Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

Antireflective transparent covers for solar devices

: Gombert, A.; Glaubitt, W.; Rose, K.; Dreibholz, J.; Bläsi, B.; Heinzel, A.; Sporn, D.; Döll, W.; Wittwer, V.

Solar energy 68 (2000), Nr.4, S.357-360
ISSN: 0038-092X
ISSN: 0375-9865
Fraunhofer ISE ()
Fraunhofer IWM ()
Fraunhofer ISC ()

Promising solutions for low-cost antireflective (AR) covers for solar receivers are based on the principle of mixing bulk material with air on a subwavelength scale in order to obtain very low effective refractive indices. Possibilities to achieve this are given by porous media and by periodic or stochastic subwavelength surface-relief structures. In this work, the mentioned approaches were investigated experimentally. Subwavelength surface-relief structures were embossed in organically modified sol - gel materials or in acrylic materials, and porous sol - gel coatings were produced by dip-coating. It is shown that the solar transmittance of a transparent cover can be improved by up to 6% with a porous sol - gel coating at normal incidence. This improvement of the solar transmittance increases with larger angles of incidence.