Title:
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Understanding light trapping by resonant coupling to guided modes and the importance of the mode profile
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Author:
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Beck, Fiona J.; Stavrinadis, Alexandros; Lasanta, Tania; Szczepanick, John-Paul; Konstantatos, Gerasimos
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Other authors:
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Universitat Politècnica de Catalunya. Institut de Ciències Fotòniques |
Abstract:
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We present a simple conceptual model describing the absorption
enhancement provided by diffraction gratings due to resonant coupling to
guided modes in a multi-layered structure. In doing so, we provide insight
into why certain guided modes are more strongly excited than others and
demonstrate that the spatial overlap of the mode profile with the grating is
important. The model is verified by comparison to optical simulations and
experimental measurements. We fabricate metal nanoparticle gratings
integrated as back contacts in solution-processed PbS colloidal quantum dot
photodiodes. The measured photocurrent at the target wavelength is
enhanced by 250%, with reference to planar devices, due to resonant
coupling to guided modes with strong spatial overlap with the gratings. In
comparison, resonant coupling to weakly overlapping modes results in a
25% increase at the same wavelength. |
Abstract:
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Peer Reviewed |
Subject(s):
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-Optics -light trapping -Òptica |
Rights:
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Attribution-NonCommercial-NoDerivs 3.0 Spain
http://creativecommons.org/licenses/by-nc-nd/3.0/es/ |
Document type:
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Article - Published version Article |
Published by:
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OSA
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