Carbon-in-silica composite selective solar absorbers: A determination of composition and dielectric properties

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dc.contributor.authorKatumba G.
dc.contributor.authorForbes A.
dc.date.accessioned2011-05-15T16:00:21Z
dc.date.available2011-05-15T16:00:21Z
dc.date.issued2009
dc.description.abstractThe Bruggeman and Maxwell-Garnett effective medium approximations have been used widely to investigate optical properties of many different composite materials. In most cases, the effective medium approximation assumptions are based on random unit cell models in which some metal particles are embedded in a dielectric medium. The shapes of the embedded particles can be varied between spherical, ellipsoidal and cylindrical shapes. A new and interesting structure of connected short chains of completely amorphous carbon intermixed with short chains of silica at nanoscale level has been observed recently. A generalised Bergman representation based on an arbitrary spectral density function is currently applied on these carbon-in-silica samples with a reasonable success of fitting between experiment and theory. The curve-fitting procedure adopted here has resulted in information such as volume fraction of carbon relative to silica, percolation threshold, the thickness and effective dielectric function of the composite layer. © 2009 SPIE.
dc.description.versionConference Paper
dc.identifier.citationProceedings of SPIE - The International Society for Optical Engineering
dc.identifier.citation7410
dc.identifier.issn0277786X
dc.identifier.other10.1117/12.827960
dc.identifier.urihttp://hdl.handle.net/10019.1/11657
dc.subjectBruggeman effective medium approximation
dc.subjectComposite layer
dc.subjectCylindrical shapes
dc.subjectDielectric functions
dc.subjectDielectric medium
dc.subjectEffective Medium Approximation
dc.subjectEmbedded particles
dc.subjectMaxwell-Garnett
dc.subjectMetal particle
dc.subjectNano scale
dc.subjectNanoscale levels
dc.subjectPercolation thresholds
dc.subjectRandom unit cell
dc.subjectSelective solar absorber
dc.subjectSilica composites
dc.subjectSpectral density function
dc.subjectComposite materials
dc.subjectComposite micromechanics
dc.subjectCurve fitting
dc.subjectDielectric properties of solids
dc.subjectGarnets
dc.subjectMaxwell equations
dc.subjectNanostructured materials
dc.subjectOptical properties
dc.subjectSilica
dc.subjectSolar absorbers
dc.subjectSolar concentrators
dc.subjectSolar energy
dc.subjectSolar radiation
dc.subjectSolvents
dc.subjectSpectral density
dc.subjectAmorphous carbon
dc.titleCarbon-in-silica composite selective solar absorbers: A determination of composition and dielectric properties
dc.typeConference Paper
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