Optimization of SiO{sub 2}-TiN{sub x}O{sub y}-Cu interference absorbers: Numerical and experimental results

Book · Fri Dec 31 04:00:00 EST 1993

OSTI ID:201328

Lazarov, M; Sizmann, R ^[1]; Frei, U ^[2]

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1. Ludwig-Maximilians Univ., Muenchen (Germany). Sektion Physik
2. Solarenergie Pruef- und Forschungsstelle Technikum Rapperswil (Switzerland)

SiO{sub 2}-TiN{sub x}O{sub y}-Cu absorbers were prepared with activated reactive evaporation (ARE). The deposition parameters for the ARE process were adjusted according to the results of the numerical optimizations by a genetic algorithm. The authors present spectral reflectance, calorimetric and grazing incidence X-ray reflection (GXR) measurements. Best coatings for applications as selective absorber in the range of T = 100--200 C exhibit a solar absorptance of 0.94 and a near normal emittance of 0.044 at 100 C. This emittance is correlated with a hemispherical emittance of 0.061 obtained from calorimetric measurements at 200 C. First results on lifetime studies show that the coatings are thermally stable under vacuum up to 400 C. The SiO{sub 2} film passivates the absorber, a substantial slow down of degradation in dry air is observed. The tests demonstrate that the coating will withstand break down in cooling fluid and vacuum if mounted in an evacuated collector.

• OSTI ID: 201328
• Report Number(s): CONF-930722--; ISBN 0-8194-1266-X
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
ANTIREFLECTION COATINGS
COPPER
EVACUATED COLLECTORS
EXPERIMENTAL DATA
FABRICATION
LAYERS
PERFORMANCE
PERFORMANCE TESTING
SERVICE LIFE
SILICON OXIDES
SOLAR ABSORBERS
SPECTRALLY SELECTIVE SURFACES
THEORETICAL DATA
TITANIUM NITRIDES
TITANIUM OXIDES