uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Optical, thermal and structural characteristics of carbon nanoparticles embedded in ZnO and NiO as selective solar absorbers
Show others and affiliations
2008 (English)In: Solar Energy Materials and Solar Cells, ISSN 0927-0248, E-ISSN 1879-3398, Vol. 92, no 10, 1285-1292 p.Article in journal (Refereed) Published
Abstract [en]

Selective solar absorber coatings of carbon embedded in ZnO and NiO matrices on aluminium substrates have been fabricated by a sol-gel technique. Spectrophotometry was used to determine the solar absorptance and the thermal emittance of the composite coatings. The surface morphology of the samples was studied by scanning electron microscopy (SEM). Cross-sectional high-resolution transmission electron microscopy (X-HRTEM) was used to study the fine structure of the samples. Chemical composition analysis was done by energy dispersive spectroscopy (EDS) and electron energy loss spectroscopy (EELS). The crystal structure of ZnO and NiO samples was also investigated with an X-ray diffraction (XRD) technique. Samples were subjected to an accelerated ageing test for 95 h, with condensation at relative humidity of 95% and at a climate chamber temperature of 45 degrees C. The thermal emittances of the samples were 6% for the ZnO and 4% for the NiO matrix materials. The solar absorptances were 71% and 84% for ZnO and NiO samples, respectively. The SEM revealed a smooth featureless surface for both C-ZnO and C-NiO samples. Some C-NiO samples showed dentritic features. X-HRTEM, EDS and EELS studies revealed a nanometric grain size for both types of samples. The C-ZnO and C-NiO coatings contained amorphous carbon embedded in nanocrystalline ZnO and NiO matrices, respectively. Selected area electron diffraction (SAED) showed that a small amount of Ni grains of 30 nm diameter also existed in the NiO matrix. The accelerated ageing tests produced performance criterion (PC) values of 0.15 and 0.054 at 95 h for the C-ZnO and C-NiO samples, respectively. Based on these results, C-NiO samples proved to have better solar selectivity behaviour than the C-ZnO counterparts.

Place, publisher, year, edition, pages
2008. Vol. 92, no 10, 1285-1292 p.
Keyword [en]
selective solar absorbers, carbon nanoparticles, dielectric matrices
National Category
Engineering and Technology
URN: urn:nbn:se:uu:diva-109134DOI: 10.1016/j.solmat.2008.04.023ISI: 000258431300019OAI: oai:DiVA.org:uu-109134DiVA: diva2:248944
Available from: 2009-10-09 Created: 2009-10-09 Last updated: 2016-04-13Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Wäckelgård, Eva
By organisation
Applied Materials SciencesSolid State Physics
In the same journal
Solar Energy Materials and Solar Cells
Engineering and Technology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 426 hits
ReferencesLink to record
Permanent link

Direct link