Anomalous rheological behavior in chemically modified TiO2 colloidal pastes prepared for flexible dye-sensitized solar cells

Hasitha C. Weerasinghe, George V. Franks, Johan D. Plessis, George P. Simon, Yi Bing Cheng

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33 Citations (Scopus)


Binder-free titania pastes with high viscosity were developed for the preparation of electrodes for dye-sensitized solar cells on plastic substrates. The rheological behaviour of the ethanol-based titania pastes with the addition of ammonia, hydrochloric acid and water was investigated. The change in the viscosity could be correlated with the measured zeta-potential of the colloidal titania pastes. A newly developed nano-scratch test was used to evaluate the mechanical strength or the inter-particle connectivity of the titania films prepared under different conditions. Improved inter-particle connectivity and solar cell performance were found for the pastes containing acid or water, but no such improvements were seen for the pastes containing ammonia. A maximum light-to-electrical energy conversion efficiency of 4.9% (under one sun - 100 mW cm-2) was obtained for the plastic-based dye-sensitized solar cells fabricated by the modified titania pastes.

Original languageEnglish
Pages (from-to)9954-9961
Number of pages8
JournalJournal of Materials Chemistry
Issue number44
Publication statusPublished - 28 Nov 2010

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