Fabrication of GaN nanocone arrays on Si by pulsed laser ablation using Anodic Aluminum Oxide mask

Abstract

We demonstrate the fabrication of Gallium Nitride (GaN) nanocone arrays of different heights on Si by pulsed laser deposition using an Anodic Aluminum Oxide (AAO) as a mask. A highly self-ordered hexagonal array of cylindrical pores has been fabricated by anodizing a thin film of Al on substrate and subsequent growth of GaN into these nanoholes has been performed by pulsed laser ablation. Arrays of nanocones were examined under the field emission Scanning Electron Micros-copy (SEM). The height of these nanocones is also observed to be affected by the change in target to substrate distance and laser fluence. X-ray Photoelectron Spectrum (XPS) is obtained to confirm that these are GaN nanocones. X-ray diffraction (XRD) spectrum is also obtained to examine the crystal structure of these nanocones. In addition, a simple method to strip off the AAO template af-ter synthesis is also used. This technique of stripping off the template is hassle-free compared to the conventional wet-etching method. AAO template-based synthesis method provides a low cost proc-ess to fabricate GaN-based nanomaterials fabrication.