Publications by Franz-Josef Haug

Co-annealing of PECVD boron emitters and poly-Si passivating contacts for leaner TOPCon solar cell fabrication

Christophe Ballif, Franz-Josef Haug, Sofia Libraro, Julien Hurni, Ezgi Genç

This study investigates the feasibility of a single-step annealing process for tunnel oxide passivating contact (TOPCon) solar cell fabrication to replace the conventional two-step approach. We present a novel method using a single thermal treatment to sim ...

2025

nc-SiC by PECVD for High-Temperature Passivating Contacts

Christophe Ballif, Franz-Josef Haug, Julien Hurni, Ezgi Genç

Institute of Electrical and Electronics Engineers (IEEE)2025

Boron-emitter development for TOPCon c-Si solar cells based on plasma-deposited boron diffusion source and poly-Si(n) passivating contact

Christophe Ballif, Franz-Josef Haug, Julien Hurni, Ezgi Genç

The n-type TOPCon technology is currently the leading approach in the industry. Generally, it involves two high-temperature steps that can result in long cycle times and expensive processes. In this context, we propose a lean manufacturing process based on ...

2025

Impact of Rapid Thermal Processing on Bulk Lifetime and Surface Recombination Velocity of Crystalline Silicon With Passivating Tunnel Oxide Contacts

Christophe Ballif, Franz-Josef Haug, Audrey Marie Isabelle Morisset, Sofia Libraro, Julien Hurni, Ezgi Genç

We investigate rapid thermal processing (RTP) as alternative to the prolonged thermal annealing process used to form tunnel-oxide passivating contacts for silicon solar cells. The thermal treatment is generally followed by hydrogenation to passivate defect ...

Wiley2025

Hole-Selective SiNx and AlOx Tunnel Nanolayers for Improved Polysilicon Passivating Contacts

Franz-Josef Haug, Audrey Marie Isabelle Morisset, Sofia Libraro, Ezgi Genç

A highly efficient hole-selective passivating contact remains the crucial step required to increase the efficiency of polysilicon-based Si solar cells. The future development of solar modules depends on a device structure that can complement the electron-s ...

2024

Development and characterization of N2O-plasma oxide layers for high-temperature p-type passivating contacts in silicon solar cells

Christophe Ballif, Franz-Josef Haug, Aïcha Hessler-Wyser, Audrey Marie Isabelle Morisset, Sofia Libraro, Julien Hurni, Ezgi Genç, David Fernando Reyes Vasquez

Full-area passivating contacts based on SiOx/poly-Si stacks are key for the new generation of industrial silicon solar cells substituting the passivated emitter and rear cell (PERC) technology. Demonstrating a potential efficiency increase of 1 to 2% compa ...

American Chemical Society (ACS)2024

Interactions between aluminium and fired passivating contacts during fire-through metallization (vol 249, 112051, 2023)

Christophe Ballif, Aïcha Hessler-Wyser, Franz-Josef Haug, Sofia Libraro, Antoine Descoeudres, