Photovoltaics are the fastest-growing renewable energy source over the last three years and have the potential to supply a significant fraction of our electricity needs. Conventional silicon cells are made of thick crystals because silicon is a weak absorber in the infrared and much of the visible. Thin solar cells require less energy and material to make and may lead more swiftly to widespread deployment of photovoltaics.
A challenge facing thin cells is to maximize the absorption of the solar spectrum. We explore the enhancements to absorption in thin-film cells made possible by metallic nanoparticles and other structures designed to scatter incident radiation into guided modes propagating parallel to the cell’s surface.