Ultrathin nanostructured solar selective absorber based on a two-dimensional hemispherical shell array

• A distinctive ultrathin nanostructured solar selective absorber is demonstrated experimentally. It consists of a self-assembled, two-dimensional, closely packed hexagonally distributed tungsten hemispherical shell array coated with an ultrathin germanium film (20 nm in thickness) and a silicon dioxide antireflective film. Due to the combined light trapping effects of unconventional interferences within the germanium film and the excited surface plasmon polaritons at the tungsten-germanium interface, as well as the antireflection effect of the silicon dioxide layer, the solar absorption of this absorber (0.93) is about as high as that of commercial black paint (0.94) and much higher than that of its planar counterpart (0.83). With greatly suppressed emission/absorption in the long wavelength range, its heat accumulation is superior, enabling a much higher temperature (218 °C under 7-sun illumination) than its planar counterpart and the black paint absorber (203 °C and 181 °C under 7-sun illumination, respectively). 

Ämnesord

NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

Nyckelord

Electromagnetic wave polarization

Germanium

Interfaces (materials)

Paint

Silica

Tungsten

Anti-reflection effects

Antireflective films

Heat accumulation

Hemispherical shells

Light trapping effects

Long-wavelength-range

Silicon dioxide layers

Surface plasmon polaritons

Solar absorbers

Publikations- och innehållstyp

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