Theoretical Analysis of Metamaterial – Multilayer Waveguide Structures for Solar Cells

Abstract

Abstract Solar cells are photoelectric devices convert sun light to electric power through semiconductors. The main problem of solar cells is the limit of the transmission and absorption of the sun light which causes the low efficiency. When used as Anti-Reflection Coatings (ARCs), Metamaterials under certain conditions could be a useful choice to increase the transmision and the absorption of the incident radiation. The main purpose of this study is to suggest a new waveguide structure containing a metamaterial ARC capable of reducing the reflection and enhancing both the transmission and the absorption of the sun light incident on the solar cell in order to increase its efficiency. The proposed structure of the ARC consists of 4-layers (air, metamaterial, silicon nitride ( ) and Gallium Arsenide (GaAs) as a substrate). Analytical and mathematical methods such as the boundary conditions, transfer matrix and Fresnel's equations are used to calculate the reflection, transmission and absorption and determined the optimal values of the parameters for each layer as the electric permittivity ( ), magnetic permeability ( ) and thickness, in addition to the angle of incidence. A computer software (Maple 13) is used to analyse and carry out the results. The study shows that the maximum transmittance and absorbance are achieved under certain conditions when the Gallium Arsenide (GaAs) solar cells are covered by the proposed ARCs.