Tunable and White-Light Emission from Single-Phase Ca2YF4PO4:Eu2+,Mn2+ Phosphors for Application in W-LEDs

Novel phosphors, Ca2YF4PO4:Eu2+,Mn2+, have been prepared by high‐temperature solid‐state reactions. XRD and XPS techniques were used to investigate the purity and composition of the as‐prepared samples. The Ca2YF4PO4:Eu2+,Mn2+ phosphors exhibit broad excitation spectra ranging from 275–420 nm and the emission spectra show a broad blue emission band centered at 455 nm and a yellow emission band centered at 570 nm, which originate from the Eu2+ and Mn2+ ions, respectively. Energy transfer from the Eu2+ to Mn2+ ions in the Ca2YF4PO4 host matrix was observed and studied by luminescence spectrosccopy as well as the lifetime of the Eu2+ ions. The emission color of the Ca2YF4PO4:Eu2+,Mn2+ samples can be adjusted from blue to yellow under excitation by UV radiation of 375 nm by adjusting the Eu2+ and Mn2+ concentrations, and white‐light emission with chromaticity coordinates (0.327, 0.312) was obtained with the Ca2YF4PO4:0.015Eu2+,0.015Mn2+ sample. In addition, the temperature‐dependent photoluminescence of the as‐prepared phosphors has been investigated in detail. The results revealed that the Ca2YF4PO4 host has good thermal stability. The stable structure of the host and tunable luminescence suggest that Ca2YF4PO4:Eu2+,Mn2+ could be regarded as a good candidate for UV LED‐based white‐light emitting diodes. The tunable luminescence and energy‐transfer properties of Ca2YF4PO4:Eu2+,Mn2+ phosphors with potential application in LEDs have been investigated.