Sol–gel synthesis and photoluminescence properties of a novel Dy3+ activated CaYAl3O7 phosphor

Abstract

A series of Dy3+ activated CaYAl3O7 phosphors were successfully synthesized by sol–gel method. The as-prepared phosphors were characterized by X-ray power diffraction (XRD) and photoluminescence (PL). The XRD results indicate that the main phase of the phosphors is CaYAl3O7. Furthermore, the substitution of Dy3+ ions for Y3+ ions gives rise to the diffraction peaks shifting towards smaller angle. The results of PL suggest that the strongest excitation peak at 350 nm is attributed to 6H15/2 to 6P7/2 transition and the emission spectra consist of two intense bands in blue and yellow regions corresponding to 4F9/2 → 6H15/2, 4F9/2 → 6H13/2 transitions, respectively. Therefore, the white-light emission can be achieved. The ratio of yellow emission intensity to blue emission intensity keeps stable along with the doping concentration, implying the structural distortion around Dy3+ sites changes little in the host. Moreover, the emission intensity reach the maximum at 6 at.% doping concentration and the electric dipole–dipole (d–d) interaction is confirmed to be responsible for the energy transfer between Dy3+ ions. These results indicate that Dy3+ activated CaYAl3O7 phosphors have a potential for possible applications in solid-state lighting and display.