Front Side Structures in TiO2 for Crystalline Silicon Solar Cells. Which Effects can they Achieve?

Light trapping and reflection reduction are essential, in order to enhance the absorption of silicon solar cells. State of the art in industry is texturization using wet chemical etching of the front surface in combination with the deposition of antireflection coatings to improve the solar cell optics. Within this work an alternative route, namely a TiO2 coating with nano structures on the front side of a planar silicon solar cell encapsulated in ethylene vinyl acetate (EVA) and glass, is analyzed. The focus is put on the experimental realization of such a system. Optical measurements are compared to optical simulations using the rigorous coupled wave analysis (RCWA) and the OPTOS method. Good agreement between measurements and simulation was found, so the simulation modell can be used in the future for prediction of the optical perfomance of different structures even in a PV-module.