Theoretical investigation of the excited states of coumarin dyes for dye-sensitized solar cells

Yuki Kurashige, Takahito Nakajima, Saki Kurashige, Kimihiko Hirao, Yoshinori Nishikitani

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151 Citations (Scopus)


Using time-dependent density functional theory (TD-DFT), configuration interaction single (CIS) method, and approximate coupled cluster singles and doubles (CC2) method, we investigated the absorption spectra of coumarin derivative dyes (C343, NKX-2388, NKX-2311, NKX-2586, and NKX-2677), which have been synthesized for efficient dye-sensitized solar cells. The CC2 calculations are found in good agreement with the experimental results except for the smallest coumarin dye (C343). TD-DFT underestimates the vertical excitation energy of the larger coumarin dyes (NKX-2586 and -2677). Solvents (methanol) are found to induce a red shift of the vertical excitation energies, and their effects on the molecular geometry and the electronic structure are examined in detail. The deprotonated form of coumarin is also investigated, where a blue shift of the vertical excitation energies is observed.

Original languageEnglish
Pages (from-to)5544-5548
Number of pages5
JournalJournal of Physical Chemistry A
Issue number25
Publication statusPublished - 2007 Jun 28
Externally publishedYes


ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

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