Enhanced carrier collection and light harvesting of polymer solar cells using embedded indium-tin-oxide nano-electrods

Distinctive indium-tin-oxide (ITO) nanorods are employed to serve as buried electrodes for polymer-based solar cells. The embedded nano-electrodes allow three-dimensional conducting pathways for low-mobility holes, offering a highly scaffolded cell architecture in addition to bulk heterojunctions. As a result, the power conversion efficiency and photocurrent of a polymer cell with ITO nano-electrodes demonstrates an enhancement factor of up to ~13.1% and 10% respectively, compared to a conventional cell. Furthermore, ITO nanostructures improved optical absorption not only for a wide range of wavelengths, but also at large angles of incidence (AOIs). Hence, devices with 3-D nanoelectrodes exhibited nearly ideal angular response of J_sc, implying great potentials for polymer or other thin-film solar cells.