Light scattering and parasitic absorption in thin film silicon solar cells containing metal nanoparticles

The efficiency of thin film silicon modules needs to further improve in the long term to stay competitive with other photovoltaic technologies.Advanced super light trapping designs can be implemented in thin film silicon devices for this purpose.Different approaches are possible and in this work we report on plasmonic back reflectors and intermediate layers designed to enhance optical reflection over conventional device structures.Metal nanoparticles are embedded in thin film single and tandem junctions with the purpose to increase light scattering back into the active layers of the solar cell.Results show that metal nanoparticles do not compromise the electrical solar cell parameters; however, the current increase proves to be elusive in most cases.The data suggest that a better control of the metal nanoparticle size and distribution might be needed in order to harness the full benefits of plasmonic effects in thin film silicon devices.