Enhanced 2H11/2/4S3/2 → 4I15/2 transitions in high-symmetry Er, Y:CaF2 phosphors through introducing Y3+ ions as buffers

Er, Y:CaF 2 particles were synthesized using the chemical precipitation method, and as-synthesized particles were calcined at different temperatures. Fourier-transform infrared spectra confirmed the elimination of residual nitrates from Er, Y:CaF 2 phosphors calcined at 600 °C. Measurements revealed that the calcined Er, Y:CaF 2 phosphors displayed a single cubic-fluorite crystal structure with regular polygon shapes. We investigated the sensitivity effects of introducing non-active Y 3+ ions as buffers on the luminescence characteristics of Er, Y:CaF 2 phosphors under 488 nm and 980 nm excitation. Two emission bands were detected in luminescence spectra. For phosphors under 980 nm excitation, a three-photon UC mechanism is identified to be involved in the generation of green and red emissions. The findings provide insights into enhancing the 2 H 11/2 / 4 S 3/2  →  4 I 15/2 transitions in Er, Y:CaF 2 phosphors by introducing Y 3+ ions as buffers.