Fourier analysis for the study of light scattering properties of randomly textured ZnO films

We introduce a model which allows for the description of scattering properties of randomly textured ZnO films by evaluating a Fourier surface analysis. The interface is developed into a series of periodic gratings with well defined diffraction angles. The scattering efficiency is assumed to be the Fourier transform of the surface profile. This model is applied on different kinds of textures and compared with experimentally obtained angularly resolved scattering. This Fourier model is extended to obtain the scattering properties with both spatial and angular resolution which allows the study of the light scattering of individual surface elements. The identification of structures which scatter light into larger angles is possible. The calculated scattering properties show a good agreement to the experimentally obtained data. The results are essential for the further improvement of surface texture to optimize light trapping in thin-film solar cells.