Synthesis and photoluminescence properties of Yb2+ doped Ba5(PO4)3Cl phosphor for white light-emitting diodes

Yb2+ ion doped Ba5(PO4)3Cl phosphor was synthesized by solid state reaction. Four distinct absorption bands were observed in the Ultraviolet (UV) light region due to the electronic transitions of Yb2+ ion from 1S0 ground state to 2F5/2(t2g), 2F5/2(eg), 2F7/2(t2g), and 2F7/2(eg) excited states. The main emission wavelength of the phosphor was around 630 nm. The optimized Yb2+ ion concentration was 0.2 mol% (λexc. = 400 nm). The calculated critical distance was about 8.729 Å and the concentration quenching was observed above 0.2 mol% due to the electric dipole-dipole interaction.