GaN nanowires grown on silicon substrates engraved using stainless-steel micro-tip

摘要

GaN nanostructures have been synthesized on silicon substrates using chemical vapor deposition. Prior to growth silicon substrates were engraved using stainless-steel micro-tips. Straight as well as twisted nanowires were observed along the engraved lines/regions. Straight nanowires were few tens of microns in length and the twisted ones were few microns in length with diameter variation between 30 nm and 100 nm. The electron microscopy analysis indicates that the nanowires were grown parallel to the c-axis and possible growth mechanism is described. Raman scattering indicates good quality of nanowires exhibiting intense E_2 (high) mode and A,(LO) mode and a huge red-shift in the mode position indicates nano-size effects. Such engraved substrates without any explicit catalyst can provide site controlled growth of nanowires and this methodology is extendable for growing nanowires of related materials.