Epitaxial GaN Thin Films Prepared by Polymer-Assisted Deposition

Abstract

Epitaxial GaN thin films have been deposited on (0001) sapphire substrates by a chemical solution approach of polymer-assisted deposition. The films are smooth with no detectable cracks or pores, as observed by scanning electron microscopy and atomic force microscopy. Microstructural studies by X-ray diffraction and transmission electron microscopy show that the GaN films have a hexagonal structure with an epitaxial relationship between the film and the substrate of (0001)GaN||(0001)Al2O3 and [112̅0]GaN||[101̅0]Al2O3. The films with a room temperature resistivity of around 0.13 Ω·cm exhibit photoluminescence characteristic of wurtzite hexagonal GaN.