Effect of partial nitridation on the structure and luminescence properties of melilite-type Ca2Al2SiO7:Eu2+ phosphor

Abstract Ca 1.97 Al 2− x Si 1+ x O 7− x N x :0.03Eu 2+ ( x = 0–0.4) phosphors have been prepared by using the high temperature solid-state reaction. The effect of phase structures, photoluminescence (PL) properties and the thermal stabilities have been investigated based on the substitution of Al–O bond in Ca 2 Al 2 SiO 7 :Eu 2+ phosphor with Si–N bond. The XRD Rietveld refinement and 29 Si NMR analysis results verify the introduction of partial Si–N bonds. It is found that the PL spectra shift to the blue region abnormally from 530 to 515 nm, and the possible mechanism has been proposed. The activation energy becomes large along with the nitridation process, which coincides with the explanation of configuration coordinate diagram.