Tuning of luminescent properties of Zn1-xMgAl10O17:Eux nano phosphor

Abstract

The Zn1-xMgAl10O17:Eux2+ (x = 0.01–0.4) nano phosphors were prepared successfully using the combustion route by employing urea as a fuel. The structural, microstructural, thermal, optical and luminescent properties were measured on the samples. The nano phosphors were found to be of surface area (∼13.92 m2/g) and insulators of the band gap (∼5.24eV). Photoluminescence properties on the samples were characterized by excitation (λex. = 340 nm) and emission (λem. = 440 nm) spectra. The phosphors showed strong blue luminescence (440 nm-460 nm) as well as showed weak luminescence in 577 nm, 589 nm, 596 nm, and 615 nm in the orange-red region, which are attributed to 4f65 d1→4f7 and 5D0→7Fj (j = 0, 1,…) transitions of the Eu (II) and Eu (III) ions respectively. The tuning of this blue luminescent properties as compared to the earlier reported red luminescence has been achieved. Thermo-luminescence glow curve recorded under 10-minute dose of UV (254 nm) radiation have been used to calculate the kinetic parameters and the activation energy of the nano phosphors by using the Chens-equation. The TL emission spectra of the Zn0.99MgAl10O17:Eu0.01 phosphor showed the characteristic Eu2+ emission peaks ∼450 nm (blue) originating from the transitions 4f65 d1→4f7. The possible mechanism of the PL and TL of blue light emitting phosphor are also discussed.