Elementary processes and limiting factors in hybrid polymer/nanoparticle solar cells

Semiconductor nanoparticles are promising for use as electron acceptors in polymer-based bulk heterojunction solar cells. Potential advantages over fullerene derivates that are widely used in organic photovoltaics are tuneable absorption properties and the possibility to use elongated nanoparticles for more efficient electron transport. Despite these advantages, efficiencies obtained with hybrid polymer/nanoparticle solar cells are still below those of state-of-the-art polymer/fullerene solar cells. This Perspective summarises the achievements in the field of hybrid solar cells, compares the knowledge on elementary processes in hybrid and organic systems and points out the most recent trends in research. The design of the polymer nanoparticle/interface by the choice of capping ligands and development of appropriate surface treatments for the nanoparticles plays an important role, and recent progress opens new perspectives for the future improvement of hybrid solar cells.