Microstructural analysis of selective C/Al2O3/Al solar absorber surfaces

P. Konttinen, R. Kilpi, P. Lund

Research output: Contribution to journalArticleScientificpeer-review

15 Citations (Scopus)

Abstract

The elemental composition and geometrical structure of mechanically manufactured spectrally selective C/Al2O3/Al solar absorber surfaces were characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy, energy dispersive X-ray spectroscopy and optical microscopy. The XPS analysis revealed that the surface contains Al2O3 and C in graphite form. Optical microscopy confirmed that graphite forms inhomogeneous agglomerated clusters on the surface. The thickness of the clusters varies, the maximum measured thickness being in the range of 300 nm. A solar absorptance of 0.90 and a thermal emittance of 0.22 have been achieved so far. Increasing the graphite coverage and decreasing the graphite cluster thickness could increase the absorptance to greater than or equal to0.94 and lower the emittance. This could be achieved by altering the composition and the structure of the grinding pad used and by finding the suitable manufacturing parameters for the advanced pad. (C) 2002 Elsevier Science B.V. All rights reserved.

Original languageEnglish
Article numberPII S0040-6090(02)01141-0
Pages (from-to)24-30
Number of pages7
JournalThin Solid Films
Volume425
Issue number1-2
DOIs
Publication statusPublished - 3 Feb 2003
MoE publication typeA1 Journal article-refereed

Keywords

  • aluminium oxide
  • graphite
  • optical coatings
  • scanning electron microscopy
  • COATINGS
  • FILMS

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