Crystal growth of Si nanowires and formation of longitudinal planar defects

Si nanowires were fabricated using Au nanoparticles as catalyst, either templated by porous anodic aluminium oxide films or on a smooth substrate of Si(100). The growth orientation of the nanowires and longitudinal planar defects such as twin defects and stacking faults were investigated using HRTEM. It was proposed that the nanowire growth was thermodynamically controlled with a slow growth rate and the growth orientation was normally the [111] zone axis of the cubic Si. When the growth rate was fast, the nanowire growth was kinetically controlled, leading to a growth orientation along the [112] zone axis. The formation mechanisms of various defects, such as twin defects, stacking faults and antiphase boundaries, are discussed.