Structure and luminescence properties study of Eu~(2+) doped Ca_2Al_(2-x)Si_(1+x)O_(7-x)N_x phosphors based on size-mismatch model

摘要

Eu~(2+) doped Ca_2Al_(2-x)Si_(1+x)O_(7-x)N_x (CASON) green-emitting phosphors were prepared by the high temperature solid state reaction method. The crystal structure and luminescence properties were systematically investigated by X-ray powder diffraction and fluorescence spectrophotometer. It was found that Al-O bond could be substituted by Si-N bond in the Ca_2Al_2SiO_7 lattice with the maximum solubility of about x =0.4. Under the excitation of 360nm, the photoluminescence (PL) spectra of Ca_2Al_(2-x)Si_(1+x)O_(7-x)N_x: Eu~(2+) phosphors presents a blue shift with the increase of x values. The mechanism was discussed in detail by Size-Mismatch model.