Structures and energetics of indium-catalyzed silicon nanowires

Strong size dependent structures of Si nanowires, grown via indium nanoparticles, have been revealed by high-resolution transmission electron microscopy studies. It is found that, below the critical value of particle diameter of approximately 100 nm, the growth changes from 111 to predominantly 211 direction and the formation of multiple {111} twins changes from perpendicular to the 111 growth direction to parallel to the 211 axial direction. The growth mechanisms are discussed in terms of relative surface/interface energy, using Au catalyzed Si nanowires as a comparative benchmark.