Structure and luminescence properties study of Eu²⁺doped Ca2Al2−xSi1+xO7−xNxphosphors based on size-mismatch model

摘要

Eu²⁺doped Ca2Al2−xSi1+xO7−xNx(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 Ca2Al2SiO7lattice with the maximum solubility of about x =0.4. Under the excitation of 360nm, the photoluminescence (PL) spectra of Ca2Al2−xSi1+xO7−xNx: Eu²⁺phosphors presents a blue shift with the increase of x values. The mechanism was discussed in detail by Size-Mismatch model.