Redox Reaction Mechanisms with Non-triiodide Mediators in Dye-Sensitized Solar Cells by Redox Potential Calculations

Ryota Jono; Masato Sumita; Yoshitaka Tateyama; Koichi Yamashita

doi:10.1021/jz301589a

Redox Reaction Mechanisms with Non-triiodide Mediators in Dye-Sensitized Solar Cells by Redox Potential Calculations

J Phys Chem Lett. 2012 Dec 6;3(23):3581-4. doi: 10.1021/jz301589a. Epub 2012 Nov 26.

Authors

Ryota Jono¹, Masato Sumita^{2

3}, Yoshitaka Tateyama^{2

3

4}, Koichi Yamashita¹

Affiliations

¹ †Department of Chemical System Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
² ‡International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
³ §CREST, Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama 333-0012, Japan.
⁴ ∥PRESTO, Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama 333-0012, Japan.

PMID: 26290992
DOI: 10.1021/jz301589a

Abstract

We investigate reaction mechanisms of the redox mediators in dye-sensitized solar cells through systematic calculations of redox potentials of possible cobalt complexes and iodides in acetonitrile solution by use of the thermodynamic cycle method with continuum solvent model. The calculated redox potentials were in good agreement with the experimental values, although the experimentalists used different reference electrodes. The maximum open circuit voltage (VOC) of the mediators calculated in this work indicate that the I2(•-)/2I(-) and I2/I2(•-) as well as the net I2/2I(-) redox reactions can dominate at both photoanode and counter-electrode.

Keywords: cathode; cobalt pyridine complex; counter electrode; iodide mediator; open circuit photovoltage; photoanode; redox potential.