Synthesis and luminescence of high-brightness Gd2O2SO4:Tb3+ nanopieces and the enhanced luminescence by alkali metal ions co-doping

Gd2O2SO4:Tb3+ nanopieces were synthesized by a combined approach of electrospinning and calcination at 1000 degrees C in mixed gas of sulfur dioxide and air. The nanopieces excited by a 230 nm light showed excellent green luminescence with the strongest emission peak at 545 nm due to the D-5(4) -> F-7(5) transition of Tb3+. Interestingly, the intensity of emission peak at 545 nm of Gd2O2SO4:Tb3+ nanopieces exhibited about two times stronger than that of the bulk Gd2O2SO4:Tb3+ at the same doping concentrations of Tb3+. Besides, the effects of alkali metal ions doping on the luminescence of the nanopieces have been examined. The emission intensities were further enhanced by alkali metal ions doping, especially for Gd2O2SO4:Tb3+/Li+. The optimal doping concentration of Li (+) was 7%. (C) 2014 Elsevier B.V. All rights reserved.