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

La
2
O
3
:Er
³⁺
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: Er
³⁺
nanofibers were successfully constructed by fluorination of the relevant electrospun La
2
O
3
: Er
³⁺
nanofibers via bi-crucible method by using NH
4
HF
2
as fluorine source. LaF
3
: Er
³⁺
nanofibers possess superior fiber-like morphology. Upon 980-nm laser excitation, LaF3: Er
³⁺
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 Er
³⁺
ions. The technology could be applied for fabrication of other rare-earth fluorides up-conversion nanofibers.