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Sylvain Nicolay

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Related publications (66)

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Hole-Selective Front Contact Stack Enabling 24.1%-Efficient Silicon Heterojunction Solar Cells

Christophe Ballif, Sylvain Nicolay, Mathieu Gérard Boccard, Matthieu Despeisse, Jean Cattin, Luca Massimiliano Antognini, Vincent Philippe Paratte, Laurie-Lou Senaud, Bertrand Yves Paul Paviet-Salomon, Minh Truong, Jan Haschke, Julie Amandine Dreon

The window-layer stack limits the efficiency of both-side-contacted silicon heterojunction solar cells. We discuss here the combination of several modifications to this stack to improve its optoelectronic performance. These include the introduction of a na ...

2020

Sputter Deposition Technology For Al((1-X))Sc(X)N Films With High Sc Concentration

Paul Muralt, Sylvain Nicolay, Gabriel Christmann, Stefan Mertin

Aluminium scandium nitride (Al1-xScxN) with its strongly enhanced piezoelectric response is the upcoming piezoelectric material of choice in next generation RF filters, sensors, actuators and energy harvesting devices. This paper will concentrate on the de ...

IEEE2017

Sputtered rear electrode with broadband transparency for perovskite solar cells

Christophe Ballif, Guy Joseph Günter Dubuis, Sylvain Nicolay, Soo-Jin Moon, Arnaud Walter, Stefaan De Wolf, Jérémie Werner, Monica Morales Masis, Björn Niesen, Philipp Friedrich Hermann Löper

Due to their high efficiencies combined with simple and cost-effective device fabrication, perovskite solar cells are promising candidates as top cells in tandem devices. For this application, the perovskite solar cell must be highly transparent at near-in ...

Elsevier2015

ITO/MoOx/a-Si:H(i) Hole-Selective Contacts for Silicon Heterojunction Solar Cells: Degradation Mechanisms and Cell Integration

Christophe Ballif, Aïcha Hessler-Wyser, Antoine Descoeudres, Sylvain Nicolay, Quentin Thomas Jeangros, Gabriel Christmann, Davide Sacchetto, Matthieu Despeisse, Loris Barraud, Jonas Geissbühler

Molybdenum oxide is an efficient hole collector for silicon solar cells. However, its optoelectronic properties deteriorate during cell manufacturing. To assess this issue, the optoelectronic properties and microstructure of molybdenum oxide-based hole con ...

2017

Nitride-based heterostructures grown by MOCVD for near- and mid-infrared intersubband transitions

Jean-François Carlin, Marc Ilegems, Nicolas Grandjean, Raphaël Butté, Eric Feltin, Sylvain Nicolay

Intersubband (lSB) optical absorption in different nitride-based heterostructures grown by metal-organic chemical vapour deposition (MOCVD) is reported. The role of indium in AlInN/GaN multi-quantum wells (MQWs) is investigated. At high concentration (15%) ...

Wiley2007

Light-induced performance increase of silicon heterojunction solar cells

Christophe Ballif, Antoine Descoeudres, Jacques Levrat, Sylvain Nicolay, Gabriel Christmann, Stefaan De Wolf, Matthieu Despeisse

Silicon heterojunction solar cells consist of crystalline silicon (c-Si) wafers coated with doped/intrinsic hydrogenated amorphous silicon (a-Si:H) bilayers for passivating-contact formation. Here, we unambiguously demonstrate that carrier injection either ...

American Institute of Physics2016

Advanced method for electrical characterization of carrier-selective passivating contacts using transfer-length-method measurements under variable illumination

Christophe Ballif, Antoine Descoeudres, Sylvain Nicolay, Gabriel Christmann, Mathieu Gérard Boccard, Matthieu Despeisse, Jonas Geissbühler, Laurie-Lou Senaud, Bertrand Yves Paul Paviet-Salomon

2021

Lattice-matched GaN-InAlN waveguides at lambda=1.55 mu m grown by metal-organic vapor phase epitaxy

Jean-François Carlin, Nicolas Grandjean, Eric Feltin, Sylvain Nicolay

We report on the demonstration of low-loss, single-mode GaN-InAlN ridge waveguides (WGs) at fiber-optics telecommunication wavelengths. The structure grown by metal-organic vapor phase epitaxy contains AlInN cladding layers lattice-matched to GaN. For slab ...

2008

Back-Contacted Silicon Heterojunction Solar Cells: Optical-Loss Analysis and Mitigation

Christophe Ballif, Antoine Descoeudres, Sylvain Nicolay, Stefaan De Wolf, Matthieu Despeisse, Loris Barraud, Andrea Tomasi, Bertrand Yves Paul Paviet-Salomon

We analyze the optical losses that occur in interdigitated back-contacted amorphous/crystalline silicon heterojunction solar cells. We show that in our devices, the main loss mechanisms are similar to those of two-side contacted heterojunction solar cells. ...

Ieee-Inst Electrical Electronics Engineers Inc2015

22.8% full-area bifacial n-PERT solar cells with rear side sputtered poly-Si (n) passivating contact

Christophe Ballif, Sylvain Nicolay, Bertrand Yves Paul Paviet-Salomon, Andrea Ingenito, Sofia Libraro

High-temperature compatible passivating contacts based on phosphorus doped polysilicon (poly-Si(n)) on a thin silicon oxide, employed on the rear side of bifacial n-PERT like solar cells provide an efficiency increase while being compatible with current ph ...

