Preparation and characterization of telluride glasses

• Published in: Journal of non-crystalline solids 2008-01, Vol.354 (2-9), p.486-491
• Main Authors: Zavadil, J., Pedlikova, J., Zdansky, K., Yatskiv, R., Kostka, P., Lezal, D.
• Format: Article
• Language: English
• Subjects: Absorption; Amorphous materials, glasses and other disordered solids; Chalcogenides; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Conductivity; Exact sciences and technology; Luminescence; Optical; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Photoluminescence; Physics; Rare-earths in glasses; Spectroscopy
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2007.07.084

Chalcogenide bulk glasses Ge20Se80−xTex for x∈(0,10) have been prepared by systematic replacement of Se by Te. Selected glasses have been doped with Er and Pr, and all systems have been characterized by transmission spectroscopy, measurements of dc electrical conductivity and low-temperature photoluminescence. Absorption coefficient has been derived from measured transmittance and estimated reflectance. Both absorption and low-temperature photoluminescence spectra reveal shifts of absorption edge and/or dominant luminescence band to longer wavelength due to Te→Se substitution. Arrhenius plots of dc electrical conductivity, in the temperature range 300–450K, are characterized by activation energies roughly equal to the half of the optical gap. Arrhenius plots for temperatures below 300K yield much lower activation energies. The dominant low-temperature luminescence band centered at about half the band gap energy starts to quench above 200K and a new band appears at 900nm. The band at 900nm, due to band to band transitions, overwhelms the spectra at room temperature. Systems doped with Er exhibit a strong luminescence due to 4I13/2→I15/2 transition of Er3+ ion at 1539nm, and Pr doped samples exhibit a relatively weak luminescence peak at 1590nm, which we tentatively assign to 3F3→3H4 transition of Pr3+ ion.