Abstract
The fabrication of solar cells made from organic molecular solids rather than inorganic materials has the potential to be easy and cost-efficient. But prototype devices tend to have low quantum efficiencies because charge carriers get trapped and recombine before they can reach their opposite electrodes. In her Perspective, Nelson charts recent progress toward more efficient organic solar cells. She highlights the report by Schmidt-Mende et al., in which mesoscopic ordering of two blended phases is exploited to increase quantum efficiency.