The effect of chenodeoxycholic acid as the coadsorbent with a squaraine sensitizer on TiO(2) nanocrystalline solar cells was investigated, and it was found that the coadsorbent prevents the squaraine sensitizer from aggregating on the TiO(2) nanoparticles but reduces dye loading leading to an interdependent photovoltaic performance. Analysis of the absorption spectra, and incident monochromatic photon-to-current conversion efficiency data showed that the load of squaraine sensitizer as well as the appearance of H-aggregates is strongly dependent on the molar concentration of chenodeoxycholic acid coadsorbent. The open circuit voltage of the solar cells with chenodeoxycholic acid increases due to the enhanced electron lifetime in the TiO(2) nanoparticles coupled with the band edge shift of TiO(2) to negative potentials.
In this chapter we have introduced operating principles of dye-sensitized solar cells, molecular engineering aspect of sensitizers and redox mediators. The design strategies of ruthenium sensitizers consisting of polypyridyl ligands with, and without thiocyanate ligands are demonstrated. Organic sensitizers based on donor–π-spacer–acceptor (D-π-A) architecture, in which electron-rich (donor) and electron-poor (acceptor) are connected through a conjugated (π) bridge and the anchoring group is attached with the acceptor part, donor–chromophore–acceptor family diketopyrrolopyrrole (DPP) and ullazine sensitizers and their photovoltaic properties are discussed. Molecular engineering aspect of porphyrin core with the bulky donor and strong acceptor groups to obtain panchromatic response is shown. In the last section we highlighted organic–inorganic hybrid perovskites for thin-film photovoltaics, which came to the limelight because of their high efficiency, low cost and the ease to make these materials solution processable yielding over 15% efficiency.
Two charged organometallic complexes containing bulky hydrophobic ligands based on ruthenium (II) and iridium (III) were synthesized and their performance in solid state light emitting electrochemical cells is described. The complexes were chosen as due to their large ligands a diminished susceptibility towards the formation of destructive complexes during device operation is expected. The LEC device performances reveal the longest living devices reported so far under dc bias. Quantum chemical calculations confirm that the major effect of the bulky diphenylphenanthroline ligands is of steric origin and not related with changes in the molecular electronic structure of the complexes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.