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Aperiodic Metal‐Dielectric Multilayers as Highly Efficient Sunlight Reflectors
Author(s) -
JiménezSolano Alberto,
Anaya Miguel,
Calvo Mauricio E.,
AlconCamas Mercedes,
Alcañiz Carlos,
Guillén Elena,
Martínez Noelia,
Gallas Manuel,
Preussner Thomas,
EscobarGalindo Ramón,
Míguez Hernán
Publication year - 2017
Publication title -
advanced optical materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.89
H-Index - 91
ISSN - 2195-1071
DOI - 10.1002/adom.201600833
Subject(s) - aperiodic graph , materials science , dielectric , absorption (acoustics) , optoelectronics , optics , reflection (computer programming) , fabrication , sunlight , photovoltaic system , solar energy , computer science , physics , medicine , ecology , mathematics , alternative medicine , pathology , combinatorics , composite material , biology , programming language
The optimum reflection of the solar spectrum at well‐defined incident directions as well as its durability in time are, both, fundamental requirements of the optics of thermosolar and photovoltaic energy conversion systems. The stringent high performance needed for these applications implies that, almost exclusively, second face mirrors based on silver are employed for this purpose. Herein, the possibility to develop solar mirrors using other metals, such as copper and aluminum, is theoretically and experimentally analyzed. It is found that reflectors based on these inexpensive metals are capable of reflecting the full solar spectrum with efficiencies comparable to that of silver‐based reflectors. The designs herein proposed are based on aperiodic metal‐dielectric multilayers whose optimized configuration is chosen employing a code based on a genetic algorithm that allows selecting the best one among 10 8 tested reflectors. The use of metals with wider spectral absorption bands is compensated by the use of multilayered designs in which metal absorption is almost suppressed, as the analysis of the electric field intensity distribution demonstrates. The feasibility of the proposed mirrors is demonstrated by their actual fabrication by large area deposition techniques amenable for mass production.