Surface analysis and enhanced photoluminescence via Bi3+ doping in a Tb3+ doped Y2O3 nano-phosphor under UV excitation

The Tb3+, Bi3+ co-doped Y2O3 nano-phosphor has been synthesized through solution combustion method for the first time. The surface analysis of the phosphor has been done using XRD and TEM measurement techniques, which reveal strong crystallinity and spherical particles agglomerated to each other. The EDS spectra of Tb3+, Bi3+ co-doped Y2O3 phosphor show the presence of Y, O, Tb and Bi elements. The Tb3+ doped Y2O3 phosphor emits intense green emission centered at 542 nm due to D-5(4) -> F-7(5) transition along with other weak bands on excitation with 266 nm. The emission intensity is found to be optimum at 1 mol% concentration of Tb3+ ions. The sample annealed at higher temperature gives larger emission intensity due to reduction in the optical quenching centers. The presence of Bi3+ ions in the Tb3+ doped phosphor further enhances the emission intensity of Tb3+ up to two times. The enhancement in the emission intensity is due to energy transfer from Bi3+ to Tb3+ ions, which has been confirmed by lifetime measurements. Thus, the Tb3+, Bi3+ co-doped Y2O3 nano-phosphor may be a suitable candidate for solid state lighting. (C) 2017 Elsevier B.V. All rights reserved.