Sn-filled Si nanotubes fabricated by the facile DC arc discharge method and their photoluminescence property

High-yield preparation of polycrystalline Si nanotubes (SiNTs) filled with single-crystal Sn was achieved by the DC arc discharge method. The Sn/Si nanocables were identified by X-ray diffraction (XRD), field-emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM) and photoluminescence (PL). The results show that the Sn/Si coaxial nanocables have homogeneous diameters of about 20–30 nm and lengths ranging from several ten to several hundred nanometers. Most of them are composed of an oval-shaped tip and a tapered hollow body. The possible growth mechanism is vapor–liquid–solid (VLS) model. The PL spectrum shows two characteristic emissions at 491 nm (blue emission) and 572 nm (yellow emission). The origin of luminescence was also discussed.