A systematic study on self-catalyzed growth of InAs/GaSb axial heterostructured nanowires by MOCVD

Traditional Au-catalyzed growth method of nanowires will mix Au atoms into Si substrates and InAs/GaSb axial heterojunction materials to introduce deep energy levels, which will seriously degrade the electrical and photoelectric properties of nanodevices. In this work, we studied in detail the effects of multiple growth parameters on self-catalyzed growth of InAs/GaSb axial heterostructured NWs on Si substrate by MOCVD. It is found that in the switching process from InAs material precursor to GaSb material precursor, if growth temperature of GaSb is not appropriate and switching time is too long, it will cause the decomposition and disappearance of InAs NWs, and directly terminate the realization of InAs/GaSb axial heterojunction NWs. Both the parameter windows of the growth temperature and V/III ratio are very narrow, which directly affects the growth trend of GaSb material in axial or radial deposition. It provides an important and meaningful method for self-catalyzed high-quality nanowires by MOCVD that up high pure GaSb nanowires requires the catalyzed guidance of alloy droplets and buffer seed nanowire and bottom InAs nanowires just meet both requirements.