Title
Multilayer front-sheet for solar modules with tuned color appearance
Author
Rooms, H.C.A.
Barbu, I.
Vroon, Z.A.E.P.
Meertens, R.
Vermeulen, B.
Publication year
2011
Abstract
The acceptance of solar cells in the built environment is partly dependent on the appearance of the solar modules. One aspect in the appearance is color. In most cases a solar cell itself reflects either blue or no color and will appear blackish. For the blue solar cells it is possible to tune the antireflection layer in such a way that a different color is reflected. We propose a front-sheet covered with a stack of thin layers consisting of high and low refractive index materials deposited from sol-gel onto PET foil such that only a particular wavelength range is reflected. We show through modeling that by alternating layers consisting of low refractive index layer (silica (SiO 2) and high reflection layer (silica-titania 25 mol% SiO2: 75 mol%TiO2) on PET foil such color reflection can be achieved. In modeling exercises the influence of the number of layers, thickness variations and angle of incidence on the reflected color are predicted as well as an estimated influence on the module efficiency. We show that with a four layer stack we can reach chroma values of 60 for green and 40 for red color in the CIELCH system. In experimental results we achieve a peak reflection of 41.7% with a band width of 90 nm while transmission is more than 90% for the other parts of the spectrum. © 2011 SPIE.
Subject
Mechatronics, Mechanics & Materials
TFT - Thin Film Technology
TS - Technical Sciences
Electronics
BIPV
CdTe
CIGS
Color
Front sheet
Reflection
Silicon
Solar
BIPV
CdTe
CIGS
Front sheet
Solar
Cadmium compounds
Film preparation
Light refraction
Nanostructured materials
Refractive index
Refractometers
Semiconducting silicon compounds
Silica
Silicon oxides
Thin films
Titanium dioxide
Color
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http://resolver.tudelft.nl/uuid:2a7285ca-7c94-4198-8908-afba1d5c324b
TNO identifier
443000
ISBN
780819487209
ISSN
0277-786X
Source
Thin Film Solar Technology III, 21-22 August 2011, San Diego, CA, USA. Conference code: 86935, 8110
Series
Proceedings of SPIE - The International Society for Optical Engineering
Article number
No.: 81100V
Document type
conference paper