  Silicon, one of the most abundant elements found on Earth, has been an
excellent choice of the semiconductor industry for ages. Despite it's
remarkable applications in modern semiconductor-based electronic devices, the
potential of cubic silicon in superconducting electronics remained a challenge
because even heavily doped silicon crystals do not superconduct under normal
conditions. It is apparent that if superconductivity can be introduced in cubic
silicon, that will bring a breakthrough in low-dissipation electronic
circuitry. Motivated by this, attempts have been made by several research
groups to induce superconductivity in silicon through a number of different
routes. Some of the other structural phases of silicon like $\beta$-Sn and
simple hexagonal are, however, known to display superconductivity. In the
present review article, various theoretical and experimental aspects of
superconductivity in silicon are discussed. Superconductivity in different
phases and different structural forms of silicon are also reviewed. We also
highlight the potential of superconducting phases of silicon for technological
applications in super-conducting nano-electronics.
