Fig. 4
From: Biomimetic light-harvesting funnels for re-directioning of diffuse light
Potential photoprotective concentrator architectures. The leaflet-like structure and perpendicular emission of the funneling and re-directing foils is ideal for harvesting architectures using materials of best transparency and waveguiding properties. a A possible architecture that allows for large absorption angle ranges, optimized emission angle ranges, and very little re-absorption and reflection losses. The light harvesting to photovoltaics area ratio is about 25:1. b Alternative architecture with additional lenses for collecting highly intensive direct sunlight irradiation. This architecture intrinsically switches between efficient light harvesting by photon-redirection of diffuse light under cloudy or shady conditions and direct lens focusing with concomitant pigment protection under intense direct sun irradiation. c The hexagonal shape of the proposed architecture allows for larger area arrangements keeping the optical pathways between pigments and photovoltaics small. Electrical access to photovoltaic elements is possible from the bottom. d The architecture also allows for stack structures redirecting light to high-efficient photovoltaics for each spectral range
