Polymer based photovoltaic cells are being intensively investigated. In such
cells three key processes need to occur; namely light absorption, charge separation of
the exciton, and transport of the separated charges to the electrodes. Light absorption
is reliant on the optical density of the polymer. In general charge separation is
achieved by blending an electron acceptor with the polymer film. However, blending
materials gives rise to potentially unreliable manufacturing and lifetime issues. This
thesis describes the preparation of poly(l,4-phenylenevinylene) derivatives containing
dipoles in which the process of charge separation can be achieved intramolecularly.
The dipole was created with the use of electron donating alkoxy groups attached to
the polymer backbone, and electron withdrawing nitro group attached to the fluorenyl
side chains. These groups are believed to facilitate the dissociation of the
photogenerated exciton, and potentially stabilise the holes and electrons that are
formed when the exciton is separated. The fluorenyl side chains were attached to the
polymer backbone via biphenyl or vinyl linkages. The polymers were primarily
formed using the Gilch method and the conjugated polymers were obtained either via
a soluble precursor route or directly from the monomer. The photophysical properties
were studied for polymers with the fluorenyl side-chains as they were found to be
more easily formed and stable. For poly[2-(7-nitro-9,9-dipropylfluorenyl)-5-(2'-
ethylhexyloxy)-l,4-phenylenevinylene] it was found that the photoluminescence
quantum yield dropped by a factor of eight relative to the polymer without the nitro
group. It was further elucidated that this was due to the exciton being separated. Solar
cells containing the polymers from this study showed modest performance