Study of Self-Induced Growth of AlGaAs Nanoneedles on Silicon Substrates Using Metal Organic Chemical Vapor Deposition Technique

A simple catalyst free growth method was used for the growth of single crystalline AlGaAs nanoneedles on Si substrate by metal organic chemical vapor deposition (MOCVD) technique. The growth mechanism of catalyst free growth of nanoneedles was investigated. The effect of growth rate, growth temperature and V/III ratio was studied in detail. The growth of nanoneedles required a careful optimization of the growth conditions. The formation of well-faceted nanoneedles with hexagonal cross-section was found to be influenced by the growth parameters. Based on these studies, the growth mechanism has been explained using nucleation theory. The growth of nanoneedles was believed to proceed via Vapor-Solid (VS) growth mechanism after the initial AlGaAs cluster formation depending on the growth conditions.

Growth of aluminum catalyzed AlGaAs nanowires on silicon substrate

Aluminum catalyzed AlGaAs nanowires were fabricated on Si (111) substrates using metal-organic chemical vapor deposition (MOCVD) technique at a low growth temperature of 450 degrees C. Grown structures were characterized by field emission scanning electron microscope (FE-SEM), energy-dispersive X-ray spectroscopy (EDS) and photoluminescence (PL) techniques. Nanowire clusters were observed all over the substrate. Multiprong root-grown AlGaAs nanowire clusters as well as catalyst particle terminated growth was observed. The growth is explained by Vapor-Solid-Solid (VSS) and Vapor-Solid (VS) growth mechanisms using Al-Si binary phase diagram. EDS and PL measurement confirm the formation of AlGaAs nanowires.