A series of single-component emission-tunable Ca8MgR(PO 4)7:Eu2+,Mn2+ (R = La, Y) phosphors were synthesized via high-temperature solid-state reaction. The crystal structure, photoluminescence (PL), PL excitation (PLE) spectra and decay time were investigated in detail. The results indicate that Ca 8MgLa(PO4)7:Eu2+ can be a green candidate for application in near UV-chip pumped white light-emitting diode (LED). The emission color of Eu2+ doped Ca8MgLa 1-xYx(PO4)7 phosphor can be tuned from green to cyan by changing the ratio of La3+ and Y3+ to decrease the crystal field strength. In addition, a standard white-light emitting single-phased phosphor of Ca8MgY(PO4) 7:Eu2+,Mn2+ with CIE color coordinate of (0.330, 0.328) is realized via energy transfer between Eu2+ and Mn2+. The energy transfer was demonstrated to be a resonant type dipole-quadrupole mechanism and the critical distance was calculated. A white LED was successfully fabricated by coating the white-emitting single-composition Ca7.88Mg0.85Y(PO4)7:0.12Eu 2+,0.15Mn2+ phosphor onto a near UV 375 nm chip which indicates that Ca8MgY(PO4)7:Eu 2+,Mn2+ is a powerful candidate for phosphor of near UV-based white LEDs.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials