Publications by Grégory Bugnon

Comparison of LPCVD and sputter-etched ZnO layers applied as front electrodes in tandem thin-film silicon solar cells

Christophe Ballif, Franz-Josef Haug, Grégory Bugnon, Michael Elias Stückelberger, Etienne Antoine Julien Moulin

Aluminum-doped zinc oxide (ZnO:Al) layers deposited by sputtering and boron-doped zinc oxide (ZnO:B) layers deposited by low-pressure chemical vapor deposition (LPCVD) are well-established materials for front electrodes in thin-film silicon solar cells. In ...

Elsevier2016

Amorphous silicon-germanium for triple and quadruple junction thin-film silicon based solar cells

Christophe Ballif, Franz-Josef Haug, Matthieu Despeisse, Mathieu Gérard Boccard, Grégory Bugnon, Björn Niesen, Michael Elias Stückelberger, Maximilien Joseph Marie Bonnet-Eymard

We study amorphous silicon-germanium (a-SiGe:H) as intrinsic absorber material for thin-film silicon-based triple and quadruple junction solar cells. First, we present the development of a-SiGe:H single junction devices, in particular the Ge-content gradin ...

Elsevier2015

The boron-tailing myth in hydrogenated amorphous silicon solar cells

Christophe Ballif, Franz-Josef Haug, Matthieu Despeisse, Grégory Bugnon, Michael Elias Stückelberger

The boron-tailing effect in hydrogenated amorphous silicon (a-Si:H) solar cells describes the reduced charge collection specifically in the blue part of the spectrum for absorber layers deposited above a critical temperature. This effect limits the device ...

AIP American Institute of Physics2015

Silicon oxide buffer layer at the p-i interface in amorphous and microcrystalline silicon solar cells

Christophe Ballif, Matthieu Despeisse, Gaetano Parascandolo, Grégory Bugnon, Michael Elias Stückelberger, Mathieu Charrière

The use of intrinsic silicon oxide as a buffer layer at the p-i interface of thin-film silicon solar cells is shown to provide significant advantages. For microcrystalline silicon solar cells, when associated with highly crystalline i-layers deposited at h ...

Elsevier2014

Thin-Film Silicon Triple-Junction Solar Cells on Highly Transparent Front Electrodes With Stabilized Efficiencies up to 12.8%

Christophe Ballif, Franz-Josef Haug, Matthieu Despeisse, Mathieu Gérard Boccard, Grégory Bugnon, Michael Elias Stückelberger

High-efficiency thin-film silicon triple-junction solar cells in p-i-n configuration have been fabricated using amorphous silicon top cell absorber layers, as well as microcrystalline silicon middle and bottom cell absorbers. The triple-junction cells were ...

Ieee-Inst Electrical Electronics Engineers Inc2014

High-Stable-Efficiency Tandem Thin-Film Silicon Solar Cell With Low-Refractive-Index Silicon-Oxide Interlayer

Christophe Ballif, Xavier Niquille, Matthieu Despeisse, Mathieu Gérard Boccard, Jordi Escarre Palou, Grégory Bugnon, Maximilien Joseph Marie Bonnet-Eymard

We report the recent advances and key requirements for high-efficiency "micromorph" tandem thin-film silicon solar cells composed of an amorphous silicon top cell and a microcrystalline silicon bottom cell. The impact of inserting a low-refractive-index si ...

Ieee-Inst Electrical Electronics Engineers Inc2014

Post-deposition treatment of microcrystalline silicon solar cells for improved performance on rough superstrates

Christophe Ballif, Mathieu Gérard Boccard, Sylvain Nicolay, Laura Ding, Grégory Bugnon

In this contribution, we investigate the effect of post-deposition treatments on finished non-encapsulated thin-film microcrystalline silicon solar cells and show that annealing in vacuum leads to improved electrical properties of the solar cells, particul ...

American Institute of Physics2014

Light trapping in thin-film solar cells measured by Raman spectroscopy

Christophe Ballif, Grégory Bugnon, Etienne Antoine Julien Moulin, Martin Ledinsky

In this study, Raman spectroscopy is used as a tool to determine the light-trapping capability of textured ZnO front electrodes implemented in microcrystalline silicon (mu c-Si:H) solar cells. Microcrystalline silicon films deposited on superstrates of var ...

American Institute of Physics2014

Ethanol-enriched low-pressure chemical vapor deposition ZnO bilayers: Properties and growth-A potential electrode for thin film solar cells

Christophe Ballif, Sylvain Nicolay, Laura Ding, Grégory Bugnon

Ethanol is used as a precursor during the growth of zinc oxide (ZnO) by low-pressure chemical vapor deposition (LPCVD). By adding ethanol, the surface of the deposited ZnO layer is flattened and its roughness is decreased about sevenfold. The layers become ...

American Institute of Physics2013

Optimized short-circuit current mismatch in multi-junction solar cells

Christophe Ballif, Matthieu Despeisse, Mathieu Gérard Boccard, Grégory Bugnon, Fanny Sculati-Meillaud, Maximilien Joseph Marie Bonnet-Eymard

Multi-junction photovoltaic devices include two or more component sub-cells which are electrically interconnected in series. At any power point, the current output of the total device is limited by the sub-cell with the smallest current density. Therefore, ...

Elsevier2013