Publications de Johannes Peter Seif

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

The impact of silicon solar cell architecture and cell interconnection on energy yield in hot & sunny climates

Christophe Ballif, Jacques Levrat, Stefaan De Wolf, Matthieu Despeisse, Jean Cattin, Yannick Samuel Riesen, Johannes Peter Seif, Andrea Tomasi, Jan Haschke, Brahim Aissa

Extensive knowledge of the dependence of solar cell and module performance on temperature and irradiance is essential for their optimal application in the field. Here we study such dependencies in the most common high-efficiency silicon solar cell architec ...

Royal Soc Chemistry2017

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

Impact of organic overlayers on a-Si:H/c-Si surface potential

Christophe Ballif, Stefaan De Wolf, Johannes Peter Seif, Andrea Tomasi, Björn Niesen

Bilayers of intrinsic and doped hydrogenated amorphous silicon, deposited on crystalline silicon (c-Si) surfaces, simultaneously provide contact passivation and carrier collection in silicon heterojunction solar cells. Recently, we have shown that the pres ...

American Institute of Physics2017

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

Characterizing amorphous silicon, silicon nitride, and diffused layers in crystalline silicon solar cells using micro-photoluminescence spectroscopy

Stefaan De Wolf, Johannes Peter Seif

We report and explain the photoluminescence (PL) spectra from crystalline silicon (c-Si) wafers passivated by hydrogenated amorphous silicon (a-Si:H) films under various measurement conditions, utilizing the different absorption coefficients and radiative ...

Elsevier Science Bv2016

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 Monolithic Perovskite/Silicon Tandem Solar Cell with Cell Area >1 cm

Christophe Ballif, Arnaud Walter, Stefaan De Wolf, Luc Fesquet, Jérémie Werner, Johannes Peter Seif, Björn Niesen, Ching-Hsun Weng

Monolithic perovskite/crystalline silicon tandem solar cells hold great promise for further performance improvement of well-established silicon photovoltaics; however, monolithic tandem integration is challenging, evidenced by the modest performances and s ...

Amer Chemical Soc2016

Transparent Electrodes in Silicon Heterojunction Solar Cells: Influence on Contact Passivation

Christophe Ballif, Sylvain Nicolay, Stefaan De Wolf, Florent Sahli, Loris Barraud, Johannes Peter Seif, Lorenzo Fanni, Andrea Tomasi, Bertrand Yves Paul Paviet-Salomon, Björn Niesen, Silvia Martin de Nicolas Agut

Charge carrier collection in silicon heterojunction solar cells occurs via intrinsic/doped hydrogenated amorphous silicon layer stacks deposited on the crystalline silicon wafer surfaces. Usually, both the electron and hole collecting stacks are externally ...

Ieee-Inst Electrical Electronics Engineers Inc2016

Nanocrystalline Silicon Carrier Collectors for Silicon Heterojunction Solar Cells and Impact on Low-Temperature Device Characteristics

Christophe Ballif, Quentin Thomas Jeangros, Stefaan De Wolf, Nicolas Würsch, Franz-Josef Haug, Yannick Samuel Riesen, Johannes Peter Seif, Andrea Tomasi, Gizem Nogay

Silicon heterojunction solar cells typically use stacks of hydrogenated intrinsic/doped amorphous silicon layers as carrier selective contacts. However, the use of these layers may cause parasitic optical absorption losses and moderate fill factor (FF) val ...

Ieee-Inst Electrical Electronics Engineers Inc2016

Asymmetric band offsets in silicon heterojunction solar cells: Impact on device performance

Christophe Ballif, Antoine Descoeudres, Stefaan De Wolf, Loris Barraud, Johannes Peter Seif, Ugur Deneb Menda

Amorphous/crystalline silicon interfaces feature considerably larger valence than conduction band offsets. In this article, we analyze the impact of such band offset asymmetry on the performance of silicon heterojunction solar cells. To this end, we use si ...

Amer Inst Physics2016

Amorphous/Crystalline Silicon Interface Passivation: Ambient-Temperature Dependence and Implications for Solar Cell Performance

Christophe Ballif, Bénédicte Demaurex, Stefaan De Wolf, Johannes Peter Seif

Silicon heterojunction (SHJ) solar cells feature amorphous silicon passivation films, which enable very high voltages. We report how such passivation increases with operating temperature for amorphous silicon stacks involving doped layers and decreases for ...

Ieee-Inst Electrical Electronics Engineers Inc2015

Window Layers for Silicon Heterojunction Solar Cells : Properties and Impact on Device Performance

Johannes Peter Seif

Currently, crystalline silicon (c-Si) wafer-based solar cells dominate the photovoltaic market (80-90%). In this thesis we concentrate on silicon heterojunction (SHJ) solar cells that--in contrast to diffused homojunction cells--rely on the application of ...

EPFL2015

Low-temperature plasma-deposited silicon epitaxial films: Growth and properties

Christophe Ballif, Bénédicte Demaurex, Quentin Thomas Jeangros, Duncan Thomas Lindsay Alexander, Stefaan De Wolf, Johannes Peter Seif

Low-temperature (

American Institute of Physics2014

Amorphous silicon oxide window layers for high-efficiency silicon heterojunction solar cells

Christophe Ballif, Antoine Descoeudres, Stefaan De Wolf, Johannes Peter Seif

In amorphous/crystalline silicon heterojunction solar cells, optical losses can be mitigated by replacing the amorphous silicon films by wider bandgap amorphous silicon oxide layers. In this article, we use stacks of intrinsic amorphous silicon and amorpho ...

American Institute of Physics2014

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

Improved amorphous/crystalline silicon interface passivation by hydrogen plasma treatment

Christophe Ballif, Antoine Descoeudres, Benjamin Strahm, Bénédicte Demaurex, Stefaan De Wolf, Loris Barraud, Jakub Holovsky, Johannes Peter Seif

Silicon heterojunction solar cells have high open-circuit voltages thanks to excellent passivation of the wafer surfaces by thin intrinsic amorphous silicon (a-Si:H) layers deposited by plasma-enhanced chemical vapor deposition. We show a dramatic improvem ...

2011