Large area vertical alignment of ZnO nanowires in semiconducting polymer thin films directed by magnetic fields.

We demonstrate the use of magnetic fields for the directed assembly of ZnO nanowires in semiconducting polymer films suitable for ordered bulk heterojunction photovoltaics. Using rotational field annealing, Co-doped ZnO nanowires with negative paramagnetic anisotropy were successfully aligned out-of-plane with respect to the substrate and polymer film.