Structure and optical properties of pulsed sputter deposited CrxOy∕Cr∕Cr2O3 solar selective coatings

Spectrally selective CrxOy∕Cr∕Cr2O3 multilayer absorber coatings were deposited on copper (Cu) substrates using a pulsed sputtering system. The Cr targets were sputtered using asymmetric bipolar-pulsed dc generators in Ar+O2 and Ar plasmas to deposit a CrxOy (bottomlayer)∕Cr∕Cr2O3 (top layer) coating. The compositions and thicknesses of the individual component layers have been optimized to achieve high absorptance (0.899–0.912) and low emittance (0.05–0.06). The x-ray diffraction data in thin film mode showed that the CrxOy∕Cr∕Cr2O3 coating consists of an amorphous phase; the Raman data of the coating, however, showed the presence of A1g and Eg modes, characteristic of Cr2O3. The x-ray photoelectron spectroscopy (XPS) data from near-surface region of the absorber suggested that the chemical state of Cr was in the form of Cr3+ and no phases of CrO2 and CrO3 were present. The experimental spectroscopic ellipsometric data have been fitted with theoretical models to derive the dispersion of the optical const...

[1]  Jun-Sik Cho,et al.  Chemical reaction of sputtered Cu film with PI modified by low energy reactive atomic beam , 2006 .

[2]  H. Trodahl,et al.  Raman spectroscopy of nanocrystalline and amorphous GaN , 2005 .

[3]  N. Rosman,et al.  In situ Raman monitoring of chromium oxide scale growth for stress determination , 2001 .

[4]  E. Weber,et al.  Raman spectroscopy of intrinsic defects in electron and neutron irradiated GaAs , 1985 .

[5]  H. Barshilia,et al.  Spectroscopic ellipsometric characterization of TiAlN/TiAlON/Si3N4 tandem absorber for solar selective applications , 2008 .

[6]  K. Kishi,et al.  Preparation of ultrathin chromium oxide films on Cu(110) investigated by XPS and LEED , 1998 .

[7]  K. H. Jolliffee.  Optical properties of thin solid films , 1954 .

[8]  A. Stierle,et al.  Oxidation induced roughening during Cr2O3(0001) growth on Cr(110) , 1997 .

[9]  Susumu Ninomiya,et al.  Optical properties of wurtzite CdS , 1995 .

[10]  R. Jeanloz,et al.  Raman spectroscopy and x-ray diffraction of phase transitions in Cr 2 O 3 to 61 GPa , 2004 .

[11]  J. Mougin,et al.  High-pressure study of Cr2O3 obtained by high-temperature oxidation by X-ray diffraction and Raman spectroscopy , 2001 .

[12]  P. Sebastián,et al.  Retention of the high optical absorptance in thermally aged black chrome on variably sensitized Cu , 1997 .

[13]  K. Chopra,et al.  Stability investigations of a chemically converted textured black copper selective surface , 1989 .

[14]  B. Window,et al.  Applications of thin graded-index films to solar absorbers. , 1977, Applied optics.

[15]  H. Barshilia,et al.  Superhard nanocomposite coatings of TiN/Si3N4 prepared by reactive direct current unbalanced magnetron sputtering , 2006 .

[16]  E. Bucher,et al.  Performance and stability of some new high-temperature selective absorber systems based on metal/dielectric multilayers , 1994 .

[17]  P. Marcus,et al.  XPS, LEED and STM study of thin oxide films formed on Cr(110) , 2000 .

[18]  E. Palik.  Handbook of Optical Constants of Solids , 1997 .

[19]  David R. Mills,et al.  Very low‐emittance solar selective surfaces using new film structures , 1992 .

[20]  S. Deng,et al.  Activity and characterization of modified Cr2O3/ZrO2 nano-composite catalysts for oxidative dehydrogenation of ethane to ethylene with CO2 , 2007 .

[21]  Alex Ignatiev,et al.  Refinement of solar absorbing black chrome microstructure and its relationship to optical degradation mechanisms , 1980 .

[22]  J. Coey,et al.  Raman spectroscopy of ferromagnetic CrO 2 , 1999 .

[23]  A. Atkinson.  Transport processes during the growth of oxide films at elevated temperature , 1985 .

[24]  H. Barshilia,et al.  TiAlN∕TiAlON∕Si3N4 tandem absorber for high temperature solar selective applications , 2006 .

[25]  S. Thakur,et al.  Reactive electron beam evaporation of gadolinium oxide optical thin films for ultraviolet and deep ultraviolet laser wavelengths , 2003 .

[26]  John C. C. Fan,et al.  Selective black absorbers using rf‐sputtered Cr2O3/Cr cermet films , 1977 .

[27]  D. Bhattacharyya,et al.  Spectroscopic ellipsometric study on dispersion of optical constants of Gd2O3 films , 2005 .

[28]  David A. Brown,et al.  The infrared and Raman spectra of chromium (III) oxide , 1968 .

[29]  Wmm Erwin Kessels,et al.  Determining the material structure of microcrystalline silicon from Raman spectra , 2003 .

[30]  Chromium-based thin sputtered composite coatings for solar thermal collectors , 2002 .

[31]  M. Köhl,et al.  Accelerated ageing test procedures for selective absorber coatings including lifetime estimation and comparison with outdoor test results , 1989 .

[32]  H. Barshilia,et al.  Raman spectroscopy studies on the thermal stability of TiN, crN, TiAlN coatings and nanolayered TiN/CrN, TiAlN/CrN multilayer coatings , 2004 .

[33]  F. Lévy,et al.  Characterization of sputter-deposited chromium oxide thin films , 1999 .

[34]  Wanxin Sun,et al.  Phase control of chromium oxide in selective microregions by laser annealing , 2003 .

[35]  S. Adachi,et al.  Model dielectric function for amorphous semiconductors , 2002 .

[36]  I. J. Hall,et al.  Black chrome solar selective coatings optimized for high temperature applications , 1982 .