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
JOURNAL OF MATERIALS CHEMISTRY | ROYAL SOC CHEMISTRY | Published : 2010
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 s..View full abstract
Financial support by the Victorian Consortium in Organic Solar Cells (VICOSC) is greatly appreciated by the authors. RMIT Microscopy & Microanalysis Facility (RMMF) for SEM and XPS analysis are also appreciated by the authors. The authors are also thankful to Stephen Tandurjaja for the help with rheology measurements, A/Prof. Ray Dagastine and Stephan Suherman for the help with Lifshitz calculations, Dr Alan Greig and Prof. Janet Hergt of the School of Earth Sciences, University of Melbourne for conducting the ICP-MS measurements.