Optical band gap and luminescence study of yttrium doped neodymium lead borotellurite glass system

Glasses of composition (49-x)H3BO3-35TeO(2)-15PbO-1.0Nd(2)O(3)-xY(2)O(3) (x = 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 mol%) were successfully prepared by a melt-quench method. The effect of Y2O3 on the optical properties of the glasses were investigated by using Uv-Vis NIR and photoluminescence spectroscopy. X-ray diffraction pattern of the prepared glasses exhibits amorphous nature. Absorption spectra of the glasses are recorded in the range 400 - 1100 nm and shows eleven absorption peaks. In order to determine the optical band gap of the glass sample, the Uv-Vis NIR measurement has been carried out in the room temperature. The values of direct and indirect optical band gap initially decreasing before increasing, which were attributed to structural changes induced by the inclusion of Y2O3. The luminescence spectra were obtained under 581 nm wavelength.