Photovoltaic structures are disclosed. The structures can comprise randomly or periodically structured layers, a dielectric layer to reduce back diffusion of charge carriers, and a metallic layer to reflect photons back towards the absorbing semiconductor layers. This design can increase efficiency of photovoltaic structures. The structures can be fabricated by nanoimprint.
STATEMENT OF INTEREST
 This invention was made with government support under Grant No. DE-EE0004946/T-107934 awarded by the Department of Energy. The government has certain rights in the invention.