DESIGN AND OPTIMISATION OF THIN-FILM SILICON PV MODULES WITH SURFACE-TEXTURED FRONT GLASS BY USING A COMBINED GEOMETRIC OPTICS / WAVE OPTICS MODEL

摘要

Light management techniques are crucial for improving the conversion efficiency of thin-film siliconsolar cells and PV modules. In this respect, light scattering at textured interfaces is important for increasing thephotocurrent by prolonging the effective optical paths of the light passing through the device. In this paper, numericalsimulations are employed to study the light-trapping potential of large micro-scale surface textures applied on top ofthe front protective glass sheets in thin-film a-Si:H PV modules. The simulations are based on the newly developedoptical model which combines incoherent geometric optics analysis and fully-coherent wave optics analysis. Usingthe simulations, we investigate the potential of different surface-texture morphologies of the front glass (triangular,U-like, inverted U-like) with different dimensions of texture features (period and peak-to-peak height) in order todetermine the optimal textures that result in maximal short-circuit current densities. Simulation results indicate thatoptimized front micro-scale surface textures of thin-film a-Si:H PV modules significantly improve light trappingwithin the underlying solar cell. Optimized U-like textures are especially advantageous, as they are able to assureconsistently low reflectance from the PV module in both perpendicular as well as oblique illumination conditions.