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Bjoern Niesen
Researcher at École Polytechnique Fédérale de Lausanne
Publications - 51
Citations - 9005
Bjoern Niesen is an academic researcher from École Polytechnique Fédérale de Lausanne. The author has contributed to research in topics: Perovskite (structure) & Silicon. The author has an hindex of 31, co-authored 51 publications receiving 7228 citations. Previous affiliations of Bjoern Niesen include Katholieke Universiteit Leuven & University of Basel.
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Journal ArticleDOI
Organometallic Halide Perovskites: Sharp Optical Absorption Edge and Its Relation to Photovoltaic Performance
Stefaan De Wolf,Jakub Holovsky,Soo-Jin Moon,Philipp Löper,Bjoern Niesen,Martin Ledinsky,Martin Ledinsky,F.-J. Haug,Jun-Ho Yum,Christophe Ballif +9 more
TL;DR: Using highly sensitive photothermal deflection and photocurrent spectroscopy, the absorption spectrum of CH3NH3PbI3 perovskite thin films at room temperature is measured, finding a high absorption coefficient with particularly sharp onset and a compositional change of the material.
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Fully textured monolithic perovskite/silicon tandem solar cells with 25.2% power conversion efficiency.
Florent Sahli,Jérémie Werner,Brett A. Kamino,Matthias Bräuninger,Raphael Monnard,Bertrand Paviet-Salomon,Loris Barraud,Laura Ding,Juan J. Diaz Leon,Davide Sacchetto,Gianluca Cattaneo,Matthieu Despeisse,Mathieu Boccard,Sylvain Nicolay,Quentin Jeangros,Bjoern Niesen,Christophe Ballif +16 more
TL;DR: An optimized two-step deposition process allows the formation of uniform layers of metal halide perovskites on textured silicon layers, enabling tandem silicon/perovskite solar cells with improved optical design and efficiency.
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Interpretation and evolution of open-circuit voltage, recombination, ideality factor and subgap defect states during reversible light-soaking and irreversible degradation of perovskite solar cells
Wolfgang Tress,Mozhgan Yavari,Konrad Domanski,Pankaj Yadav,Bjoern Niesen,Juan Pablo Correa Baena,Anders Hagfeldt,Michael Graetzel +7 more
TL;DR: In this paper, the authors analyzed perovskite solar cells with different architectures (planar, mesoporous, HTL-free), employing temperature dependent measurements (currentvoltage, light intensity, electroluminescence) of the ideality factor to identify dominating recombination processes that limit the open-circuit voltage (Voc).
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Complex Refractive Index Spectra of CH3NH3PbI3 Perovskite Thin Films Determined by Spectroscopic Ellipsometry and Spectrophotometry
Philipp Löper,Michael Stuckelberger,Bjoern Niesen,Jérémie Werner,Miha Filipič,Soo-Jin Moon,Jun-Ho Yum,Marko Topič,Stefaan De Wolf,Christophe Ballif +9 more
TL;DR: The complex refractive index of planar CH3NH3PbI3 thin films at room temperature is investigated by variable angle spectroscopic ellipsometry and spectrophotometry and results agree well with previously reported data of the absorption coefficient and are consistent with Kramers-Kronig transformations.
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Efficient Monolithic Perovskite/Silicon Tandem Solar Cell with Cell Area >1 cm2
Jérémie Werner,Ching Hsun Weng,Arnaud Walter,L. Fesquet,Johannes P. Seif,Stefaan De Wolf,Bjoern Niesen,Christophe Ballif +7 more
TL;DR: A low-temperature process for semitransparent perovskite/crystalline silicon tandem solar cells is presented, yielding efficiencies up to 14.5%, and the effects of varying the intermediate recombination layer and hole transport layer thicknesses on tandem cell photocurrent generation are presented, experimentally and by transfer matrix simulations.