Outer-sphere redox couples as shuttles in dye-sensitized solar cells. performance enhancement based on photoelectrode modification via atomic layer deposition

Thomas W. Hamann, Omar K. Farha, Joseph T Hupp

Research output: Contribution to journalArticle

144 Citations (Scopus)

Abstract

Atomic layer deposition (ALD) has been used to create conformal TiO 2 blocking layers on fluorine-doped tin-oxide substrates in dye-sensitized solar cells (DSSCs), effectively eliminating shunting. ALD has also been used to deposit, in controlled fashion, ultrathin coatings of alumina on nanoparticle-based TiO 2 DSSC photoanodes. These modified electrodes enable ferrocenium/ferrocene, an outer-sphere redox couple, to be used as a shuttle. The photovoltaic performance and interfacial charge-transfer dynamics were investigated in DSSCs employing this shuttle. It was found that a single ALD cycle is able to passivate surface states, resulting in a dramatic improvement in photovoltaic performance. Subsequent alumina deposition resulted in exponentially increasing electron lifetimes as a function of alumina layer thickness, indicating that the layers behave as barriers to electron tunneling. The characterization of DSSC photovoltaic performance and interfacial charge-transfer dynamics was extended to cells employing derivatives of ferrocenium and ferrocene featuring more positive redox potentials; these cells yielded larger open-circuit photovoltages.

Original languageEnglish
Pages (from-to)19756-19764
Number of pages9
JournalJournal of Physical Chemistry C
Volume112
Issue number49
DOIs
Publication statusPublished - Dec 11 2008

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Atomic layer deposition
atomic layer epitaxy
Aluminum Oxide
solar cells
dyes
Alumina
aluminum oxides
augmentation
Charge transfer
charge transfer
Electron tunneling
Fluorine
photovoltages
Surface states
electron tunneling
Tin oxides
cells
tin oxides
fluorine
Deposits

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Electronic, Optical and Magnetic Materials
  • Surfaces, Coatings and Films
  • Energy(all)

Cite this

Outer-sphere redox couples as shuttles in dye-sensitized solar cells. performance enhancement based on photoelectrode modification via atomic layer deposition. / Hamann, Thomas W.; Farha, Omar K.; Hupp, Joseph T.

In: Journal of Physical Chemistry C, Vol. 112, No. 49, 11.12.2008, p. 19756-19764.

Research output: Contribution to journalArticle

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