Fluorescence improvement of Ba1.3Ca0.7SiO4:Eu2+,Mn2+ phosphors via Dy3+ addition and their color-tunable properties

A series of novel single-phase white phosphors Ba1.3Ca0.69−x−ySiO4:0.01Eu2+,xMn2+, yDy3+ were synthesized by the solid-state method. The excitation spectra of these phosphors exhibit a broad band in the range of 260–410 nm, which can meet the application requirements for near-UV LED chips (excited at 350–410 nm). The emission spectra consist of two broad bands positioned around 455 nm and 596 nm, which are assigned to 5d→4f transition of Eu2+, and 4T1→6A1 transition of Mn2+, respectively. The luminescence intensity of phosphors enhances obviously by doping Dy3+ ions, and the intensity of two bands reaches an optimum when Dy3+ amounts to 2 mol%. In addition, thermoluminescence investigation of phosphor was conducted, getting two shallow trap defects with activation energy of 0.43 eV and 0.45 eV, which demonstrates the energy transfer mechanism of Dy–Eu through the process of hole and electron traps. By precisely tuning the Mn2+ content, an optimized white light with color rendering index (CRI) of Ra=84.3%, correlated color temperature (CCT) of Tc=8416 K and CIE chromaticity coordinates of (0.2941, 0.2937) is generated. The phosphor could be a potential white phosphors for near-UV light emitting diodes.