Effects of growth temperature on nonpolar a‐plane InN grown by molecular beam epitaxy

Abstract

AbstractNonpolar a‐plane InN films were grown on r‐plane sapphire substrate by plasma assisted molecular beam epitaxy with GaN underlayer. Effect of growth temperature on structural, morphological, and optical properties has been studied. The growth of nonpolar a‐plane (1 1 ‐2 0) orientation was confirmed by high resolution X‐ray diffraction study. The film grown at 500 °C shows better crystallinity with the rocking curve FWHM 0.67° and 0.85° along [0 0 0 1] and [1 ‐1 0 0] directions, respectively. Scanning electron micrograph shows formation of Indium droplets at higher growth temperature. Room tem‐perature absorption spectra show growth temperature dependent band gap variation from 0.74–0.81 eV, consistent with the expected Burstein–Moss effect. The rectifying behaviour of the I–V curve indicates the existence of Schottky barrier at the InN and GaN interface. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)