Synthesis, photoluminescence properties and energy transfer studies of color-adjustable CaSrSiO4:Ce3+,Li+,Mn2+ phosphors

A series of color tunable phosphors CaSrSiO4:Ce3+,Li+,Mn2+ were synthesized by The traditional high temperature solid-state method. The as-prepared CaSrSiO4:Ce3+,Li+ phosphors exhibit a broad excitation band ranging from 250 to 400 nm and give a blue emission band centered at 450 nm. When Mn2+ ions are codoped for the fabrication of CaSrSiO4:Ce3+,Li+,Mn2+ phosphors, another new red-emitting peak appears at near 650 nm corresponding to the spin-forbidden T-4(1)(4G)-(6)A(1)(S-6) transition of the Mn2+ ions. By adjusting the relative concentration of the Ce3+ and Mn2+ ions, the CIE chromaticity coordinate can be modulated from (0.156, 0.106) to (0.224, 0.211) owing to the energy transfer from Ce3+ to Mn2+ ions. The dipole-quadrupole interaction predominates in the energy transfer mechanism. The temperature dependent photoluminescence properties prove that the CaSrSiO4 host has a good thermal stability. These results indicate that CaSrSiO4:Ce3+,Li+,Mn2+ samples show tunable blue/red dual-wavelength emission depending on the codoped ions, which might have potential applications in the white light emitting diodes (wLEDs) and functional sunlight spectrum conversion device as greenhouse for green agriculture. (C) 2015 Elsevier B.V. All rights reserved.