Source configuration dependent molecular beam epitaxy of AlN nanowires

Aluminum nitride (AlN) has emerged as a critical platform for advancing deep ultraviolet optoelectronics and high-power electronics due to its merits such as a wide bandgap and excellent thermal conductivity. This study explores the molecular beam epitaxy growth of self-organized AlN nanowires on Si (111) substrates, focusing on how the source configuration and substrate rotation affect the nanowire morphology, which is key to their device applications. Under stationary substrate conditions, AlN nanowires grown using two different Al source configurations exhibit similar features, with a highly irregular top surface. With substrate rotation, the top surface becomes more regular. Moreover, when the substrate is rotated, the nanowire morphology is significantly different comparing the samples using two different Al sources, and the sample with the Al source that is close to the nitrogen source is more uniform. The underlying mechanisms for these observations are also discussed.