Block copolymer directed synthesis of mesoporous TiO2 for dye-sensitized solar cells

Abstract

The morphology of TiO₂ plays an important role in the operation of solid-state dye-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 10 nm 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 solar cell performance is investigated. Furthermore, the use of a partially sp² hybridized structure directing polymer enables the crystallization of porous TiO₂ networks at high temperatures without pore collapse, improving its performance in solid-state dye-sensitized solar cells.