Characteristics of InGaN/AlN heterostructure grown by using MOCVD technique

The tuneable wide direct bandgap (covering a broad range of spectral regions) of III-nitride semiconductors, particularly indium gallium nitride (InGaN), has credited this material as a promising candidate for optoelectronic devices such as solar cells and photodetectors with the ability to have a selective or narrow response. However, developing such a device is not a straightforward process due to phase separation and composition inhomogeneity in InGaN ternary alloy. Thus, it is crucial to rigorously optimise the growth process and carry out an in-depth characterisation to suppress defect formation and obtain a high-quality InGaN active layer, which is suitable for the subsequent device fabrication process. In this work, a series of InxGa1-xN epilayers were epitaxially grown over a commercial 2" AlN/sapphire template using Taiyo Nippon Sanso Corporation (TNSC) metal-organic chemical vapour deposition (MOCVD) system. Then, to study the effect of the indium incorporation process and the correlation with its physical properties, the InxGa1-xN epilayers were grown at a different temperature setting from 860°C to 820°C. The structural, morphology and optical properties of the grown structure were investigated using X-ray diffraction (XRD), atomic force microscopy (AFM) and ultraviolet-visible (UV-Vis) spectrophotometer, respectively.