Fully interactive: Overlap between extended unoccupied molecular orbitals leads to the high photoconductivity of interactive radical dimers. Sandwich-type cells (see picture; ITO = indium tin oxide) comprising highly oriented thin films of a disjoint diradical, 4,4'-bis(1,2,3,5-dithiadiazolyl) (BDTDA) exhibit a photocurrent with a high on/off ratio at reverse bias voltages and photovoltaic behavior at zero bias voltage.