Semiconducting nanostructures are
considered among the most important building blocks in the field of
nanotechnology. Both their unique properties and potential applications as
building blocks for the development of a variety of electronic, photonic,
sensing, photovoltaic and energy storage devices have been investigated. In
particular, silicon nanowires have gained tremendous attention due to their
compatibility with current silicon-based microelectronics. This review
focuses on the description of the methods used to synthesize silicon nanowires
and the growth mechanisms involved in their synthesis using a range of systems
under different reaction conditions. The synthetic approaches to fabricate
silicon nanowires include bottom-up
and top-down techniques. Bottom-up approaches comprise several
different methods, such as chemical vapour deposition, laser ablation, thermal
evaporation, molecular beam epitaxy, solution-based routes and less conventional
techniques, such as electrodeposition and floating zone techniques. Top-down techniques can also be used to
produce silicon nanowires either horizontally or vertically located at certain
positions using nanolithography or micromachining processes. In addition, recent
theoretical models and calculations relating to the growth mechanisms are also
discussed.