High-temperature solar absorbers for solar thermal systems

High-temperature solar absorbers for solar thermal systems are complementary to solar cells as another way of harvesting solar energy. The energy conversion efficiency increases with the working temperature of solar thermal systems according to the second law of thermodynamics. A critical component to achieve high working temperature is solar absorber coatings, which should absorb sunlight and convert it to heat efficiently with minimal thermal radiation loss in the infrared regime. They should also be stable at high temperatures. In this research we are investigating optical absorbers based on oxidation-resistant cermet materials incorporating metallic nanoparticles in a ceramic matrix for a working temperature of >560 C. Instead of using metal nanoparticles which are either easily oxidized at this temperature or too expensive to apply in large quantities, we are exploring certain metallic compounds that combines metal-like optical absorption properties with ceramic-like chemical stability. We also engineer the microstructure of the coating to trap infrared thermal radiation within the solar absorber coating and further increase the working temperature.

Faculty contact: Jifeng Liu