New growth mechanism of InAs-GaSb core-shell nanowires with polygonal triangular pyramids and quantum dots grown by MOCVD

In this paper, new growth mechanism of InAs/GaSb heterojunction nanowires grown by MOCVD has been investigated. A spear -shaped structure was firstly formed at the top of nanowires and GaAsSb quantum dots were firstly grown on the side walls of the nanowires by self -catalyzed mode. It is found that the length of InAs-GaSb nanowires in core -shell structure plays an important role in the formation of polygonal triangular pyramids and quantum dots structures. The shorter InAs nanowires become, the larger the polygonal triangular pyramid will be formed while the longer InAs nanowires become, the smaller the polygonal triangular pyramid will be formed, and quantum dots will appear on the side walls of nanowires. This new mechanism and growth technology will be conducive to the preparation of quantum dots attached to the surface of nanowires.