Structural and transport properties of InN grown on GaN by MBE

In this work, the growth of InN on GaN substrates by molecular beam epitaxy and the structural and electrical characterization are presented. The quality of InN is found to be a sensitive function of the III/V flux ratio and the substrate temperature. The structural quality of InN is characterized by X-ray diffraction, and the transport property is characterized by Hall effect measurements. An optimum growth window to obtain high structural quality InN with high electron mobility is observed. A strong correlation between the structural quality and the measured Hall mobility is shown. Transmission electron microscope study of InN shows high dislocation density (∼ 2 ×1011 cm−2 at 200 nm from the InN/GaN interface), which is the limiting factor for the transport property in InN.