Christophe Ballif
École Polytechnique Fédérale de Lausanne
741 Papers
5.5K Citations
Christophe Ballif is an academic researcher from École Polytechnique Fédérale de Lausanne. The author has contributed to research in topics: Silicon & Amorphous silicon. The author has an hindex of 82, co-authored 696 publications. Previous affiliations of Christophe Ballif include Martin Luther University of Halle-Wittenberg & Swiss Center for Electronics and Microtechnology.
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Papers
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.
2.5K
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.
High-efficiency Silicon Heterojunction Solar Cells: A Review
Stefaan De Wolf,Antoine Descoeudres,Zachary C. Holman,Christophe Ballif +3 more
- 08 Mar 2012
TL;DR: Silicon heterojunction solar cells as mentioned in this paper consist of thin amorphous silicon layers deposited on crystalline silicon wafers, which enables energy conversion efficiencies above 20% at the industrial production level.
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.
584
Current Losses at the Front of Silicon Heterojunction Solar Cells
Zachary C. Holman,Antoine Descoeudres,L. Barraud,Fernando Zicarelli Fernandez,Johannes P. Seif,S. De Wolf,Christophe Ballif +6 more
TL;DR: In this paper, the current losses due to parasitic absorption in the indium tin oxide (ITO) and amorphous silicon (a-Si:H) layers at the front of silicon heterojunction solar cells are isolated and quantified.