Emission properties and temperature dependence of Cu⁺ luminescence in the CaO-CaF₂-P₂O₅ ternary glass system co-doped with CuO and SnO

Abstract Co-doping of the (50-x)CaO-xCaF₂-50P₂O₅ (x=0,10, and 20) ternary glass system with CuO and SnO has been realized by the melt-quenching technique with the purpose of investigating on material photoluminescence (PL). The glasses display tunable luminescence by variation of excitation wavelength in connection with the distinct excitation/emission properties of Cu⁺ ions and Sn centers. Substitution of CaO by CaF₂ appeared to support the Cu⁺ luminescence process. Analyses of emission decay dynamics suggest that both luminescent species exist primarily coordinated to oxygen atoms in the oxyfluorophosphate hosts. Further, the effect of temperature on Cu⁺ PL was evaluated from room temperature to 300°C. An increase in the activation energy for the thermal quenching of Cu⁺ PL was observed upon the substitution of oxygen by fluorine ions. Accordingly, the Cu⁺-doped oxyfluorophosphate matrix shows potential as thermally-stable glass for optical device applications (e.g. lighting, solar cells).