title: Dielectric Scattering Patterns for Efficient Light Trapping in Thin-Film Solar Cells.
abstract: We demonstrate an effective light trapping geometry for thin-film solar cells that is composed of dielectric light scattering nanocavities at the interface between the metal back contact and the semiconductor absorber layer. The geometry is based on resonant Mie scattering. It avoids the Ohmic losses found in metallic (plasmonic) nanopatterns, and the dielectric scatterers are well compatible with nearly all types of thin-film solar cells, including cells produced using high temperature processes. The external quantum efficiency of thin-film a-Si:H solar cells grown on top of a nanopatterned Al-doped ZnO, made using soft imprint lithography, is strongly enhanced in the 550-800 nm spectral band by the dielectric nanoscatterers. Numerical simulations are in good agreement with experimental data and show that resonant light scattering from both the AZO nanostructures and the embedded Si nanostructures are important. The results are generic and can be applied on nearly all thin-film solar cells.
authors.affiliation: †Center for Nanophotonics, FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands.
authors.forename: Claire
authors.initials: C
authors.lastname: van Lare
authors.affiliation: ‡Energy Research Center of The Netherlands, P.O. Box 1, 1755 ZG Petten, The Netherlands.
authors.forename: Frank
authors.initials: F
authors.lastname: Lenzmann
authors.affiliation: §Philips Research Laboratories, High Tech Campus 34, 5656 AE Eindhoven, The Netherlands.
authors.forename: Marc A
authors.initials: MA
authors.lastname: Verschuuren
authors.affiliation: †Center for Nanophotonics, FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands.
authors.forename: Albert
authors.initials: A
authors.lastname: Polman
mesh_terms: D000535:Aluminum / Q000737:chemistry*; D011211:Electric Power Supplies; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology; D012542:Scattering, Radiation; D012825:Silicon / Q000737:chemistry; D012993:Solar Energy; D013472:Sunlight; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D000535:Aluminum; D015034:Zinc Oxide; D012825:Silicon
keywords: Thin film solar cells; geometrical resonances; light trapping; nanophotonics; resonant nanostructures