An atomistic picture of the regeneration process in dye sensitized solar cells.
P NATL ACAD SCI USA
4830 - 4833.
A highly efficient mechanism for the regeneration of the cis-bis(isothiocyanato) bis(2,2'-bipyridyl-4,4'-dicarboxylato)-ruthenium (II) sensitizing dye (N3) by I- in acetonitrile has been identified by using molecular dynamics simulation based on density functional theory. Barrier-free complex formation of the oxidized dye with both I- and I-2(-), and facile dissociation of I-2(-) and I-3(-) from the reduced dye are key steps in this process. In situ vibrational spectroscopy confirms the reversible binding of I-2 to the thiocyanate group. Additionally, simulations of the electrolyte near the interface suggest that acetonitrile is able to cover the (101) surface of anatase with a passivating layer that inhibits direct contact of the redox mediator with the oxide, and that the solvent structure specifically enhances the concentration of I- at a distance which further favors rapid dye regeneration.
|Title:||An atomistic picture of the regeneration process in dye sensitized solar cells|
|Keywords:||density functional theory, molecular dynamics simulations, photovoltaics, solid/liquid interfaces, statistical mechanics, NANOCRYSTALLINE TIO2, MOLECULAR-DYNAMICS, ELECTRON-TRANSFER, PSEUDOPOTENTIALS, SIMULATIONS, EXCHANGE, DENSITY, ION|
|UCL classification:||UCL > School of BEAMS > Faculty of Maths and Physical Sciences > Chemistry|
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