UV-cured TiO2 electron transport layers for printable solar cells

Abstract

This article is focused on the development of new formulations of inks for printed electron transport layers based on titanium oxide. The electron transport layers were prepared from a suspension consisting of titania nanoparticles and a novel organo-silica binder. The layers are post-processed by low temperature UV curing instead of thermal annealing. The UV-cured TiO₂ layers were applied in inverted-structure organic bulk heterojunction solar cells with the active layer from a PCDTBT : PC₆₀BM blend. These devices achieved a power conversion efficiency comparable to devices with TiO₂ layers prepared by the common sol–gel process relying on high-temperature calcination. Thus the novel UV curable TiO₂ formulation is promising as printable electron transport layers for flexible devices, which are not compatible with thermal processing.