Focused ion beam implantation for the nucleation of self-catalyzed III-V nanowires

Abstract

Focused ion beam implantation was used for the formation of Ga droplets which act as nucleation points for self-catalyzed, molecular beam epitaxy-grown nanowires on Si(111). In order to further optimize the growth, the substrate after implantation was analyzed via atomic force microscopy, which indicated that sputtering depth had a strong influence on the subsequent nanowire growth. Lower beam voltage accelerations led to beam defocusing and thereafter better growth, while focused, high-acceleration beams led to a larger sputtering depth, worse growth and more tilted nanowire growth. The optical quality of the nanowires was evaluated using spatially resolved photoluminesence measurements at room temperature.