Publications by Julie Amandine Dreon

Loss Analysis of a 24.4%-Efficient Front-Junction Silicon Heterojunction Solar Cell and Opportunity for Localized Contacts

Christophe Ballif, Mathieu Gérard Boccard, Jean Cattin, Luca Massimiliano Antognini, Vincent Philippe Paratte, Julie Amandine Dreon, Deniz Türkay

Silicon heterojunction (SHJ) solar cells have recently reached power conversion efficiencies above 25% with various device architectures and with industrial size (>200 cm(2)) wafers. Yet, for an accurate assessment of the efficiency potential and further d ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2023

Carrier-selective contacts using metal compounds for crystalline silicon solar cells

Mathieu Gérard Boccard, Julie Amandine Dreon

Solar cells rely on the efficient generation of electrons and holes and the subsequent collection of these photoexcited charge carriers at spatially separated electrodes. High wafer quality is now commonplace for crystalline silicon (c-Si) based solar cell ...

WILEY2023

Molybdenum oxide as a case study for the diagnosis of carrier selective contacts in silicon heterojunction solar cells

Julie Amandine Dreon

Environmental challenges impose a rapid energy transition. The renewable power capacity is expected to increase by 50% in the next 5 years, and recent scenarios plan that photovoltaics (PV) will be leading the new energy sources. Combining high efficiencie ...

EPFL2022

Integration of thin n-type nc-Si:H layers in the window-multilayer stack of heterojunction solar cells

Christophe Ballif, Mathieu Gérard Boccard, Luca Massimiliano Antognini, Vincent Philippe Paratte, Laurie-Lou Senaud, Julie Amandine Dreon, Corentin Yann Sthioul

N-type nanocrystalline silicon (nc-Si:H(n)) layers are good candidates to improve current and transport properties in heterojunction solar cells. In this work, we perform thickness series alongside PH3 doping series to unravel the desirable characteristics ...

ELSEVIER2022

Contact Resistivity Measurements and their Applicability for Accurate Series Resistance Breakdown in Heterojunction Solar Cell

Christophe Ballif, Mathieu Gérard Boccard, Matthieu Despeisse, Luca Massimiliano Antognini, Laurie-Lou Senaud, Bertrand Yves Paul Paviet-Salomon, Lison Sylou Marthey, Julie Amandine Dreon, Deniz Türkay

In this work, we use several approaches to perform accurate Series Resistance (R-S) breakdown of a state of the art 2 cm x 2 cm screen-printed solar cell reaching 82.5% FF. On the one hand, Haschke et al.'s model for the lateral transport through the cell, ...

AMER INST PHYSICS2022

Influence of the Dopant Gas Precursor in P-Type Nanocrystalline Silicon Layers on the Performance of Front Junction Heterojunction Solar Cells

Christophe Ballif, Quentin Thomas Jeangros, Mathieu Gérard Boccard, Jean Cattin, Luca Massimiliano Antognini, Mario Joe Lehmann, Vincent Philippe Paratte, Laurie-Lou Senaud, Jan Haschke, Julie Amandine Dreon

Silicon heterojunction solar cells can employ p-type hydrogenated nanocrystalline silicon nc-Si:H(p) on their front side, since these can provide better transparency and contact resistance compared to hydrogenated p-type amorphous silicon layers. We invest ...

2021

ZnSnxGe1-xN2 as electron-selective contact for silicon heterojunction solar cells

Christophe Ballif, Mathieu Gérard Boccard, Jonathan Emanuel Thomet, Luca Massimiliano Antognini, Vincent Philippe Paratte, Julie Amandine Dreon, Julien Hurni, Davi Marcelo Fébba

This work reports the electrical characterization of ZnSnxGe1-xN2 (ZTGN) layers deposited on glass by sputtering and further assesses for the first time the performance of SHJ solar cells featuring them as electron-selective contacts. Bandgap, conductivity ...

IEEE2021

Temperature‐dependent performance of silicon heterojunction solar cells with transition‐metal‐oxide‐based selective contacts

Mathieu Gérard Boccard, Julie Amandine Dreon

The temperature coefficient (TC) is an essential figure of merit to accurately evaluate solar cell performance at various operating temperatures and hence enabling the comparison between different cell technologies. Recently, solar cells that use passivati ...

2021

Dopant-Free Bifacial Silicon Solar Cells

Christophe Ballif, Mathieu Gérard Boccard, Jean Cattin, Luca Massimiliano Antognini, Vincent Philippe Paratte, Julie Amandine Dreon, Sihua Zhong, Wenjie Lin, Hui Shen

Herein, challenges in the fabrication of full dopant-free bifacial silicon solar cells are discussed and efficient devices utilizing a MoO3/ indium tin oxide (ITO)/Ag hole-selective contact and ZnO/LiFx/Al electron-selective contacts with up to 79% short-c ...

