Preparation of (Gd,Y)AlO 3:Eu 3+ by citric-gel method and their photoluminescence under VUV excitation

Abstract

By using inorganic salts as raw materials and citric acid as chelating agent, (Gd,Y)AlO 3:Eu 3+ phosphors were prepared by citric-gel method. The single phase of samples was obtained at 1000 °C, which is 600 °C lower than that of traditional solid state reaction. In the excitation spectrum of Gd 0.95Eu 0.05AlO 3 ( λ em = 614 nm ), the broad bands with maximum at 157 and 170 nm are observed and assigned to AlO 3 group absorption and the CT transition of Gd 3+–O 2−, respectively. Under 147 nm excitation, Gd 0.95Eu 0.05AlO 3 shows a typical Eu 3+ emission. The strongest emission peak is located at 614 nm, which is due to 5D 0– 7F 2 transition of Eu 3+. The partial substitution of Y 3+ for Gd 3+ is very convenient to improve the emission intensity of Eu 3+, which is because higher energy is absorbed and transfer to activators efficiently.