Physical and optical properties of lead doped tellurite glasses

Physical and optical properties of lead telluride (Pb:TZBN) glasses with composition 55TeO(2)-(41-x)ZnO-2Bi(2)O(3)-2Na(2)O-xPbO where x = 1.0, 1.5, 2.0, 2.5% mol are presented. UV-VIS-NIR spectra of the glasses in the range of 300 - 800 nm along with their densities and refractive indices at 746 nm were recorded at room temperature. The optical bandgap energy (E-g) has been calculated from the fitting of Tauc plot. On the basis of these results we found that with the increase of Pb2+ content, their refractive indices are increased while their optical bandgaps are decreased. From this experiment, no distinct relationship between the Pb2+ content variation and the electronic polarizability (alpha(O2-)) as well as their optical basicity values (Lambda) were observed.