Synthesis and photoluminescence properties of novel LaGa0.5Sb1.5O6: Eu3+, Dy3+, Tb3+ and BiGeSbO6: Eu3+, Dy3+, Tb3+ phosphors

Abstract

In this work, novel phosphors LaGa0.5Sb1.5O6 and BiGeSbO6 doped with Eu3+, Tb3+, and Dy3+ were synthesized, and the luminescent properties were studied. The impact of the host type on the emission properties was demonstrated for compositions singly doped with Eu3+ and Dy3+ ions. For the La1−xEuxGa0.5Sb1.5O6 and Bi1−xEuxGeSbO6 (x = 0.05–0.5) solid solutions, there were evident differences in the luminescence intensity ratio of the bands caused by the 5D0→7F1 and 5D0→7F2 transitions of Eu3+ that may have resulted from a different rare earth (RE) ion coordination environment. The spectra of all the bismuth-containing solid solutions were characterized by the appearance of an additional band related to the intrinsic luminescence of the bismuth-containing host. The intensity ratio of this band and the RE ion emission lines for dysprosium-containing compounds was much higher than that for compositions doped with praseodymium and europium. Co-doping with Eu3+, Dy3+, and Tb3+ ions led to a shift in the emission colour to orange (when doped with two types of RE ions) and yellow-orange (when doped with three types of RE ions).