Abstract
Spectrally selective absorbers have received considerable interest due to their applications in thermophotovoltaic devices and as solar absorbers. Due to extreme operating conditions in these applications, such as high temperatures, thermo-mechanically stable and broadband spectrally selective absorbers are of interest. This paper demonstrates anisotropic random rough surfaces that provide broadband spectrally selective absorption for the thermo-mechanically stable Tungsten surfaces. Anisotropic random rough surface has different correlation lengths in the x- and y-directions, which means their topography parameters have directional dependence. In particular, we demonstrate that spectral absorptance of Tungsten random rough surfaces at visible (VIS) and near-infrared (NIR) spectral regions are sensitive to correlation length and RMS height variations. Our results indicate that by optimizing random rough surface parameters, absorption values exceeding 95% can be obtained. Moreover, our results indicate that anisotropic random rough surfaces broaden the bandwidth of the high absorption region. It is shown that in VIS and NIR regions, the absorption enhancements of up to 47% and 52% are achieved for the isotropic and anisotropic rough surfaces, respectively.
Highlights
Thermal solar [1,2,3], solar thermophotovoltaic [4], nuclear fusion [5,6,7], and aerospace applications [8] rely heavily on materials capable of operating at high temperatures
In the step, inspired by grating couplers to control the light-matter interaction at material surfaces, we investigated the effect of anisotropic rough surfaces
We demonstrated a spectrally selective absorber surface made of Tungsten using an anisotropic Gaussian rough surface for high-temperature applications
Summary
Thermal solar [1,2,3], solar thermophotovoltaic [4], nuclear fusion [5,6,7], and aerospace applications [8] rely heavily on materials capable of operating at high temperatures. Tungsten has high absorption in the visible range, but its large real part of the dielectric constant leads to a high reflection in the infrared regime. This causes flat films to have 60% or less absorption [13].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
