Structural and optical characterization of GaN grown on porous silicon substrate by MOVPE

GaN was grown on porous silicon (PS) substrates by Metalorganic Vapour Phase Epitaxy at temperature of 1050 8C. An additional AlN buffer layer is used between GaN and PS. The crystalline quality and surface morphology of GaN films were studied by X-ray diffraction and scanning electron microscope (SEM), respectively. Preferential growth of hexagonal GaN with h00.1i direction is observed and is clearly improved when the thickness of AlN buffer layer increases. Morphological changes in PS layer appearing after growth have been also discussed. GaN optical qualities were determined by photoluminescence at low and room temperature (RT). q 2004 Elsevier Ltd. All rights reserved.