title: Light trapping in solar cells: numerical modeling with measured surface textures.
abstract: We present and experimentally validate a computational model for the light propagation in thin-film solar cells that integrates non-paraxial scalar diffraction theory with non-sequential ray-tracing. The model allows computing the spectral layer absorbances of solar cells with micro- and nano-textured interfaces directly from measured surface topographies. We can thus quantify decisive quantities such as the parasitic absorption without relying on heuristic scattering intensity distributions. In particular, we find that the commonly used approximation of Lambertian scattering intensity distributions for internal light propagation is violated even for solar cells on rough textured substrates. More importantly, we demonstrate how both scattering and parasitic absorption must be controlled to maximize photocurrent.
authors.forename: Thomas
authors.initials: T
authors.lastname: Lanz
authors.forename: Kevin
authors.initials: K
authors.lastname: Lapagna
authors.forename: Stéphane
authors.initials: S
authors.lastname: Altazin
authors.forename: Mathieu
authors.initials: M
authors.lastname: Boccard
authors.forename: Franz-Josef
authors.initials: FJ
authors.lastname: Haug
authors.forename: Christophe
authors.initials: C
authors.lastname: Ballif
authors.forename: Beat
authors.initials: B
authors.lastname: Ruhstaller