Dual-function smart electrolyte for dye-sensitized solar cells: 5-mercaptotetrazoles as redox mediator and corrosion repressor

Rishabh Bhargava, Torben Daeneke, Simon J. Thompson, Julian Lloyd, Carlos-Andres Palma, Joachim Reichert, Johannes V. Barth, Leone Spiccia, Udo Bach

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12 Citations (Scopus)


Metal charge collectors are an essential component of photovoltaic
modules, facilitating charge collection over larger areas. Their application in dyesensitized solar cells has so far been hampered by two major factors: (1) the redox mediators employed in these photoelectrochemical devices are generally corrosive to metals, and (2) they generally show low overpotentials for their redox reactions on these metal surfaces, which leads to significant recombination losses at the photoanode. Here, a thiolate-based redox mediator, sodium 1-phenyl-1H-5-mercaptotetrazole (Tph), is shown to form self-assembled monolayers on silver electrodes and to act as an effective corrosion protection layer while also exhibiting high overpotentials on these metals at the photoanode. The anticorrosive properties are strongly dependent on the structure of the thiolate. Replacement of the phenyl group in Tph with a methyl substituent accelerates the corrosion process by orders of magnitude. Finally, we demonstrate the applicability of Tph-based electrolytes in a 60 cm2 dye-sensitized solar cell comprising unprotected silver charge-collecting electrodes.
Original languageEnglish
Pages (from-to)19613 - 19618
Number of pages6
JournalJournal of Physical Chemistry C
Issue number34
Publication statusPublished - 2015

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