Design and optimization of Ag-dielectric core-shell nanostructures for silicon solar cells.

Metal-dielectric core-shell nanostructures have been proposed as a light trapping scheme for enhancing the optical absorption of silicon solar cells. As a potential application of such enhanced effects, the scattering efficiencies of three core-shell structures (Ag@SiO₂, Ag@TiO₂, and Ag@ZrO₂) are discussed using the Mie Scattering theory. For compatibility with experiment results, the core diameter and shell thickness are limited to 100 and 30 nm, respectively, and a weighted scattering efficiency is introduced to evaluate the scattering abilities of different nanoparticles under the solar spectrum AM 1.5. The simulated results indicate that the shell material and thickness are two key parameters affecting the weighted scattering efficiency. The SiO₂ is found to be an unsuitable shell medium because of its low refractive index. However, using the high refractive index medium TiO₂ in Ag@TiO₂ nanoparticles, only the thicker shell (30 nm) is more beneficial for light scattering. The ZrO₂ is an intermediate refractive index material, so Ag@ZrO₂ nanoparticles are the most effective core-shell nanostructures in these silicon solar cells applications. [ABSTRACT FROM AUTHOR]