Tunable luminescence and energy transfer properties of Ca19Mg2(PO4)14:Ce3+, Tb3+, Mn2+ phosphors

A series of single-composition phosphors Ca19Mg2(PO4)14 (CMPO):Ce3+, Tb3+, Mn2+ have been prepared via a high-temperature solid-state reaction process. X-ray diffraction (XRD), scanning electric microscopy (SEM), and photoluminescence (PL) spectra were utilized to characterize the samples. The luminescence properties of Ce3+ in CMPO have been discussed. Both of energy transfers (ETs) processes from Ce3+ to Tb3+/Mn2+ have been demonstrated to be a resonant type via the dipole-quadrupole interaction mechanism, respectively. The emissive colors of CMPO:Ce3+, Tb3+, Mn2+ samples can be adjusted from purplish blue to green/red by the ETs of Ce3+ → Tb3+/Mn2+, respectively. More importantly, white light emission has been obtained through adjusting the relative concentrations of Ce3+, Tb3+ and Mn2+ ions in the CMPO host under UV. The results suggest the present phosphors can be potentially applied as a candidate of single-component white-light phosphor for UV-pumped w-LED.