On the non-monotonic lateral size dependence of the height of GaAs nanowhiskers grown by molecular beam epitaxy at high temperature

GaAs nanowhiskers were grown by molecular beam epitaxy on the GaAs(111)B surface activated by Au at the surface temperature of 585 °C. The dependence of nanowhisker height on the size of Au-GaAs alloy drops was investigated. It has been found that the height of GaAs nanowhiskers is zero at a certain minimum diameter of drop, then increases with size, has a pronounced maximum at a certain size, decreases for thicker whiskers and finally goes to a certain asymptotic value. The theoretical model for the growth kinetics of nanowhiskers was developed in order to explain the observed size dependence. The results of comparison of theoretical and experimental data for the height of GaAs nanowhiskers are presented and analyzed.