Interaction of voids and nano-ductility in single crystal silicon

► Voids growth and interaction in single crystal silicon cubes are investigated. ► Two fracture behaviors are observed: brittle cleavage and ductile void coalescence. ► The brittle-ductile transition depends on initial inter-void ligament distance. ► Initial inter-void ligament distance increase with void radius increasing. ► Nano-ductility in single crystal Si is due to vacancies diffusion in the ligament.