Investigation of optics behind N719 dye in dye-sensitized solar cells by using molecular dynamics simulation

A molecular dynamics simulation based on density functional theory is used to study the mechanism for the regeneration of the cis-di(thiocyanato)-bis(2, 2´-bipyridyl-4-carboxylate 4´carboxylic acid)-ruthenium (II) sensitizing dye (N719) by I in acetonitrile. The regeneration process includes the formation of barrier-free complex of the oxidized dye with both I^- and I₂^-, and the dissociation of I₂^- and I₃^- from the reduced dye. In addition to this, simulations of the electrolyte electrode interface are also presented which suggests the role of solvent in lowering the recombination process through redox mediator, thereby favoring swift dye regeneration. The results are validated using FTIR-ATR (Fourier Transform Infra Red- Attenuated Total Reflection) spectra.