Enhanced green emission from Tb 3+–Bi 3+ co-doped GdAlO 3 nanophosphors

Abstract

Bi 3+ and Tb 3+ ions co-doped GdAlO 3 (GAP) nanophosphors have been synthesized by means of solvothermal reaction method. The XRD pattern of GAP phosphor confirms their orthorhombic phase. The luminescence properties of these phosphors have been explored by analyzing their excitation and emission spectra along with their decay curves. The excitation spectra of GAP:Tb 3+, Bi 3+ phosphors consist of a broad band in the shorter wavelength region due to the 4f 8 → 4f 75d 1 transition of Tb 3+ ions overlapped with the 6s 2 → 6s 16p 1 ( 1S 0 → 3P 1) transition of Bi 3+ ions and some sharp peaks in the longer wavelength region due to f → f transitions of Tb 3+ ions. The present phosphors exhibit green color due to strong 5D 4 → 7F 5 transition of Tb 3+ ions. The emission intensity was enhanced by co-doping with Bi 3+ ions under 292 nm excitation, which indicate that the efficient energy transfer occurred from Bi 3+ to Tb 3+ ions.