2024-03-29T00:20:42Zhttps://gredos.usal.es/oai/requestoai:gredos.usal.es:10366/1386192022-02-07T15:42:08Zcom_10366_138605com_10366_4512com_10366_3823col_10366_138606
2018-10-16T07:45:40Z
urn:hdl:10366/138619
On the Effect of Thin Film Growth Mechanisms on the Specular Reflectance of Aluminium Thin Films Deposited via Filtered Cathodic Vacuum Arc
Rincón-Llorente, Gonzalo
Heras Pérez, Irene
Guillén, Elena
Schumann, Erik
Krauser, Matthias
Escobar-Galindo, Ramón
Surface engineering
Filtered cathodic vacuum arc
Total and specular reflectance
Thin film deposition conditions
Structural characterisation
[EN]The optimisation of the specular reflectance of solar collectors is a key parameter to
increase the global yield of concentrated solar power (CSP) plants. In this work, the influence of
filtered cathodic vacuum arc deposition parameters, particularly working pressure and deposition
time, on the specular and diffuse reflectance of aluminium thin films, was studied. Changes in
specular reflectance, measured by ultraviolet–visible and near-infrared spectroscopy (UV-vis-NIR)
spectrophotometry, were directly correlated with thin film elemental concentration depth profiles,
obtained by Rutherford backscattering spectrometry (RBS), and surface and cross-sectional
morphologies as measured by scanning electron microscopy (SEM) and profilometry. Finally, atomic
force microscopy (AFM) provided information on the roughness and growth mechanism of the films.
The two contributions to the total reflectance of the films, namely diffuse and specular reflectance,
were found to be deeply influenced by deposition conditions. It was proven that working pressure
and deposition time directly determine the predominant factor. Specular reflectance varied from 12
to 99.8% of the total reflectance for films grown at the same working pressure of 0.1 Pa and with
different deposition times. This transformation could not be attributed to an oxidation of the films
as stated by RBS, but was correlated with a progressive modification of the roughness, surface, and
bulk morphology of the samples over the deposition time. Hence, the evolution in the final optical
properties of the films is driven by different growth mechanisms and the resulting microstructures.
In addition to the originally addressed CSP applications the potential of the developed aluminium
films for other application rather than CSP, such as, for example, reference material for spectroscopic
diffuse reflectance measurements, is also discussed]
2018-10-16T07:45:40Z
2018-10-16T07:45:40Z
2018-09-13
info:eu-repo/semantics/article
Rincón-Llorente, G.; Heras, I.; Guillén Rodríguez, E.; Schumann, E.; Krause, M.; Escobar-Galindo, R. (2018). On the Effect of Thin Film Growth Mechanisms on the Specular Reflectance of Aluminium Thin Films Deposited via Filtered Cathodic Vacuum Arc. Coatings, 8, 321.
2079-6412
http://hdl.handle.net/10366/138619
10.3390/coatings8090321
eng
https://doi.org/10.3390/coatings8090321
http://creativecommons.org/licenses/by-nc-nd/4.0/
info:eu-repo/semantics/openAccess
Attribution-NonCommercial-NoDerivs 4.0 International
MDPI