Absorption Enhancement in Solar Cells With Periodic Interface Textures of Asymmetric Shape

We investigate light scattering interface textures for solar cells with the intention to obtain a more fundamental understanding of the absorption enhancement. Therefore, we study simplified structures with the periodic interface texture of sinusoidal and blazed shape, and we employ a theoretical model with moderate complexity on the basis of the Rayleigh method. We test our model by comparing diffraction effects with theoretical predictions for the two possible polarization directions. The intensity of first-order diffraction is virtually insensitive to the asymmetry of the grating for both s- and p-polarizations. However, in the latter case, the absorption signature of the surface plasmon resonances does show a mild asymmetry. Subsequently, we extend the model to multilayers such as a full solar cell stack, which allows us to relate the measured absorption enhancement to the interface texture.