Single-crystalline GaN nanotube arrays grown on c-Al2O3 substrates using InN nanorods as templates

Abstract

Single-crystalline GaN nanotube arrays were grown on c-Al2O3 substrates by metal-organic chemical vapor deposition. InN nanorods with In droplets at the top-ends were used as the templates. After growing GaN over the templates, InN nanorods were thermally removed and GaN nanotubes were obtained. In droplets were considered to be the pathways for the decomposed InN species to escape away and played an important role in the formation of GaN nanotubes. The nanotubes are well-aligned along the c-axis of the wurtzite GaN structure with good crystal quality and morphologies. X-ray diffraction and energy-dispersive X-ray spectrometer studies indicate that the products are absent of template related residues. Our method for fabricating GaN nanotubes can be applied to the formation of nanotube arrays of other materials (such as AlGaN and AlN).