Publications de Andrea Tomasi | EPFL Graph Search

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

Christophe Ballif, Quentin Thomas Jeangros, Antoine Descoeudres, Antonin Faes, Gabriel Christmann, Jonas Geissbühler, Matthieu Despeisse, Bertrand Yves Paul Paviet-Salomon, Stefaan De Wolf, Nicolas Badel

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

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

Christophe Ballif, Florent Sahli, Aïcha Hessler-Wyser, Matthias Wolfgang Bräuninger, Quentin Thomas Jeangros, Bertrand Yves Paul Paviet-Salomon, Matthieu Despeisse, Stefaan De Wolf, Sylvain Nicolay, Björn Niesen

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

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

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

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

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

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

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

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

Profilometry of thin films on rough substrates by Raman spectroscopy

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

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

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

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

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

Back-Contacted Silicon Heterojunction Solar Cells

Andrea Tomasi

Wood/timber has been widely used for house and bridge construction. It is a widely available natural material that necessitates low energy for the production, following simple processes. The environmentally friendliness, together with the low cost of raw m ...

EPFL2016

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

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

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

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

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

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