The optical properties of sputtered composite of Al-AlN
2006 (English)In: Solar Energy Materials and Solar Cells, ISSN 0927-0248, E-ISSN 1879-3398, Vol. 90, no 13, 1861-1874 p.Article in journal (Refereed) Published
Optical constants n and k have been determined for aluminum-aluminum nitride composite in a reactive gas flow from zero to a flow giving stoichiometric nitride. A method using a dielectric function model was applied for each component in the Bruggeman equation to fit the experimental reflectance and transmittance spectra in the wavelength range of 0.3-2.5 mu m. The refractive index of aluminum-aluminum nitride showed a maximum as the reactive gas increased. The extinction coefficient, on the other hand, decreased with increased reactive gas flow. The determined optical properties were then used to design a multilayer selective surface for solar thermal applications. Two absorbing layers with a graded feature plus an anti-reflection layer resulted in a high calculated solar absorptance of 0.97. The optimized metal content corresponds to the composite around the maximum refractive index. A solar absorptance of 0.96 was reached for experimentally prepared surfaces according to the theoretical prediction.
Place, publisher, year, edition, pages
2006. Vol. 90, no 13, 1861-1874 p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:uu:diva-95474DOI: 10.1016/j.solmat.2005.11.006ISI: 000238594000001OAI: oai:DiVA.org:uu-95474DiVA: diva2:169698