Photoluminescence properties and energy transfer of a color tunable phosphor: Dy 3+ and Tm 3+ co-activated SrCaAl 2 SiO 7

Abstract A series of single-phased emission-tunable SrCaAl2SiO7:Dy3+, Tm3+ phosphors were successfully synthesized by solid-state reaction process. By controling the energy transfer, the emission colors could be tuned from blue to yellow, including the white light region. It was discovered that the energy is transferred from Tm3+ to Dy3+ by luminescence spectra and decay curves. The resonance-type energy transfer from Tm3+ to Dy3+ was demonstrated to be via the dipole–dipole mechanism. By changing the doping concentration of Dy3+ and Tm3+ in SrCaAl2SiO7, the sample with corresponding color coordinates close to the white color chromaticity coordinates (x = 0.33, y = 0.33) could be realized.