Guided-mode absorption in ultrathin organic photovoltaics

We introduce a novel organic photovoltaic (OPV) design, termed a “slot OPV”, that applies the principles of slot waveguides to confine light within the ultrathin (<; 50 nm) active layer of an OPV. Our calculations demonstrate that a “slot OPV” can be designed with guided-mode absorption for a 10 nm thick active layer equal to the absorption of normal incidence on an OPV with a 100 nm thick active layer. These results, together with the expected improvement in charge extraction for ultrathin layers, suggest that “slot OPVs” can be designed with greater power conversion efficiency than today's state-of-the-art OPV architectures.