Enhancement of solar thermoelectric power generation by optical and thermal management with highly transparent aerogel window

Solar thermoelectric generators (STEGs), which convert solar thermal energy into electricity, are studied as an environmentally friendly energy source. The unique properties of aerogels (i.e., high thermal insulation and solar light transmission) are essential factors in the solar-receiving components of STEGs. Herein, STEG power generation is enhanced through optical and thermal management using a highly transparent aerogel window. The aerogel window (thickness: 5 mm) exhibits an extremely low thermal conductivity and a high solar transmittance of 96.5%, higher than that of soda-lime glass (89.9% at 0.5 mm thickness) in the wavelength range of 300–2500 nm. Furthermore, we use a copper oxide (CuO) nanoflake structure as a cost-effective solar absorber for the STEG. Under 1-sun (1 k W m⁻²) illumination, power generation of the STEG with the aerogel window is 21% and 17% higher than that of glass-covered and uncovered STEGs, respectively. To demonstrate the performance of aerogel in an open environment, we measure the power generation of aerogel-covered, glass-covered, and uncovered STEGs under wind conditions. Under 1-sun illumination and a wind speed of 3 m s⁻¹, the power generation of the STEG with the aerogel window is 54% and 71% higher than that of glass-covered and uncovered STEGs, respectively.