Improved conductivity in dye-sensitised solar cells through block-copolymer confined TiO2 crystallisation
By Guldin, Stefan; Huttner, Sven; Tiwana, Priti; Orilall, M. Christopher; Ulgut, Burak; Stefik, Morgan; Docampo, Pablo; Kolle, Matthias; Divitini, Giorgio; Ducati, Caterina; Redfern, Simon A. T.; Snaith, Henry J.; Wiesner, Ulrich; Eder, Dominik & Steiner, Ullrich
Published in Energy Environ. Sci.
The Royal Society of Chemistry
2011
Abstract
Anatase TiO2 is typically a central component in high performance dye-sensitised solar cells (DSCs). This study demonstrates the benefits of high temperature synthesised mesoporous titania for the performance of solid-state DSCs. In contrast to earlier methods, the high temperature stability of mesoporous titania is enabled by the self-assembly of the amphiphilic block copolymer polyisoprene-block-polyethylene oxide (PI-b -PEO) which compartmentalises TiO2 crystallisation, preventing the collapse of porosity at temperatures up to 700 [degree]C. The systematic study of the temperature dependence on DSC performance reveals a parameter trade-off: high temperature annealed anatase consisted of larger crystallites and had a higher conductivity, but this came at the expense of a reduced specific surface area. While the reduction in specific surface areas was found to be detrimental for liquid-electrolyte DSC performance, solid-state DSCs benefitted from the increased anatase conductivity and exhibited a performance increase by a factor of three.