Construction and Up-conversion Luminescence of LaF3:Er3+ Nanofibers

Abstract

La2O3:Er³⁺ nanofibers were synthesized by sintering the electrospun $\text{PVP}/[\text{La}(\text{NO}_{3})_{3}+\text{Er}(\text{NO}_{3})_{3}]$ composite nanofibers, and LaF3: Er³⁺ nanofibers were successfully constructed by fluorination of the relevant electrospun La2O3: Er³⁺ nanofibers via bi-crucible method by using NH4HF2 as fluorine source. LaF3: Er³⁺ nanofibers possess superior fiber-like morphology. Upon 980-nm laser excitation, LaF3: Er³⁺ nanofibers emit green and red up-conversion emissions centering at 520, 538 and 649 nm, respectively. The green emissions come from the transitions of ${}^{2}\mathrm{H}_{11/2}/{}^{4}\mathrm{S}_{3/2}\rightarrow^{4}\mathrm{I}_{15/2}\ \text{of}\ \text{Er}^{3+}$ ions, and the red emission is arisen from the transition of ${}^{4}\mathrm{F}_{9/2\rightarrow}{}^{4}\mathrm{I}_{15/2}$ of Er³⁺ ions. The technology could be applied for fabrication of other rare-earth fluorides up-conversion nanofibers.