Selective absorbers based on AlCuFe thin films

AlCuFe films of different thicknesses were ion beam sputter deposited onto substrates held at temperatures of 480-490 degrees C. Composition of the films was measured with elastic recoil detection and found to be Al62Cu25Fe13. X-ray diffraction of AlCuFe films approximate to 200 nm thick showed that these films consist of a mixture of quasicrystalline and crystalline phases. Selective absorbers were produced by deposition of sandwich systems of 50 nm Al2O3/10-12 nm AlCuFe/70 nm Al2O3 on a copper film on Al2O3 coated Si-wafers. A solar absorptance of 90% was achieved, while the near normal directional emittance measured af room temperature is about 2.5%. Optical constants and DC-resistivity data of the AlCuFe films are reported.