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Abstract: In this paper, we report the studies on the hetero-epitaxial growth of wurtzite indium nitride (InN) thin films on oxide buffer layer by RF metal-organic molecular beam epitaxy (RF-MOMBE) system. Oxide buffer layer was pre-sputtered using RF sputtering technique. The structural properties and surface morphology were investigated by X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). We also investigated the optical properties by temperature-dependence photoluminescence (PL). Near-infrared emission peak centered at 0.75eV was observed from PL measurement. The irregular and asymmetric PL line shape was caused by absorbed moisture and surface electron accumulation in InN films. According to the fitting results of PL spectra measured at 20K, we could estimate the bandgap and Fermi level is 0.65eV and 113meV, which confirm to previous reports. Our results reveal that the oxide thin film could be a suitable buffer layer for engineering the growth of InN on sapphire wafer, and it might be also applicable for other lattice-mismatched III-V hetero-epitaxial systems. [Copyright &y& Elsevier]

Abstract: GaN-based light-emitting diodes (LEDs) with naturally textured surfaces were grown by metal-organic chemical vapor deposition (MOCVD). A naturally textured p-GaN surface layer was fabricated by controlling the growth temperature. The output power of light from the naturally textured surface GaN-based LED, whose p-GaN layer was grown at 850°C, was 48.6% higher than that from a commercial GaN-based LED. The GaN-based LED with a naturally textured surface and a thick p-GaN layer with a thickness of 300nm, which was grown at a high growth temperature, exhibited improved electrostatic discharge (ESD) resistance and could resist a reverse bias voltage of as high as 3500V. The experimental results demonstrate that the naturally textured growth method combined with a p-GaN layer grown at high temperature is suitable for manufacturing high-efficient low-cost GaN-based LEDs. [Copyright &y& Elsevier]