Publications by Jérémie Werner

Multimodal Microscale Imaging of Textured Perovskite-Silicon Tandem Solar Cells

Christophe Ballif, Quentin Thomas Jeangros, Jérémie Werner, Florent Sahli, Chien-Jen Yang, Fan Fu, Alan Richard Bowman

Halide perovskite/crystalline silicon (c-Si) tandem solar cells promise power conversion efficiencies beyond the limits of single-junction cells. However, the local light-matter interactions of the perovskite material embedded in this pyramidal multijuncti ...

AMER CHEMICAL SOC2021

Effects of X-rays on Perovskite Solar Cells

Christophe Ballif, Yun Luo, Michael Elias Stückelberger, Jérémie Werner, Björn Niesen, Xueying Li

Synchrotron micro- and nanoprobe beamlines have demonstrated great potential to advance photovoltaic devices. Most importantly, their small X-ray spot size has enabled the direct correlation of electrical performance with elemental composition at subgrain ...

AMER CHEMICAL SOC2020

I-2 vapor-induced degradation of formamidinium lead iodide based perovskite solar cells under heat-light soaking conditions

Christophe Ballif, Sylvain Nicolay, Quentin Thomas Jeangros, Adriana Paracchino, Jérémie Werner, Léo Duchêne, Peter Joseph Fiala, Fan Fu

Over the last years, the operational stability of perovskite solar cells has been significantly improved by compositional engineering, interface modification, and improved encapsulation techniques. However, irreversible degradation is still ubiquitously ob ...

2019

25.1%-Efficient Monolithic Perovskite/Silicon Tandem Solar Cell Based on a p-type Monocrystalline Textured Silicon Wafer and High-Temperature Passivating Contacts

Christophe Ballif, Quentin Thomas Jeangros, Franz-Josef Haug, Mathieu Gérard Boccard, Matthieu Despeisse, Jérémie Werner, Florent Sahli, Gizem Nogay, Andrea Ingenito

2019

Solar Water Splitting with Perovskite/Silicon Tandem Cell and TiC-Supported Pt Nanocluster Electrocatalyst

Christophe Ballif, Michael Graetzel, Shaik Mohammed Zakeeruddin, Quentin Thomas Jeangros, Jérémie Werner, Florent Sahli, Jingshan Luo, Dan Ren, Jing Gao

Developing efficient, stable, and cost-effective photosystems to split water into hydrogen and oxygen using sunlight is of paramount importance for future production of fuels and chemicals from renewable sources. However, the high cost of current systems l ...

2019

Fully textured monolithic perovskite/silicon tandem solar cells with 25.2% power conversion efficiency

Christophe Ballif, Laura Ding, Sylvain Nicolay, Quentin Thomas Jeangros, Davide Sacchetto, Mathieu Gérard Boccard, Matthieu Despeisse, Jérémie Werner, Florent Sahli, Loris Barraud, Raphaël Monnard, Gianluca Cattaneo, Bertrand Yves Paul Paviet-Salomon, Björn Niesen, Matthias Wolfgang Bräuninger

Tandem devices combining perovskite and silicon solar cells are promising candidates to achieve power conversion efficiencies above 30% at reasonable costs. State-of-the-art monolithic two-terminal perovskite/silicon tandem devices have so far featured sil ...

2018

Toward Annealing-Stable Molybdenum-Oxide-Based Hole-Selective Contacts For Silicon Photovoltaics

Christophe Ballif, Stefaan De Wolf, Mathieu Gérard Boccard, Jérémie Werner, Jonas Geissbühler, Monica Morales Masis, Philipp Friedrich Hermann Löper, Oscar Esteban Rucavado Leandro, Stephanie Essig, Julie Amandine Dreon

Molybdenum oxide (MoOX) combines a high work function with broadband optical transparency. Sandwiched between a hydrogenated intrinsic amorphous silicon passivation layer and a transparent conductive oxide, this material allows a highly efficient hole‐sele ...

2018

Design of perovskite/crystalline-silicon monolithic tandem solar cells

Christophe Ballif, Jérémie Werner, Beat Ruhstaller, Björn Niesen

2018

Perovskite/Silicon Tandem Solar Cells: Toward Affordable Ultra-High Efficiency Photovoltaics ?

Jérémie Werner

Nowadays the photovoltaics market is dominated by crystalline silicon solar cells, which are approaching their theoretical efficiency limit. Novel solutions have to be found for photovoltaics to further enhance its competitiveness with other energy sources ...

