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Highly Efficient Infrared Quantum Cutting in Tb 3+ −Yb 3+ Codoped Silicon Oxynitride for Solar Cell Applications
Author(s) -
An YongTao,
Labbé Christophe,
Cardin Julien,
Morales Magali,
Gourbilleau Fabrice
Publication year - 2013
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.201300186
Subject(s) - quantum efficiency , materials science , infrared , silicon oxynitride , silicon , photoluminescence , optoelectronics , solar cell , sputter deposition , energy conversion efficiency , sputtering , thin film , optics , nanotechnology , physics , silicon nitride
A high efficiency infrared quantum cutting effect in a Tb 3+ –Yb 3+ codoped silicon oxynitride system is demonstrated. The thin films are deposited on Si substrates by reactive magnetron co‐sputtering of a Si target topped with Tb 4 O 7 and Yb 2 O 3 chips under pure nitrogen plasma. The photoluminescence dynamics are investigated, revealing a quantum efficiency of this system at 980 nm up to 197% for the higher Yb 3+ concentration. Thus, via a cooperative transfer mechanism between Tb 3+ and Yb 3+ , an absorbed UV–visible photon gives rise to almost two emitted IR photons. Such a down‐conversion effect is demonstrated upon indirect excitation of energy donors, via defect states in the host matrix. These down‐converter films could be directly and easily integrated on top of the Si‐based solar cell to improve the photoelectric conversion efficiency at a lower cost. An evaluation of the additional external quantum efficiency is deduced from this optical system and found to be almost 2%.