Structure and Photoluminescence of Eu²⁺Doped Sr₂Al₂SiO₇Cyan-Green Emitting Phosphors

Eu2+ doped Sr2Al2SiO7 cyan-green emitting phosphors have been synthesized with solid-state reaction method. With Rietveld refinement technique, Sr2Al2SiO7 equivalent sites and atomic positions were acquired. The Sr2Al2SiO7:Eu2+ photoluminescence at room and high temperature were investigated. This phosphor shows the Eu2+ broad band excitation and emission spectra corresponding to Eu2+ transitions between the 4f 7 ground state and the lower 4f 65d1 crystal splitting states. The luminescent properties as a function of Eu2+ concentration were investigated. The mechanism of dipole-dipole interaction dominates the non-radiative energy transfer between the Eu2+ luminescent centers and causes the concentration quenching of this phosphor. The radiation re-absorption is proposed to be the mechanism for the emission red shift. The emission band shows slight blue shift with increased temperature. Sr2Al2SiO7:Eu2+ is a kind of promising blue to cyan emitting phosphor.