Band gap determination by absorption spectrum fitting method (ASF) and structural properties of different compositions of (60−x) V2O5–40TeO2–xSb2O3 glasses

Glasses with compositions (60−x) V2O5–40TeO2–xSb2O3 with 0 ⩽ x ⩽ 10 (in mol%) have been prepared using usual melt quenching method. The position of the absorption edge and hence the values of the optical band gap was found to depend on the glass composition. Using the Tauc model, the absorption spectrum fitting method (ASF) was employed to obtain the optical band gap. This method requires only the measurement of the absorbance spectrum of the sample. For each sample, the width of the band tail was determined. Also, the density and glass transition temperature values indicate that the rigidity and packing of the samples increase with increase in Sb2O3 concentration.