2021

Effects of work function and electron affinity on the performance of carrier-selective contacts in silicon solar cells using $ZnSn_{x}Ge_{1-x}N_{2}$ as a case study

Christophe Ballif, Mathieu Gérard Boccard, Jonathan Emanuel Thomet, Luca Massimiliano Antognini, Vincent Philippe Paratte, Julie Amandine Dreon, Julien Hurni, Davi Marcelo Fébba

2021

Effects of Work Function and Electron Affinity on the Performance of Carrier-Selective Contacts in Silicon Solar Cells Using ZnSnx Ge-1 (-) N-x(2) as a Case Study

Christophe Ballif, Mathieu Gérard Boccard, Jonathan Emanuel Thomet, Luca Massimiliano Antognini, Vincent Philippe Paratte, Julie Amandine Dreon, Julien Hurni

This work reports the electrical characterization of ZnSnx Ge1 - xN2 (ZTGN) layers (10% < x < 90%) deposited on glass by combinatorial sputtering and further assesses the performance of silicon heterojunction (SHJ) solar cells featuring them as electron-se ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2021

Performance Limitations and Analysis of Silicon Heterojunction Solar Cells Using Ultra-Thin MoOx Hole-Selective Contacts

Christophe Ballif, Gabriel Christmann, Mathieu Gérard Boccard, Jean Cattin, Luca Massimiliano Antognini, Vincent Philippe Paratte, Julie Amandine Dreon

We recently showed that silicon heterojunction solar cell with MoOx-based hole-selective contact could reach 23.5% in efficiency with MoOx layers of 4 nm. Such thin MoOx layer enables a considerable current-density gain of over 1 mA/cm(2) compared to the u ...

2021

Hole-Selective Front Contact Stack Enabling 24.1%-Efficient Silicon Heterojunction Solar Cells

Christophe Ballif, Sylvain Nicolay, Mathieu Gérard Boccard, Matthieu Despeisse, Jean Cattin, Luca Massimiliano Antognini, Vincent Philippe Paratte, Laurie-Lou Senaud, Bertrand Yves Paul Paviet-Salomon, Minh Truong, Jan Haschke, Julie Amandine Dreon, Wenjie Lin

The window-layer stack limits the efficiency of both-side-contacted silicon heterojunction solar cells. We discuss here the combination of several modifications to this stack to improve its optoelectronic performance. These include the introduction of a na ...

2020

23.5%-efficient silicon heterojunction silicon solar cell using molybdenum oxide as hole-selective contact

Christophe Ballif, Quentin Thomas Jeangros, Mathieu Gérard Boccard, Jean Cattin, Luca Massimiliano Antognini, Jan Haschke, Julie Amandine Dreon

Elsevier2020

Degradation Mechanism and Stability Improvement of Dopant-Free ZnO/LiFx/Al Electron Nanocontacts in Silicon Heterojunction Solar Cells

Christophe Ballif, Quentin Thomas Jeangros, Mathieu Gérard Boccard, Jonathan Emanuel Thomet, Luca Massimiliano Antognini, Vincent Philippe Paratte, Julie Amandine Dreon, Sihua Zhong, Wenjie Lin

Dopant-free passivating contacts for photovoltaics have the potential to be deposited at low costs, while providing excellent surface passivation and low contact resistance. However, one pressing issue of dopant-free carrier selective contacts is their low ...

2020

Paths for maximal light incoupling and excellent electrical performances in silicon heterojunction solar cells

Christophe Ballif, Mathieu Gérard Boccard, Matthieu Despeisse, Jean Cattin, Raphaël Monnard, Luca Massimiliano Antognini, Vincent Philippe Paratte, Laurie-Lou Senaud, Monica Morales Masis, Bertrand Yves Paul Paviet-Salomon, Oscar Esteban Rucavado Leandro, Jan Haschke, Olivier Denis Dupré, Julie Amandine Dreon, Sihua Zhong, Angela Nicole Fioretti

We discuss here optical losses in silicon heterojunction solar cells and strategies to minimize them. Optical losses originate from most non-crystalline-silicon layers involved in the solar cell. A breakdown for typical values is shown evidencing that supp ...

IEEE2019

Mitigating Plasmonic Absorption Losses at Rear Electrodes in High‐Efficiency Silicon Solar Cells Using Dopant‐Free Contact Stacks

Christophe Ballif, Quentin Thomas Jeangros, Stefaan De Wolf, Mathieu Gérard Boccard, Julie Amandine Dreon, Sihua Zhong, Fan Fu

Although charge‐carrier selectivity in conventional crystalline silicon (c‐Si) solar cells is usually realized by doping Si, the presence of dopants imposes inherent performance limitations due to parasitic absorption and carrier recombination. The develop ...

2019

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