Synthesis of very long ErSi 2 nanowires on Si substrates

Abstract

ErSi 2 nanowires with a length of several micrometers have been fabricated on Si substrates. The starting samples were highly Er-doped amorphous Si thin layers formed by laser ablating an Si:Er 2O 3 mixture target. After post-annealing in vacuum, the nanowires were formed on the Si(0 0 1) surfaces along 〈 1 1 0 〉 directions. The average length and width of the wires depended on the annealing temperature and time. The height of the wires, in contrast, remained equal to be 0.6 nm. The longest wire achieved here was 20 μm. A large aspect ratio of 500 was obtained. X-ray diffraction and TEM observation indicated the hexagonal ErSi 2 formation. Our results provide a way to synthesize Si-based nanowires having enough length for further device applications without an UHV system.