ABSTRACT
Since surface characteristics and functionalization determine the
overall properties of silicon nanocrystal (Si NC), this chapter will
highlight aspects that relate to the role of Si NC surfaces with
respect to quantum confinement. Specifically, this chapter will
focus on surface engineering approaches that rely on plasma-based
and surfactant-free processing of doped Si NCs in liquid media
by either pulsed ns-laser or direct current (DC)/radio frequency
(RF) microplasmas. These techniques share a common character-
istic whereby atmospheric pressure plasmas that are generated
and confined within or in contact with liquids are capable of
inducing nonequilibrium liquid chemistry to tune and stabilize
the optoelectronic properties of Si NCs. The modified surface
characteristics have allowed exploring the performance of Si NCs
in photovoltaics. In particular Si NCs were electronically coupled
with carbon and nanocarbon materials. Si NCs with engineered
surface characteristics enhancing the electronic interactions with
carbon nanomaterials, and at the same time serve as metal-free
catalysts for the growth of multiwalled carbon nanotubes (CNTs).
Entirely consisting of Si NC/nanocarbon solar cells represent an
environmentally friendly potential solution for the large-scale man-
ufacturing of energy-harvesting devices; here we therefore discuss
the feasibility of prototype solar cells that consist of Si NCs combined
with fullerenes or with semiconducting single-walled CNTs.
