Synthesis and Properties of InGaN/GaN Multiple Quantum Well Nanowires on Si (111) by Molecular Beam Epitaxy

Herein, InGaN/GaN multiple quantum well (MQW) nanowire ensembles grown on Si (111) substrates by plasma-assisted molecular beam epitaxy (PA-MBE) are investigated. Well-oriented InGaN/GaN nanowires with perfect wurtzite crystal structure can be achieved by optimizing the growth parameter of bottom GaN nanowires. The morphology of the nanowires is strongly influenced by the AlN seeding layer growth time as well as the Ga/N flux ratio and by introducing excessive In flux and relatively higher quantum barrier (QB) growth temperatures. Strong emission from InGaN/GaN nanowires can be achieved by varying InGaN growth temperatures to change the incorporation of indium, therefore tuning the emission spectra from violet to amber. The observations from transmission electron microscopy (TEM) and energy dispersive spectrometer (EDS) mapping prove the high quality of MQWs with sharp interfaces and the uniform indium distribution in InGaN QWs.