X-ray characterization of wurtzite formation in GaAs nanowires

Krogstrup, P.*; Morten Hannibal, M.*; Hu, W.; Kozu, Miwa*; Nakata, Yuka*; Nygard, J.*; Takahashi, Masamitsu; Feidenhans'l, R.*

monitoring of the crystal structure formation during Ga-assisted GaAs nanowire growth on Si(111) substrates has been performed in a combined molecular beam epitaxy growth and X-ray characterization experiment. Under Ga rich conditions, we show that an increase in the V/III ratio increases the formation rate of the wurtzite structure. Moreover, the response time for changes in the structural phase formation to changes in the beam fluxes is observed to be much longer than predicted time scales of adatom kinetics and liquid diffusion. This suggests that the morphology of the growth interface plays the key role for the relative growth structure formation rates.