Study on terbium doped lanthanum oxybromide luminescent nanoribbons and nanofibers

Abstract

Terbium doped lanthanum oxybromide (LaOBr:Tb3+) nanoribbons and nanofibers were successfully synthesized by double-crucible bromination of the electrospinning-derived La2O3:Tb3+ nanoribbons and nanofibers using NH4Br powders as the bromine source. The structure and morphology of the samples were investigated by X-ray diffractometry and scanning electron microscopy. The results indicated that LaOBr:Tb3+ nanoribbons and nanofibers were pure tetragonal in structure with space group of P4/nmm. The width of LaOBr:Tb3+ nanoribbons were 2.33 ± 0.33 μm and the diameter of LaOBr:Tb3+ nanofibers was 90.08 ± 15.19 nm. The photoluminescent properties of LaOBr:Tb3+ nanoribbons and nanofibers were also characterized systematically. Under the excitation of 253-nm ultraviolet light, LaOBr:Tb3+ nanostructures exhibit the green emission of predominant peak at 543 nm. The optimum doping molar concentration of Tb3+ ions in the LaOBr:Tb3+ nanoribbons is 5 %. Interestingly, the luminescence intensity of LaOBr:5 %Tb3+ nanofibers is obviously greater than that of LaOBr:5 %Tb3+ nanoribbons under the same measuring conditions. Moreover, the luminescence colors of LaOBr:Tb3+ nanostructures are located in the green region in Commission Internationale de L’Eclairage chromaticity coordinates diagram. The mechanism of double-crucible bromination method was also proposed. This new bromination technique not only can inherit the morphology of rare earth oxides precursor, but also can be used to fabricate pure-phase rare earth oxybromide at low temperature compared with conventional high temperature solid state bromination reaction method. LaOBr:Tb3+ nanostructures are promising nanomaterials for applications in the fields of light display systems and optoelectronic devices.