Twin formation in nanowires (SiNWs) grown via the vapor–liquid–solid mechanism was investigated. It was found that the formation of twins in Si nanowires was predominantly affected by the nanowire diameter: they were formed only for nanowires with a diameter greater than a certain critical value, while single crystal nanowires could form when the diameter was smaller. Detailed observation revealed that, in nanowires grown in the [111] direction, which were the most commonly observed nanowires under current experimental conditions, periodic twins were formed while multiple twins were formed in the minor [110]-directed nanowires. The defect formation mechanism was also discussed for the purpose of better control of crystal perfection in Si nanowires.

Size-Dependent Structural Characterization of Silicon Nanowires. S.Akhtar, K.Usami, Y.Tsuchiya, H.Mizuta, S.Oda: Japanese Journal of Applied Physics, 2008, 47, 5053-6