Electrodeposited PEDOT/Nafion as Catalytic Counter Electrodes for Cobalt and Copper Bipyridyl Redox Mediators in Dye-Sensitized Solar Cells

Edoardo Marchini; Michele Orlandi; Nicola Bazzanella; Rita Boaretto; Vito Cristino; Antonio Miotello; Stefano Caramori; Stefano Carli

doi:10.1021/acsomega.2c03229

Electrodeposited PEDOT/Nafion as Catalytic Counter Electrodes for Cobalt and Copper Bipyridyl Redox Mediators in Dye-Sensitized Solar Cells

ACS Omega. 2022 Aug 11;7(33):29181-29194. doi: 10.1021/acsomega.2c03229. eCollection 2022 Aug 23.

Authors

Edoardo Marchini¹, Michele Orlandi², Nicola Bazzanella², Rita Boaretto¹, Vito Cristino¹, Antonio Miotello², Stefano Caramori¹, Stefano Carli³

Affiliations

¹ Department of Chemical, Pharmaceutical and Agrarian Sciences, University of Ferrara, 44121 Ferrara, Italy.
² Department of Physics, University of Trento, Via Sommarive 14, 38123 Trento, Italy.
³ Department of Environmental and Prevention Sciences, University of Ferrara, 44121 Ferrara, Italy.

Abstract

PEDOT-based counter electrodes for dye-sensitized solar cells (DSSCs) are generally prepared by electrodeposition, which produces polymer films endowed with the best electrocatalytic properties. This translates in fast regeneration of the redox mediator, which allows the solar cell to sustain efficient photoconversion. The sustainable fabrication of DSSCs must consider the scaling up of the entire process, and when possible, it should avoid the use of large amounts of hazardous and/or inflammable chemicals, such as organic solvents for instance. This is why electrodeposition of PEDOT-based counter electrodes should preferably be carried out in aqueous media. In this study, PEDOT/Nafion was electrodeposited on FTO and comparatively evaluated as a catalytic material in DSSCs based on either cobalt or copper electrolytes. Our results show that the electrochemical response of PEDOT/Nafion toward Co(II/III-) or Cu(I/II)-based redox shuttles was comparable to that of PEDOT/ClO₄ and significantly superior to that of PEDOT/PSS. In addition, when tested for adhesion, PEDOT/Nafion films were more stable for delamination if compared to PEDOT/ClO₄, a feature that may prove beneficial in view of the long-term stability of solar devices.