Japanese Journal of Applied Physics · 2013 · 13 citations · 18 references
EngineeringMaterials EngineeringMaterials ScienceElectronic MaterialsNanotechnologySemiconductor MaterialsDislocations In SemiconductorsNanostructured Electronic MaterialsSemiconductor Crystal GrowthSemiconductor Device MaterialsSemiconductor NanomaterialsWide-bandgap SemiconductorsCoalescenceCrystal Quality ControlDislocation DensityDislocation NetworksGallium NitrideGallium Nitride (Gan) MaterialsGallium Nitride Crystal GrowthOptical Properties
(112̄2) semi-polar GaN with significantly improved crystal quality has been achieved by means of overgrowth on a (112̄2) semi-polar nanorod template. The nanorod template was fabricated on a standard (112̄2) semi-polar GaN layer on m -plane sapphire using a self-organized nickel nano-mask technique. In comparison with any conventional overgrowth technique, the nano-mask approach has demonstrated a very quick coalescence with a thickness of less than 1 µm. X-ray rocking curve measurements as a function of azimuth angle has shown a massive reduction in linewidth for our overgrown GaN. Transmission electron microscope measurements have confirmed a significant reduction in the dislocation density. Dramatic improvement in optical properties has been exhibited by photoluminescence (PL) measurements performed at room temperature, showing that the PL intensity from the band edge emission is 30 times higher than that of the standard semi-polar GaN on sapphire.
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