Dielectric-Metal Nanostructures for Enhanced Scattering and Absorption in Solar Cells

The primary feature of the metallic nanostructures is their localized surface response at optical frequency resulting in enhanced scattering and absorption. Among these nanostructures, nanoparticles and nanoshells are known for their three-dimensional symmetry, with stand-alone responses naive to the state of incident wave polarization. Nanoparticles can confine and trap light and are often used as a basic building block in metamaterials and metasurfaces employed for silicon solar cells, which require light enhancement due to their narrow bandgap and limited absorption. However, they have shown a limited ability for enhanced scattering and absorption of light. Nanoshells also known as coated spheres have shown superior optical response compared to nanoparticles. In this paper, we propose the nanoshell as a basic building block for metasurfaces and demonstrate their superior scattering and absorption response for improved energy harvesting in solar cells. The proposed model derives expressions to maximize energy absorption and forward scattering using basic concepts from applied mathematics and linear circuit theory. The superior response of the proposed solution is demonstrated using a numerical field solver and Mie theory to evaluate specific examples with various radius and interparticle distances. The developed solution is highly efficient, with improved scattering and absorption, which is well-suited for next-generation solar cells.