Over the past few years, several research groups have emphasized the outstanding light harvesting and self cleaning properties of photovoltaic (PV) cover layers replicating the original surface texture of leaves and petals. Especially, the hierarchical micro-/nanotexture found on rose petals emerged as promising candidate to both increase the PV energy yield and simultaneously reduce maintenance costs by introducing water repellency. In the present contribution, we report on our recent efforts aimed at developing large-area rose petal replicas that can be applied onto real-world PV modules, and on the performance and the ecological impact of these textured layers under field conditions.
We first present a biotemplating approach, which culminates in a reproducible multi-step fabrication sequence of 125 cm2 polymeric rose petal replicas based on a hot embossing process . On that basis, the lamination of such replicas made in PMMA onto copper indium gallium diselenide (CIGS) solar modules and the optoelectronic properties of the resulting devices are discussed. We demonstrate that, under field conditions and over the course of 50 days, the energy yield of CIGS modules equipped with rose petal replicas increases by 5.4 % relative to equivalent PV modules protected by a planar glass cover layer. In addition, we experimentally and numerically prove that these textured replicas allow manipulating the polarization state of light being reflected from their surfaces in a way such that they do not cause “polarized light pollution”, a hazard for many polarotactic insect species . Our findings show that plant surface texture replicas have the potential to improve the devices performance while minimizing the deleterious impact of massively deployed PV modules on the entomofauna.
 B. Fritz, M. Guttmann, P. Casas Soler, A. Roslizar, M. Langenhorst, M. Schneider, U. W Paetzold, B. S Richards, U. Lemmer, R. Huenig, and G. Gomard. “Towards mass fabrication of hot embossed plant surface texture replicas as photovoltaic cover layers.” In: Nanoengineering: Fabrication, Properties, Optics, and Devices XV. Vol. 10730. International Society for Optics and Photonics. 2018, 107300J. doi: 10.1117/12.2320555
 G. Horváth, G. Kriska, P. Malik, and B. Robertson. “Polarized light pollution: a new kind of ecological photopollution.” In: Frontiers in Ecology and the Environment 7 (6 2009), pp. 317–325. doi: 10.1890/080129