Organic photovoltaics (OPVs) are considered to have a great potential to solve future energy supply scenarios due to their advantages such as low production and material costs. The power conversion efficacy and lifetime of bulk heterojunction OPVs have been significantly increasing in the last decade, although further improvements will be required for the large-scale commercialization. Because the OPV cell includes a stack of several thin layers, a certain percentages of light energy is always lost by the reflection at the interfaces between the different materials and the absorption in the layers different from the photoactive layer. In addition, due to a low carrier mobility of organic semiconductors, the active layer of OPVs should be very thin (around 100 nm), which makes it difficult to fully absorb incident light. To enhance light absorption in the thin active layer, it is important to adequately design antireflection (AR) system that can trap light into OPVs. Recently, many studies on the AR technique have applied the moth eye texture, which is a nanostructure inspired by the corneal surface of moth’s eyes. In the moth eye coating, the device surface is covered with two-dimensional array of cones with a period and height of a few hundred nanometers. Since the effective refractive index (RI) within the moth eye gradually changes in the direction of the cone axis, the level of reflection can be significantly weakened. In cases where the moth eye texturing is applied to OPVs, it is required that the material used in the texture should have compatibility with the advantage of the OPVs, such as low costs. Therefore, in this study, we employ moth eye structure made by organic polymers, since the textured pattern can be fabricated cost-effectively by nanoimprint lithography with polymeric resists. To reduce the effects of optical mismatch between the low-RI organic polymers and high-RI materials in the OPV cell (e.g., indium-doped tin oxide), we propose a new design of AR system. In this system, the hybrid AR structure, which is composed of the moth eye and multilayer interference coatings, is integrated with a high-RI glass substrate. We numerically investigate the optical properties of OPVs and demonstrate that the proposed AR system is quite useful for attaining broadband and omnidirectional antireflection. In addition, we experimentally measure the effect of the integrated AR design on the photocurrent generation of OPVs to verify the simulation results.Acknowledgement: This study was partially supported by KAKENHI (26390025) from the Japanese government, and by JST, CREST.