Rapid Dye Regeneration Mechanism of Dye-Sensitized Solar Cells.

Abstract

During the light-harvesting process of dye-sensitized solar cells (DSSCs), the hole localized on the dye after the charge separation yields an oxidized dye, D(+). The fast regeneration of D(+) using the redox pair (typically the I(-)/I3(-) couple) is critical for the efficient DSSCs. However, the kinetic processes of dye regeneration remain uncertain, still promoting vigorous debates. Here, we use molecular dynamics simulations to determine that the inner-sphere electron-transfer pathway provides a rapid dye regeneration route of ∼4 ps, where penetration of I(-) next to D(+) enables an immediate electron transfer, forming a kinetic barrier. This explains the recently reported ultrafast dye regeneration rate of a few picoseconds determined experimentally. We expect that our MD based comprehensive understanding of the dye regeneration mechanism will provide a helpful guideline in designing TiO2-dye-electrolyte interfacial systems for better performing DSSCs.

DOI: 10.1021/jz502197b

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Cite this paper

@article{Jeon2014RapidDR, title={Rapid Dye Regeneration Mechanism of Dye-Sensitized Solar Cells.}, author={Jiwon Jeon and Young Choon Park and Sang Soo Han and William A. Goddard and Yoon Sup Lee and Hyungjun Kim}, journal={The journal of physical chemistry letters}, year={2014}, volume={5 24}, pages={4285-90} }