Dresden 2011 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 55: Photovoltaics: mainly Technology and Photon Management

HL 55.3: Talk

Wednesday, March 16, 2011, 15:00–15:15, FOE Anorg

Light scattering by rough surfaces for increase of absorption of low band gap light in solar cells — •Konstantin Kloppstech, Sebastian Knabe, and Gottfried H. Bauer — Institute of Physics, Carl von Ossietzky University Oldenburg, Germany

Scattering of low band gap light for the increase of the absorption of low band gap photons is commonly formulated in phenomenological magnitudes such as haze factors resulting from experiments at particular scattering media. We have formulated analytically and described by numerical simulations the scattering of light by the interaction of photons with rough surfaces based on wave numbers of photons k_λ and wave numbers of the topological surface contour k_s that has been derived in 2 dimensions via AFM analyses of the contour function h(x,y) of the scattering medium, e.g. a glassy diffusor. We have distinguished two regimes: i) k_λ<k_s in which we apply a ray tracing approach with respect to Snellius’ Law for photon propagation at phase border between different media, and ii) k_λ ∝ k_s, where the propagation of photons after scattering has been formulated on Huygens’ Principle with generation of spherical waves at the respective position h(x,y). The experimental scattering of photons with different wavelengths - recorded with a standard type goniometer - are compared with the simulation of numerically generated far field results in dependence of distance r from the scattering medium and scattering angle β. In particular for the wave optical approach we find a "scattering function" that contains the contour function h(x,y) however that substiantially departs from its puristic Fourier Transform.