Temperature-dependent photoluminescence properties of deep-red emitting Mn~(4+)-activated magnesium fluorogermanate phosphors

摘要

Deep-red emitting Mn~(4+)-activated magnesium fluorogermanate (MFG:Mn~(4+)) phosphors have been syn thesized by the solid-state reaction technique. Temperature-dependent photoluminescence properties of MFG:Mn~(4+) phosphors with various activator concentrations (0.001-0.015) were studied. The temper ature dependence relation of the Mn~(4+) ions luminescence depends on activator concentrations, excitation wavelengths and emission bands that are measured. This luminescent temperature effect can be explained by the shifts of excitation spectra with temperature and the thermally activated concentration quenching. The MFG:Mn~(4+) phosphors can be effectively excited by near-UV or blue light and emit deep-red light, and simultaneously exhibit excellent resistibility against luminescent thermal quenching in the temperature range from 30 to 200 °C, which make them promising candidates of deep-red phosphors for white-LEDs applications.