Multiphonon energy gap law in rare-earth doped chalcogenide glass

• Published in: Journal of non-crystalline solids 2003-06, Vol.320 (1), p.100-112
• Main Authors: Quimby, R.S, Aitken, B.G
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Other solid inorganic materials; Photoluminescence; Physics
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/S0022-3093(03)00030-9

The parameters for multiphonon relaxation of rare earth (RE) ions in the sulfide glass Ge 25As 8.33Ga 1.67S 65 have been re-evaluated using the temperature dependence of the fluorescence lifetime to separate out true multiphonon decay from other non-radiative processes. It is found that for energy gaps to the next lowest level greater than 2500 cm −1, other non-radiative processes become dominant over multiphonon decay. The most likely process for this additional non-radiative decay is energy transfer to vibrational impurities such as OH and SH. The newly derived parameters lead to an electron–phonon coupling parameter ϵ=0.058, which is more in line with other glass types than the previously accepted value of ϵ=0.36. These new multiphonon relaxation parameters and the existence of additional non-radiative decay mechanisms has implications for the modeling of chalcogenide-based active devices.