Up-conversion luminescence efficiency in Er-doped chalcogenide glasses

• Published in: Journal of non-crystalline solids 2003-10, Vol.326-327, p.311-315
• Main Authors: Tverjanovich, A., Grigoriev, Ya.G., Degtyarev, S.V., Kurochkin, A.V., Man’shina, A.A., Ivanova, T.Yu, Povolotskiy, A., Tveryanovich, Yu.S.
• Format: Article
• Language: English
• ISSN: 0022-3093
• DOI: 10.1016/S0022-3093(03)00420-4

The efficiency of up-conversion luminescence of Er3+ ions (excited by laser light operating at 810 nm) in the GeS2-Ga2S3:Er2S3 system depends on the energy position of the fundamental absorption edge. This dependence is due to non-radiative energy exchange between the electronic subsystem of the glassy matrix and excited levels of Er3+ ions. In chalcogenide glasses Ge and Ga atoms are fourfold coordinated. Except for the M (M=Ge, Ga)-S heterobonds, the rest are M-M homobonds. These homobonds can be detected with Raman spectroscopy. The energy position of the absorption tail of the fundamental band depends on the concentration of M-M homobonds. When the concentration of these bonds increases the absorption edge shifts to longer wavelengths and the intensity of up-conversion luminescence decreases. The relative concentration of M-M bonds depends not only on composition of the glassy matrix but also on the synthesis and on concentration of extrinsic impurities such as OH-, SH- and -CH2-. Another cause of reduction of up-conversion luminescence intensity is the inhomogeneous distribution of REI in the Ga2S3-GeS2 glasses. The simple model describing dependence of luminescence intensity on type of REI distribution in the glassy matrix is discussed. 11 refs.