ELSEVIER2023

Nanoscale Analysis by EFTEM and FIB-Tomography for Optimization of Thin-Film Silicon Solar Cells

Christophe Ballif, Marco Cantoni, Peter Cuony, Sylvain Nicolay, Duncan Thomas Lindsay Alexander

Cambridge, Cambridge University Press2010

Optical properties of anodically degraded ZnO

Christophe Ballif, Sylvain Nicolay

We discuss the optical properties of non-degraded and anodically degraded boron-doped zinc oxide (ZnO:B) deposited by low-pressure chemical vapour deposition on soda-lime glass. The optical model used to simulate the infrared reflectance in the wavelength ...

American Institute of Physics2014

Complex Refractive Indices of Cesium–Formamidinium-Based Mixed-Halide Perovskites with Optical Band Gaps from 1.5 to 1.8 eV

Christophe Ballif, Sylvain Nicolay, Quentin Thomas Jeangros, Gabriel Christmann, Arnaud Walter, Jérémie Werner, Florent Sahli, Björn Niesen, Gizem Nogay, Philipp Friedrich Hermann Löper, Matthias Wolfgang Bräuninger, Peter Joseph Fiala, Chien-Jen Yang

Cesium-formamidinium-based mixed-halide perovskite materials with optical band gaps ranging from 1.5 to 1.8 eV are investigated by variable-angle spectroscopic ellipsometry. The determined complex refractive indices are shown to depend on the fabrication p ...

2018

Simple processing of back-contacted silicon heterojunction solar cells using selective-area crystalline growth

Christophe Ballif, Antoine Descoeudres, Sylvain Nicolay, Quentin Thomas Jeangros, Gabriel Christmann, Stefaan De Wolf, Matthieu Despeisse, Loris Barraud, Johannes Peter Seif, Andrea Tomasi, Bertrand Yves Paul Paviet-Salomon, Jan Haschke

For crystalline-silicon solar cells, voltages close to the theoretical limit are nowadays readily achievable when using passivating contacts. Conversely, maximal current generation requires the integration of the electron and hole contacts at the back of t ...

Nature Publishing Group2017

Organic-inorganic halide perovskite/crystalline silicon four-terminal tandem solar cells

Christophe Ballif, Sylvain Nicolay, Jun Ho Yum, Soo-Jin Moon, Stefaan De Wolf, Björn Niesen, Martin Ledinsky

Tandem solar cells constructed from a crystalline silicon (c-Si) bottom cell and a low-cost top cell offer a promising way to ensure long-term price reductions of photovoltaic modules. We present a four-terminal tandem solar cell consisting of a methyl amm ...

Royal Society of Chemistry2015

Increasing Polycrystalline Zinc Oxide Grain Size by Control of Film Preferential Orientation

Christophe Ballif, Aïcha Hessler-Wyser, Sylvain Nicolay, Arthur Brian Aebersold, Cécile Hébert, Duncan Thomas Lindsay Alexander, Lorenzo Fanni, Monica Morales Masis

We investigate the structural evolution of polycrystalline zinc oxide films grown by low pressure metal-organic chemical vapor deposition. The goal is to achieve larger grains-leading to higher charge carrier mobility from lower grain boundary density-by c ...

American Chemical Society2015

22.5% efficient silicon heterojunction solar cell with molybdenum oxide hole collector

Christophe Ballif, Aïcha Hessler-Wyser, Sylvain Nicolay, Stefaan De Wolf, Matthieu Despeisse, Jérémie Werner, Loris Barraud, Andrea Tomasi, Björn Niesen

Substituting the doped amorphous silicon films at the front of silicon heterojunction solar cells with wide-bandgap transition metal oxides can mitigate parasitic light absorption losses. This was recently proven by replacing p-type amorphous silicon with ...

American Institute of Physics2015

Interdigitated back contact silicon heterojunction solar cells featuring an interband tunnel junction enabling simplified processing

Christophe Ballif, Antoine Descoeudres, Benjamin Strahm, Antonin Faes, Sylvain Nicolay, Quentin Thomas Jeangros, Gabriel Christmann, Stefaan De Wolf, Matthieu Despeisse, Loris Barraud, Jonas Geissbühler, Johannes Peter Seif, Andrea Tomasi, Bertrand Yves Paul Paviet-Salomon

This paper reports on the development of an innovative back-contacted crystalline silicon solar cell with passivating contacts featuring an interband tunnel junction at its electron-collecting contacts. In this novel architecture, named "tunnel-IBC", both ...

2018

Hybrid sequential deposition process for fully textured perovskite/silicon tandem solar cells

Christophe Ballif, Laura Ding, Sylvain Nicolay, Quentin Thomas Jeangros, Soo-Jin Moon, Arnaud Walter, Davide Sacchetto, Mathieu Gérard Boccard, Matthieu Despeisse, Jérémie Werner, Florent Sahli, Loris Barraud, Raphaël Monnard, Monica Morales Masis, Gianluca Cattaneo, Bertrand Yves Paul Paviet-Salomon, Björn Niesen, Gizem Nogay, Oscar Esteban Rucavado Leandro, Matthias Wolfgang Bräuninger, Peter Joseph Fiala, Chien-Jen Yang, Fan Fu

Tandem solar cells that feature a high-bandgap perovskite cell on top of a lower bandgap silicon cell have the potential to reach efficiencies > 30%. Here, we present a versatile hybrid deposition method that yields conformal perovskite cells directly on t ...

IEEE2018

Progression towards high efficiency perovskite solar cells via optimisation of the front electrode and blocking layer

Christophe Ballif, Sylvain Nicolay, Soo-Jin Moon, Arnaud Walter, Davide Sacchetto, Björn Niesen, Matthias Wolfgang Bräuninger

The effects of a fluorine doped tin oxide (FTO) electrode, titanium dioxide (TiO2-x) blocking layer (BL) and perovskite (methyl ammonium lead triiodide) preparation on the overall properties of the photovoltaic cells have been studied. The FTO electrode wa ...

Royal Society of Chemistry2016