Journal of the American Ceramic Society, Vol.103, No.4, 2602-2609, 2020
New apatite-type phosphor Ca9La(PO4)(5)(SiO4)F-2:Tb3+,Dy3+ with improved color rendering index
Ca9La(PO4)(5)(SiO4)F-2:Tb3+,Dy3+ (CLPSF:Tb3+,Dy3+) phosphors were successfully prepared using the traditional solid-state technique. The crystal structure was refined and the luminescence properties have been examined in detail. The band gap and electronic structure of Ca9La(PO4)(5)(SiO4)F-2 were performed by the periodic density functional theory (DFT) calculation. The spectral and fluorescence decay dynamics of CLPSF:Tb3+,Dy3+ show that the energy transfer behavior between Tb3+ and Dy3+ ions is observed. The CLPSF:Tb3+,Dy3+ phosphors can be efficiently excitable at the wavelengths range from 300 to 500 nm. The emission spectrum covers the whole visible part of the spectra with the sharp emission bands in red, green, and blue regions. The correlated color temperature (CCT) and color rendering index (CRI) of white light emission could be improved by the fine-tuning of the Tb3+ and Dy3+ ions ration in accordance with the energy transfer behavior. Thus, the CLPSF:Tb3+,Dy3+ phosphor could be used as a material for the near-ultraviolet (n-UV) and white light-emitting diodes (w-LEDs).