Semipolar and polar (0001) InGaN grown on sapphire substrate by using pulsed metal organic chemical vapor deposition**Project supported by the National Natural Science Foundation of China (Grant Nos. 61204006 and 61574108) and the Fundamental Research Funds for the Central Universities, China (Grant No. 7214570101).

Abstract

High indium semipolar and polar (0001) InGaN layers each with a thickness of about 100 nm are realized simultaneously on sapphire substrates by pulsed metal organic chemical vapor deposition (MOCVD). The morphology evolution, structural and optical characteristics are also studied. The indium content in the layer of the surface is larger than that of the surface (0001), which is confirmed by reciprocal space map, photoluminescence spectrum and secondary ion mass spectrometer. Additionally, the (0001) surface with island-like morphology shows inhomogeneous indium incorporation, while the surface with a spiral-like morphology shows a better homogeneous In composition. This feature is also demonstrated by the monochromatic cathodoluminescence map.