Comparative Study Between Various Antireflective Coatings For Solar Cells Applications

Abstract

The incessant progress in thin layers technology, especially inhomogeneous materials with variable index allows the fabrication of antireflective coating (ARC) less sensitive to the thickness and the incidence angle. Accordingly, our work is devoted to study the optical behaviour of graded refractive index ARC made from: silicon oxynitrides (SiOxNy), mixture of silicon and titanium oxides (SiO2-TiO2) and porous silicon (P-Si), for solar applications. The refractive index of the studied ARC varies versus thickness according to Fermi profile variation law. The physical parameters of such coating are its: thickness, form factor, profile inflection point and silica or air (porosity) volume fraction variation at the two interfaces (air/ARC and ARC/substrate). The optimisation of the studied films performance shows that best results are obtained with P-Si ARC, which reduce weighted reflectance till to 1.86% (between 300-1100 nm) leading to an improvement in photogenerated current of 51%.