Fabrication and Characterization of In/ZnO-SiOx Core-Shell Nanocable Heterostructures

Indium doped ZnO-SiOx core-shell nanocable heterostructures were successfully fabricated by introducing In ions into the raw material via a simple thermal evaporation process. X-ray diffraction (XRD), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDS) were used to investigate the structure of the In/ZnO-SiOx core-shell fibers. Results indicated that the core zone of ZnO nanocables is single crystalline In/ZnO with a wurtzite structure and the shell zone is a SiOx amorphous layer. The nanocables have high aspect ratio of more than 100 with widths of 30-60 nm. The growth mechanism of the nanocable heterostructures is different from the commonly reported metal-seeded vapor-liquid-solid (VLS) mechanism. The synthesis of core-shell structures reveals the general potential of radial heterostructure growth for the development of nanowire-based devices.