Microstructural and photoluminescent properties of terbium-doped SiC nanotubes prepared by sputtering using electrospun polymer templates

Terbium-doped SiC (SiC:Tb) nanotubes were prepared by sputtering using electrospun PVP nanofiber templates, followed by annealing in air and carbothermal reduction. Results showed that the obtained SiC:Tb nanotubes are 100-200 nm in outer diameter and 20-50 nm in wall thickness. Photoluminescence (PL) tests indicated that the as-obtained amorphous SiC:Tb nanotubes exhibited a rather low PL from the doped Tb3+ ions, but a strong self-active PL of Si-C-O defects. While the carbothermal treatments at 800 or 900 °C can greatly enhance the Tb-related PL, further increasing the calcination temperature to 1200 °C will force most of the Tb ions to separate out to the surface of the nanotubes, which is mainly responsible for the second increase in the Tb-related PL.