Phase purification of GaAs nanowires by prolonging the growth duration in MBE

Abstract

In this study, we demonstrated that by merely prolonging the growth duration, the growth behavior and phase purity of GaAs nanowires can be manipulated in molecular beam epitaxy. Through careful morphological, structural and chemical characterization of the grown nanowires, it was found that in the group-III dominated regime, by increasing the growth duration, the Ga concentration in the catalysts increases due to the formation of nanowire shoulders, which provide sites for Ga diffusion towards the catalysts. This fact leads to the enhancement of the nanowire growth and improved phase purity. In particular, single-phase nanowire sections have been observed with prolonged nanowire growth duration. This study provides a new insight into the role of growth duration in III–V nanowire growth and a possible approach for nanowire phase purification, which is critical for nanowire applications.