Nanocrystalline gallium nitride thin films

Abstract
Nanocrystallinegallium nitride(GaN)thin films were deposited on quartz substrates by reactive rf sputtering of GaAs target with nitrogen as the reactive cum sputtering gas. X-ray diffraction and transmission electron microscopy confirmed the presence of GaN crystallites with particle size increasing from 3 to 16 nm, as the substrate temperature was increased from 400 to 550 °C. The particle size in films grown at temperatures below 550 °C were less than the exciton Bohr radius of GaN. The band gap of these films obtained from absorption and photoluminescence measurements showed a blueshift with respect to bulk GaN.