Nanoengineered devices for solar energy conversion

Nanoengineered materials have exciting, untapped potential to develop high performance solar energy conversion systems. One example is in solar thermophotovoltaic devices, where solar energy can be harvested by converting broadband sunlight to narrowband thermal radiation tuned for a photovoltaic cell. We show how nanoengineered surfaces including a carbon nanotube absorber, photonic crystal emitter and a tandem plasma-interference optical filter can play important roles in defining the spectral characteristics. Accordingly, we report solar-to-electrical conversion efficiencies of 6.8%, exceeding that of the underlying cell. Such nanoengineered materials also have important implications for various other solar thermal devices to address important needs in energy sustainability.