Built-in potential shift and Schottky-barrier narrowing in organic solar cells with UV-sensitive electron transport layers.

The performance of organic solar cells incorporating solution-processed titanium suboxide (TiOx) as electron-collecting layers can be improved by UV illumination. We study the mechanism of this improvement using electrical measurements and electroabsorption spectroscopy. We propose a model in which UV illumination modifies the effective work function of the oxide layer through a significant increase in its free electron density.

Bio-inspired hierarchical polymer fiber-carbon nanotube adhesives.

Hierarchical pillar arrays consisting of micrometer-sized polymer setae covered by carbon nanotubes are engineered to deliver the role of spatulae, mimicking the fibrillar adhesive surfaces of geckos. These biomimetic structures conform well and achieve better attachment to rough surfaces, providing a new platform for a variety of applications.

Solvent additive control of morphology and crystallization in semiconducting polymer blends.

4-bromoanisole is used as a very versatile processing additive to control the phase separation and phase purity of organic photovoltaic devices. Polymer-polymer blends based on P3HT as donor and a wide range of acceptor materials (F8TBT, PCDTBT,…︁) are investigated. The additive promotes the aggregation of P3HT which improves the morphology for both initially mixed and demixed blends.