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Title:
 
Reflective Multilayer Coatings with Dielectric Barriers for High Concentration Photovoltaics
 
Author(s):
 
J.A. Sánchez-García, M. Machado, C. Prieto, C. Agustín, M. Brizuela, I. Braceras, R. Alonso, F.J. Cano, O. Zubillaga
 
Keywords:
 
Magnetron Sputtering, Durability, Optical Properties, Concentrator, First-Surface Mirror
 
Topic:
 
MATERIAL STUDIES, NEW CONCEPTS, ULTRA-HIGH EFFICIENCY AND SPACE TECHNOLOGY
Subtopic: Terrestrial Concentrator Systems
Event: 28th European Photovoltaic Solar Energy Conference and Exhibition
Session: 1CV.6.33
 
Pages:
 
625 - 627
ISBN: 3-936338-33-7
Paper DOI: 10.4229/28thEUPVSEC2013-1CV.6.33
 
Price:
 
 
0,00 EUR
 
Document(s): paper
 

Abstract/Summary:


First-surface mirrors based on reflective multilayer coatings on polycarbonate substrate have been developed and tested for use as primary optics in high concentration photovoltaic (HCPV) systems. These coatings must provide high reflectance properties over a wavelength range between 300 and 1800 nm, where multijunction cells are significantly active for photovoltaic (PV) generation. Additionally, a good ageing resistance to UV radiation and high humidity/temperature conditions has to be achieved. Silver, aluminium and Ticusil® (titanium, copper and silver alloy) films were developed and protected with either SiO2 or Si3N4 layers on polycarbonate substrate. The multilayer mirrors were previously designed using CODE software. Reflective and protective films were grown by DC and by reactive RF sputtering, respectively. The durability of the developed mirrors was evaluated through damp heat and UV exposure tests. An integrated total solar reflectance of 90% was obtained with Al/SiO2 multilayers, without significant performance loss after damp-heat and UV tests. Highest initial specular reflectance values up to 95% and 89% were obtained for silver-based coatings before and after damp-heat tests. In the case of aluminium, only a slight decrease less than 1% was observed from initial 88%. The reflectance of Ticusil®/Si3N4 mirrors was initially lower than that of Al and Ag mirrors.