Electrospinning preparation of LaOBr:Tb3+ nanostructures and their photoluminescence properties

Tb3+-doped LaOBr nanostructures including nanofibers, nanobelts, and hollow nanofibers were synthesized for the first time via calcinating the electrospun polyvinyl pyrrolidone/[La(NO3)(3) + Tb(NO3)(3) + NH4Br] composites. X-ray diffraction analysis revealed that LaOBr:Tb3+ nanostructures are tetragonal in structure with space group of P4/nmm. The morphologies and sizes of LaOBr:Tb3+ nanostructures were investigated using scanning electron microscope and transmission electron microscope. Under the excitation of 254-nm ultraviolet light, LaOBr:Tb3+ nanostructures exhibit the green emissions of predominant peak at 543 nm, which is ascribed to D-5(4) -> F-7(5) transition of Tb3+ ions. It is found that the optimum doping concentration of Tb3+ ions in the LaOBr:Tb3+ nanofibers is 3 %. Interestingly, we found that the luminescence intensity of hollow nanofibers is obviously greater than that of nanofibers and nanobelts for LaOBr:Tb3+ under the same measuring conditions. Moreover, the luminescence of LaOBr:Tb3+ nanostructures are located in the green region in Commission Internationale de L'Eclairage chromaticity coordinates diagram. The formation mechanisms of LaOBr:Tb3+ nanofibers, nanobelts, and hollow nanofibers were also proposed. LaOBr:Tb3+ nanostructures are promising nanomaterials for applications in the fields of light display systems and optoelectronic devices.