Spectral Response of a Monocrystalline Silicon Solar Cell: Under the Influence of the Variation of the Refractive Indices of the Antireflection Materials

Numerical simulations have shown that low reflectivity’s at the surface of the planar cell coated with a single layer can be obtained. For example, for single coatings of Si3N4 and HfO2 materials, reflectivity values of around 3% and 2% respectively are obtained. Structures with multilayer coatings such as MgF2 /SiNx: H/Si, give a very low reflectivity of around 1%. Thus, the refractive index of the coating is an important parameter that plays a major role in the optical properties of the materials. The closer the refractive index is to the index of the substrate or the layer above the substrate, the higher the reflectivity. The low reflectivity’s of silicon coated with anti-reflective materials increase the external quantum efficiency of the solar cell; for example, the efficiency is 95% for HfO2 /Si and Si3N4 /Si, as there is a maximum incident photon flux within the solar cell.