Electrolyte effects on electron transport and recombination at ZnO nanorods for dye-sensitized solar cells

Yu Xie, Prakash Joshi, Seth B. Darling, Qiliang Chen, Ting Zhang, David Galipeau, Qiquan Qiao

Research output: Contribution to journalArticlepeer-review

67 Scopus citations

Abstract

Electrolyte effects on electron transport and recombination at ZnO nanorods (nd-ZnO) were studied by electrochemical impedance spectroscopy (EIS) in dye-sensitized solar cells (DSSCs). Different electrolyte systems were prepared by gradually adding tert-butylpyridine (TBP) and guanidinium thiocyanate (GuSCN) and replacing LiI with 1-butyl-3-methylimidazolium iodide (BMII). The introduction of TBP and GuSCN, and the replacement of LiI with BMII suppressed charge recombination at the nd-ZnO/electrolyte interface, increased electron lifetime (τn), improved electron transport, and reduced collection time (τd) on nd-ZnO. In addition, they improved the electron diffusion coefficient (Dn) and elongated the effective diffusion length (Ln). The electron transfer coefficient (β) at the ZnO/electrolyte interface was increased from 0.34 to 0.44, which was a good sign of improvement in fill factor (FF). In addition, the ohmic series resistance was reduced from 17.35 to 4.99 Ω•cm2 and the charge transfer resistance was decreased from 18.49 to 7.09 Ω•cm 2 at the electrolyte/Pt interface. Nd-ZnO DSSCs using different electrolytes were tested and the improvement of open circuit voltage (V oc), short circuit current density (Jsc), fill factor (FF), and incident photon to electron conversion efficiency (IPCE) was in good agreement with the findings from the EIS data.

Original languageEnglish (US)
Pages (from-to)17880-17888
Number of pages9
JournalJournal of Physical Chemistry C
Volume114
Issue number41
DOIs
StatePublished - Oct 21 2010
Externally publishedYes

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Energy(all)
  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films

Fingerprint

Dive into the research topics of 'Electrolyte effects on electron transport and recombination at ZnO nanorods for dye-sensitized solar cells'. Together they form a unique fingerprint.

Cite this