Preparation and characterization of sulfide, selenide and telluride glasses

Chalcogenide glass systems As-S, As-Se, As-S-Se and Ge-Se-Te and those doped with rare-earth (RE) elements have been prepared and characterized by absorption spectroscopy, scanning electron microscopy and low-temperature photoluminescence. Photoluminescence spectra have been measured over a wide temperature range and the role of multi-phonon transitions in mediating the inner 4f-4f electronic transitions of excited RE3+ ions was demonstrated. A peculiar Pr related band at 1600 nm has been found in some samples. The shift of the dominant luminescence band to higher energies with increasing temperature has been observed. Both position and line width of the luminescence band are not strongly temperature dependent at lower temperatures but considerable dependence appears when room temperature is approached. (C) 2003 Elsevier B.V. All rights reserved.