This title appears in the Scientific Report : 2013 

Controlled wurtzite inclusions in self-catalyzed zinc blende III–V semiconductor nanowires
Rieger, Torsten (Corresponding author)
Lepsa, Mihail Ion / Schäpers, Thomas / Grützmacher, Detlev
Halbleiter-Nanoelektronik; PGI-9
JARA-FIT; JARA-FIT
Journal of crystal growth, 378 (2013) S. 506 - 510
Amsterdam [u.a.] Elsevier 2013
10.1016/j.jcrysgro.2012.12.035
Journal Article
Frontiers of charge based Electronics
Please use the identifier: http://dx.doi.org/10.1016/j.jcrysgro.2012.12.035 in citations.
The control of the Ga droplet during the MBE growth and its impact on the crystal structure of self-catalyzed GaAs nanowires (NWs) were investigated. The consumption of the droplet proceeds in two steps. First, the contact angle decreases to 90° keeping the NW diameter constant. The crystal structure changes from zinc blende (ZB) to wurtzite (WZ). Then, the contact angle keeps constant while the top radius of the NW decreases and the NW grows again in ZB configuration. During the last step, {110}, {211}B and {100} facets develop at the top. Calculations show that the Ga desorption from the droplet has to be taken into account during its consumption. With this information, several WZ segments of different lengths were placed into ZB GaAs NWs via partial droplet consumption. For this purpose, we supplied As and Ga separately, in order to partially consume and refill the Ga droplet. The same mechanism was applied to self-catalyzed InAs NWs resulting in short WZ segments inserted in a ZB twinning superlattice.