Tunable and White‐Light Emission from Single‐Phase Ca 2 YF 4 PO 4 :Eu 2+ ,Mn 2+ Phosphors for Application in W‐LEDs

Novel phosphors, Ca 2 YF 4 PO 4 :Eu 2+ ,Mn 2+ , 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 Ca 2 YF 4 PO 4 :Eu 2+ ,Mn 2+ 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 Eu 2+ and Mn 2+ ions, respectively. Energy transfer from the Eu 2+ to Mn 2+ ions in the Ca 2 YF 4 PO 4 host matrix was observed and studied by luminescence spectrosccopy as well as the lifetime of the Eu 2+ ions. The emission color of the Ca 2 YF 4 PO 4 :Eu 2+ ,Mn 2+ samples can be adjusted from blue to yellow under excitation by UV radiation of 375 nm by adjusting the Eu 2+ and Mn 2+ concentrations, and white‐light emission with chromaticity coordinates (0.327, 0.312) was obtained with the Ca 2 YF 4 PO 4 :0.015Eu 2+ ,0.015Mn 2+ sample. In addition, the temperature‐dependent photoluminescence of the as‐prepared phosphors has been investigated in detail. The results revealed that the Ca 2 YF 4 PO 4 host has good thermal stability. The stable structure of the host and tunable luminescence suggest that Ca 2 YF 4 PO 4 :Eu 2+ ,Mn 2+ could be regarded as a good candidate for UV LED‐based white‐light emitting diodes.