Publications de Jonas Geissbühler

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

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

2021

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

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

Christophe Ballif, Antoine Descoeudres, Nicolas Badel, 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

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

Strategies for Doped Nanocrystalline Silicon Integration in Silicon Heterojunction Solar Cells

Christophe Ballif, Aïcha Hessler-Wyser, Antoine Descoeudres, Niels Holm, Martial Duchamp, Stefaan De Wolf, Jonas Geissbühler, Johannes Peter Seif, Simon Hänni, Gizem Nogay, Martin Ledinsky

Carrier collection in silicon heterojunction (SHJ) solar cells is usually achieved by doped amorphous silicon layers of a few nanometers, deposited at opposite sides of the crystalline silicon wafer. These layers are often defect-rich, resulting in modest ...

Ieee-Inst Electrical Electronics Engineers Inc2016

Efficient silicon solar cells with dopant-free asymmetric heterocontacts

Christophe Ballif, Stefaan De Wolf, Jonas Geissbühler

A salient characteristic of solar cells is their ability to subject photo-generated electrons and holes to pathways of asymmetrical conductivity-'assisting' them towards their respective contacts. All commercially available crystalline silicon (c-Si) solar ...

Nature Publishing Group2016

Profilometry of thin films on rough substrates by Raman spectroscopy

Christophe Ballif, Stefaan De Wolf, Matthieu Despeisse, Jonas Geissbühler, Andrea Tomasi, Bertrand Yves Paul Paviet-Salomon, Martin Ledinsky

Thin, light-absorbing films attenuate the Raman signal of underlying substrates. In this article, we exploit this phenomenon to develop a contactless thickness profiling method for thin films deposited on rough substrates. We demonstrate this technique by ...

Nature Research2016

Advanced Architectures and Processing for High-Efficiency Silicon Heterojunction Solar Cells

Jonas Geissbühler

Crystalline silicon solar cells currently represent the largest part of the photovoltaic market. In response to the demand for higher efficiency devices, silicon heterojunction technology, which merges a crystalline silicon wafer with thin amorphous silico ...

EPFL2015

Silicon Heterojunction Solar Cells With Copper-Plated Grid Electrodes: Status and Comparison With Silver Thick-Film Techniques

Christophe Ballif, Antoine Descoeudres, Nicolas Badel, Antonin Faes, Quentin Thomas Jeangros, Stefaan De Wolf, Matthieu Despeisse, Loris Barraud, Jonas Geissbühler, Andrea Tomasi

Copper electroplating is investigated and compared with common silver printing techniques for the front metallization of silicon heterojunction solar cells. We achieve smaller feature sizes by electroplating, significantly reducing optical shadowing losses ...

Ieee-Inst Electrical Electronics Engineers Inc2014

Fabrication and characterization of monolithically integrated microchannel plates based on amorphous silicon

Christophe Ballif, Nicolas Würsch, Jonas Geissbühler, Andrea Franco

Microchannel plates are vacuum-based electron multipliers for particle—in particular, photon— detection, with applications ranging from image intensifiers to single-photon detectors. Their key strengths are large signal amplification, large active area, mi ...

Nature Publishing Group2014

Back-Contacted Silicon Heterojunction Solar Cells With Efficiency >21%

Christophe Ballif, Antoine Descoeudres, Stefaan De Wolf, Jonas Geissbühler, Andrea Tomasi, Bertrand Yves Paul Paviet-Salomon, Silvia Martin de Nicolas Agut

We report on the fabrication of back-contacted silicon heterojunction solar cells with conversion efficiencies above 21%. Our process technology relies solely on simple and size-scalable patterning methods, with no high-temperature steps. Using in situ sha ...

Ieee-Inst Electrical Electronics Engineers Inc2014

Amorphous/crystalline silicon interface defects induced by hydrogen plasma treatments

Christophe Ballif, Bénédicte Demaurex, Duncan Thomas Lindsay Alexander, Stefaan De Wolf, Loris Barraud, Jonas Geissbühler, Johannes Peter Seif

Excellent amorphous/crystalline silicon interface passivation is of extreme importance for high-efficiency silicon heterojunction solar cells. This can be obtained by inserting hydrogen-plasma treatments during deposition of the amorphous silicon passivati ...

American Institute of Physics2013