Embedded silver nanoparticle fabrication for surface plasmon-enhanced silicon photovoltaics

To reduce cost and maintain viability of silicon-based solar cells for commercial applications, the absorption of thin silicon films, on the order of a few microns, must be enhanced. We are developing a method to increase absorption across the solar spectrum by exploiting the enhanced electric near field caused by surface modes of excited metallic particles. Previous research in the field has focused on deposition of these particles on a passivated Si surface, a technique that scatters light in directions lateral to the cell, but does not promote direct carrier generation, as the near field enhancement is too far from the Si itself. Consequently, we have developed a method using ion implantation and thermal evaporation to fabricate Ag nanoparticles below the Si surface, near the p-n junction, where the enhanced near field can greatly enhance the absorptive response of the silicon solar cell.