ABSTRACT
Following their inception in 1985,1-6 dye sensitized mesoscopic
solar cells (DSCs), also named Gra¨tzel cells after their inventor, have
emerged over the past two decades as non-conventional contenders
to p-n junction inorganic and photovoltaic (PV) devices. The DSC is
the only photovoltaic device that uses molecules to absorb photons
and convert them to electric charges without the need of excitonic
transport. It is also the only solar cell that separates the two
functions of light harvesting and charge carrier transport, whereas
conventional and all of the other known organic solar cell devices
perform both operations simultaneously. In this regard the DSC
mimics the primary process in the photosynthetic conversion of
solar energy by green plants where chlorophyll molecules absorb
sunlight, generating positive and negative charge carriers after
photo-excitation. The separation of light absorption and carrier
transport achieved by the DSC greatly increases the options for
the absorber and charge transport material allowing for attractive
new PV cell embodiments of different color and transparency. The
realization of light flexible forms is also possible.
