B-doping of vapour-liquid-solid grown Au-catalysed and Al-catalysed Si nanowires: effects of B2H6 gas during Si nanowire growth and B-doping by a post-synthesis in situ plasma process

In this study, B-doping of vapour–liquid–solid (VLS) grown Si nanowires was studied. First, the different effects of B2H6 gas on nanowire structures during VLS growth of both Au-catalysed and Al-catalysed Si nanowires were investigated. While Au-catalysed Si nanowires grown with B2H6 gas reveal significant morphological changes, resulting in cone-shaped nanowires, structures comparable to un-doped nanowires were observed from Al-catalysed Si nanowires, which may be explained by thermodynamic properties of Au and Al catalyst in the presence of boron. In addition, successful incorporation of boron and controllability of its concentration in Si nanowires, maintaining the structural quality of the nanowires, was achieved by a post-synthesis in situ plasma B2H6 doping process.