MoSe2 nanosheet/poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) composite film as a Pt-free counter electrode for dye-sensitized solar cells

Yi June Huang, Miao Syuan Fan, Chun Ting Li, Chuan Pei Lee, Tai Ying Chen, R. Vittal, Kuo Chuan Ho*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

30 Citations (Scopus)

Abstract

A composite film of molybdenum diselenide nanosheets and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (MoSe2 NS/PEDOT:PSS) was prepared for the counter electrode (CE) of a dye-sensitized solar cell (DSSC), via a low-cost drop-coating method. The two-dimensional (2D) nanosheets of MoSe2 (MoSe2 NS) were aimed to provide the composite film not only a large amount of electrocatalytic active sites but also orientational pathways for electron transfer, from the conducting substrate of the CE to the interface at the CE electrolyte. The PEDOT:PSS acts as the conductive matrix for the composite film, and also enables multiple interfacial electron transfer pathways between the MoSe2 NS and the substrate. Owing to the combination of the advantages of both MoSe2 NS and PEDOT:PSS, the DSSC with the composite film of MoSe2 NS/PEDOT:PSS on its CE exhibited a power conversion efficiency (η) of 7.58 ± 0.05%, which is comparable to that of the cell with a Pt CE (7.81 ± 0.03%). The counter electrode films were characterized by scanning electron microscopy. Various electrochemical analyses, including those with cyclic voltammetry, rotating disk electrode, Tafel polarization curves, and electrochemical impedance spectroscopy, were performed intending to quantify the electrocatalytic ability of the counter electrode films; these techniques were able to precisely distinguish the functions of MoSe2 NS and PEDOT:PSS in the composite films; the former worked as an electrocatalyst and the latter as a conductive binder. Incident photon-to-current conversion efficiency (IPCE) was used to substantiate the photovoltaic parameters. When the MoSe2 NS/PEDOT:PSS composite film was coated on a flexible titanium (Ti) foil, the pertinent DSSC showed even a higher η of 8.51 ± 0.05%, as compared to a lower η of 8.21 ± 0.02% using the Pt-coated Ti foil CE. The results indicate the promising potential of MoSe2 NS/PEDOT:PSS composite film to replace the expensive Pt.

Original languageEnglish
Pages (from-to)794-803
Number of pages10
JournalElectrochimica Acta
Volume211
DOIs
Publication statusPublished - 2016 Sep 1
Externally publishedYes

Keywords

  • Counter electrode
  • Dye-sensitized solar cell
  • Flexible titanium foil
  • Molybdenum diselenide nanosheets
  • MoSe
  • PEDOT:PSS
  • Rotating disk electrode

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Electrochemistry

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