Absorption Enhancements in Plasmonic Solar Cells Coated with Metallic Nanoparticles

We find that three mechanisms lead to the absorption enhancements of light in a thin-film amorphous silicon solar cell coated with a periodic array of silver nanoparticles on the rear surface according to our simulation. They are localized surface plasmon modes of the silver nanoparticles, Fabry–Pérot resonant cavity modes and waveguide effects. Each enhancing mechanism can yield a maximum absorption enhancement of over two times at the corresponding resonant wavelengths when the nanoparticles cover 20 % of the solar cell surface, and an average absorption enhancement of up to 57 % can be achieved in the AM 1.5 G solar spectrum. The absorption enhancements can also be tuned in spectrum to optimize the total absorption in a plasmonic solar cell.