary glasses. In ternary glasses Eopt decreases with increasing concentration of V2O5 for a fixed amount of ZnO.
Keywords: Absorption spectra, borate glasses, optical energy gap, oxygen packing density.