2019/12/13 by Thomas Dursap, T. Dursap, Dursap, T. +18
Engineering · Materials Science · Physics and Astronomy · #Chalcogenide Semiconductor Thin Films #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Nanowire Synthesis and Applications #Quantum Dots Synthesis And Properties #cond-mat.mtrl-sci
paper · pdf · doi:10.48550/arxiv.1912.06502
21 pages, 7 figures
arxiv created 2019/12/13 · openalex publication_date 2019/12/13 · arxiv updated 2019/12/16 · openalex created_date 2019/12/26 · openalex updated_date 2026/07/28
It is well known that the crystalline structure of the III-V nanowires (NWs) is mainly controlled by the wetting contact angle of the catalyst droplet which can be tuned by the III and V flux. In this work we present a method to control the wurtzite (WZ) or zinc-blende (ZB) structure in self-catalyzed GaAs NWs grown by molecular beam epitaxy, using in situ reflection high energy electron diffraction (RHEED) diagram analysis. Since the diffraction patterns of the ZB and WZ structures differ according to the azimuth [1-10], it is possible to follow the evolution of the intensity of specific ZB and WZ diffraction spots during the NW growth as a function of the growth parameters such as the Ga flux. By analyzing the evolution of the WZ and ZB spot intensities during some NW growths with specific changes of Ga flux, it is then possible to control the crystal structure of the NWs. ZB GaAs NWs with a controlled WZ segment have thus been realized. Using a semi-empirical model for the NW growth and our in situ RHEED measurements, the critical wetting angle of the catalyst droplet for the structural transition is deduced.