The morphology of TiO2 plays an important role in the operation of solid-state dy-sensitized solar cells. By using polyisoprene-block-ethyleneoxide (PI-b-PEO) copolymers as structure directing agents for a sol-gel based synthesis of mesoporous TiO2, we demonstrate a strategy for the detailed control of the semiconductor morphology on the 10nm length scale. The careful adjustment of polymer molecular weight and titania precursor content is used to systematically vary the material structure and its influence upon sollar cell performance is investigated. Furthermore, the use of a partially sp2 hybridized structure directing polymer enables the crystallization of porous TiO2 networks at high temeratures without pore collapse, improving its performance in solid-state dye-sensitized solar cells. The Publisher Version is available at: http://pubs.rsc.org/en/Content/ArticlePDF/2009/SM/B815166K/2008-11-07