Electrospun green-emitting La2O2CO3:Tb3+ nanofibers and La2O2CO3:Tb3+/Eu3+ nanofibers with white-light emission and color-tuned photoluminescence

Abstract

Color-tuned luminescence and white-light emission materials have attracted much attention owing to their broad application prospects. Generally, Tb3+ and Eu3+ co-doped phosphors have color-tuned luminescence, but white-light emission is rarely achieved. In this work, color-tunable photoluminescence and white light emission are achieved in Tb3+ and Tb3+/Eu3+ doped monoclinic-phase La2O2CO3 one-dimensional (1D) nanofibers synthesized by electrospinning united with succedent strictly controlling calcination procedure. The prepared samples own excellent fibrous morphology. La2O2CO3:Tb3+ nanofibers are the superior green-emitting phosphors. To obtain 1D nanomaterials with color-tunable fluorescence, particularly those with white-light emission, Eu3+ ions are further selected and doped into La2O2CO3:Tb3+ nanofibers to obtain La2O2CO3:Tb3+/Eu3+ 1D nanofibers. The major emission peaks of La2O2CO3:Tb3+/Eu3+ nanofibers at 487, 543, 596 and 616 nm are attributed to 5D4→7F6 (Tb3+), 5D4→7F5 (Tb3+), 5D0→7F1 (Eu3+) and 5D0→7F2 (Eu3+) energy levels transitions under 250-nm (for Tb3+ doping) and 274-nm (for Eu3+ doping) UV light excitation, respectively. At different wavelengths excitation, La2O2CO3:Tb3+/Eu3+ nanofibers with excellent stability achieve color-tuned fluorescence and white-light emission with the help of energy transfer from Tb3+ to Eu3+ and tuning the doping concentration of Eu3+ ions. Formative mechanism and fabrication technique of La2O2CO3:Tb3+/Eu3+ nanofibers are advanced. The design concept and manufacturing technique developed in this work may offer fresh insights for synthesizing other 1D nanofibers doped with rare earth ions to tune emitting fluorescent colors.