Becker, C.; Preidel, V.; Sontheimer, T.; Klimm, C.; Rudigier-Voigt, E.; Bockmeyer, M.; Rech, B.: Direct growth of periodic silicon nanostructures on imprinted glass for photovoltaic and photonic applications. Physica Status Solidi C 9 (2012), p. 2079-2082
Large-area (50 cm2) two-dimensionally periodic crystalline silicon structures with lattice constants between 350 nm and 2 μm were prepared by high-rate electron-beam evaporation of silicon on nanoimprinted glass substrates. All processing steps have little technological intricacy, are up-scalable to large areas, and thus hold the potential for low-cost production of advanced nanostructured photovoltaic devices or large-area 2D photonic crystals. The 2 μm-periodic materials exhibit a promising absorption enhancement with light path enhancement factors larger 40 at λ=1000 nm enabling the development of highly effective light trapping architectures for polycrystalline silicon thin-film solar cells. Photonic band structure effects at near infrared wavelengths could be identified by angular resolved reflection measurements in hexagonal 350nm-periodically patterned silicon films inspiring the formation of large-area two-dimensional photonic crystals for telecommunication wavelengths.