A multi-institutional team has developed an optical coating capable of simultaneously reflecting and transmitting the same wavelength. The new class of optical coatings has been dubbed Fano Resonance Optical Coatings (FROCs).
Previously, optical coatings were limited to reflecting certain wavelengths of light, or, conversely, to better transmit certain wavelengths through them. With the new technology, thermal and photovoltaic bands of the solar spectrum can be separated. The advance could significantly improve the efficiency of devices using hybrid thermal-electric power generation as a solar energy option. Separating those bands can prevent photovoltaic cells from overheating.
The Fano Resonance Optical Coating technology may have the potential to enable a sixfold increase in the life of a photovoltaic cell, the researchers reported. In application, the remaining spectra are absorbed as thermal energy that could be used in other ways, including energy storage, electricity generation, solar-driven water sanitation, or heating up a supply of water.