Energy transfer studies of Ce~(3+)-Mn~(2+) and Ce~(3+)-Tb~(3+) in an emitting tunable Mg_2Al_4Si_5O_(18):Ce~(3+)/Mn~(2+)/Tb~(3+) phosphor

摘要

An emitting tunable Mg_2Al_4Si_5O_(18):Ce~(3+)/Mn~(2+)/Tb~(3+) phosphors have been synthesized by high-temperature solid-state reaction technique. In this system, Mg_2Al_4Si_5O_(18):Ce~(3+), Mn~(2+) samples exhibit two dominating bands situated at 430 and 640 nm, originating from the Ce~(3+), Mn~(2+) ions, respectively. Photoluminescence and energy transfer in Mg_2Al_4Si_5O_(18):Ce~(3+), Mn~(2+) are investigated as a function of Mn~(2+) concentrations. The intensity ratios of red to blue band as a function of Mn~(2+) concentrations are calculated based on the analysis of the luminescence dynamical process as well as fluorescence lifetime measurements, and the results are in good agreement with that obtained directly from emission spectra. Additionally, by incorporation of Tb~(3+), an efficient energy transfer from Ce~(3+) to Tb~(3+) was found and the energy transfer efficiency reaches 52% at y = 0.05. Results indicated that the emitting colors can be adjusted from blue to red via the energy transfer of Ce~(3+) → Mn~(2+) and from blue to green via the energy transfer of Ce~(3+) → Tb~(3+).