EPFL2018

Perovskite/Perovskite/Silicon Monolithic Triple-Junction Solar Cells with a Fully Textured Design

Christophe Ballif, Sylvain Nicolay, Quentin Thomas Jeangros, Arnaud Walter, Jérémie Werner, Florent Sahli, Björn Niesen, Fan Fu

High efficiency triple-junction solar cells are currently made of III−V semiconductors using expensive deposition methods. Perovskite/perovskite/silicon monolithic triple-junction solar cells could be a lower-cost alternative as no epitaxial growth is requ ...

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

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

Charge Collection in Hybrid Perovskite Solar Cells: Relation to the Nanoscale Elemental Distribution

Christophe Ballif, Michael Elias Stückelberger, Jérémie Werner, Björn Niesen

Unveiling the correlation between elemental composition, Fermi-level splitting, and charge collection in perovskite solar cells (PSCs) when exposed to different environments is crucial to understanding the origin of defects. This will enable defect enginee ...

Ieee-Inst Electrical Electronics Engineers Inc2017

Improved Optics in Monolithic Perovskite/Silicon Tandem Solar Cells with a Nanocrystalline Silicon Recombination Junction

Christophe Ballif, Aïcha Hessler-Wyser, Sylvain Nicolay, Quentin Thomas Jeangros, Stefaan De Wolf, Matthieu Despeisse, Jérémie Werner, Florent Sahli, Loris Barraud, Raphaël Monnard, Johannes Peter Seif, Andrea Tomasi, Bertrand Yves Paul Paviet-Salomon, Björn Niesen, Matthias Wolfgang Bräuninger

Perovskite/silicon tandem solar cells are increasingly recognized as promi-sing candidates for next-generation photovoltaics with performance beyond the single-junction limit at potentially low production costs. Current designs for monolithic tandems rely ...

2017

The Role of Water in the Reversible Optoelectronic Degradation of Hybrid Perovskites at Low Pressure

Christophe Ballif, Michael Elias Stückelberger, Jérémie Werner, Björn Niesen

There is no doubt about the potential offered by the low-cost fabrication and high efficiency of hybrid organic inorganic perovskite solar cells. However, the service lifetimes of these devices must be increased from months to years to capitalize on their ...

American Chemical Society2017

Spectrally resolved nonlinearity and temperature dependence of perovskite solar cells

Christophe Ballif, Jérémie Werner, Florent Sahli, Björn Niesen, Matthias Wolfgang Bräuninger

An accurate electrical device characterization of hybrid organic-inorganic halide perovskite solar cells (PSCs) is an important prerequisite for further improvement and industrial transfer of this promising photovoltaic technology. In this work, we study t ...

Elsevier2017

Efficient Monolithic Perovskite/Perovskite Tandem Solar Cells

Christophe Ballif, Jérémie Werner, Björn Niesen

Efficient monolithic perovskite/perovskite tandem solar cells are fabricated using two perovskite absorbers with complementary bandgaps. By employing doped organic semiconductors, an efficient and selective extraction of the charge carriers is ensured. Thi ...

Wiley-VCH Verlag Berlin2017

Photocurrent Spectroscopy of Perovskite Layers and Solar Cells: A Sensitive Probe of Material Degradation

Christophe Ballif, Stefaan De Wolf, Jérémie Werner, Jakub Holovsky, Björn Niesen, Martin Ledinsky, Philipp Friedrich Hermann Löper, Martin Müller

Optical absorptance spectroscopy of polycrystalline CH3NH3PbI3 films usually indicates the presence of a PbI2 phase, either as a preparation residue or due to film degradation, but gives no insight on how this may affect electrical properties. Here, we app ...

Amer Chemical Soc2017

Imaging the Spatial Evolution of Degradation in Perovskite/Si Tandem Solar Cells After Exposure to Humid Air

Christophe Ballif, Stefaan De Wolf, Jérémie Werner, Florent Sahli, Björn Niesen, Randall Ellingson

Monolithically integrated two-terminal perovskite/Si tandem solar cells promise to achieve high power conversion efficiency. However, there is a concern that the stability of the perovskite top cell will limit the long-term performance of tandem devices. T ...

Ieee-Inst Electrical Electronics Engineers Inc2017

Perovskite/silicon tandem solar cells: marriage of convenience or true love story? - An overview

Christophe Ballif, Jérémie Werner, Björn Niesen

Perovskite/silicon tandem solar cells have reached efﬁciencies above 25% in just about three years of development, mostly driven by the rapid progress made in the perovskite solar cell research ﬁeld. This review aims to give an overview of the achievements ...

2017