Jump to main content
Jump to site search

Issue 9, 2011
Previous Article Next Article

Anion-correlated conduction band edge shifts and charge transfer kinetics in dye-sensitized solar cells with ionic liquid electrolytes

Author affiliations

Abstract

In solvent-free ionic liquid electrolytes for efficient dye-sensitized solar cells, iodide and non-iodide melts are ordinarily blended in order to attain a high dynamic fluidity and thereby meet a fast mass transport of electroactive species. This common tactic could bring forth a prominent impact of various anions on cell efficiency by altering photocurrent and/or photovoltage. Herein we report evident effects of the dicyanamideversustetracyanoborate anion on the energetics of titania conduction band edge and the kinetics of multi-channel charge-transfer reactions in cells employing a high absorption coefficient ruthenium sensitizer C106. A slightly shorter photoluminescence lifetime of C106 grafted on alumina is probed for the tetracyanoborate-based reference cell with respect to the dicyanamide counterpart. However, owing to a more favourable thermodynamic driving force of ∼90 meV, the tetracyanoborate anion prompts an almost 3-fold faster electron injection from the excited-state dye to titania than dicyanamide, leading to a higher charge separation yield, which is in good agreement with an almost indistinguishable ratio of external quantum efficiency enhancement in the whole spectral response region. Compared to tetracyanoborate, the presence of dicyanamide at the titania/electrolyte interface evokes a 27-fold smaller interfacial electron exchange rate (K) with triiodide, accounting for the open-circuit photovoltage variation observed in current–voltage measurements.

Graphical abstract: Anion-correlated conduction band edge shifts and charge transfer kinetics in dye-sensitized solar cells with ionic liquid electrolytes

Back to tab navigation

Supplementary files

Publication details

The article was received on 01 Dec 2010, accepted on 01 Dec 2010 and first published on 24 Dec 2010


Article type: Paper
DOI: 10.1039/C0CP02728F
Phys. Chem. Chem. Phys., 2011,13, 3788-3794

  •   Request permissions

    Anion-correlated conduction band edge shifts and charge transfer kinetics in dye-sensitized solar cells with ionic liquid electrolytes

    M. Zhang, J. Zhang, Y. Bai, Y. Wang, M. Su and P. Wang, Phys. Chem. Chem. Phys., 2011, 13, 3788
    DOI: 10.1039/C0CP02728F

Search articles by author

Spotlight

Advertisements