Preparation and up‐conversion luminescence properties of LaOBr:Yb3+/Er3+ nanofibers via electrospinning

LaOBr:Yb3+/Er3+ nanofibers were synthesized for the first time by calcinating electrospun PVP/[La(NO3)3 + Er(NO3)3 + Yb(NO3)3 + NH4Br] composites. The morphology and properties of the final products were investigated in detail using scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS), X-ray diffractometry (XRD) and fluorescence spectroscopy. The results indicate that LaOBr:Yb3+/Er3+ nanofibers are tetragonal in structure with a space group of P4/nmm. The diameter of LaOBr:Yb3+/Er3+ nanofibers is ~ 147 nm. Under the excitation of a 980-nm diode laser, LaOBr:Yb3+/Er3+ nanofibers emit strong green and red up-conversion emission centering at 519, 541 and 667 nm, ascribed to the 2H11/2, 4S3/2  4I15/2 and 4 F9/2  4I15/2 energy-level transitions of Er3+ ions, respectively. The up-conversion luminescent mechanism of LaOBr:Yb3+/Er3+ nanofibers is advanced. Moreover, near-infrared emission of LaOBr:Yb3+/Er3+ nanofibers is obtained under the excitation of a 532-nm laser. The formation mechanism of LaOBr:Yb3+/Er3+ nanofibers is proposed. LaOBr:Yb3+/Er3+ nanofibers could be important up-conversion luminescent materials. Copyright © 2014 John Wiley & Sons, Ltd.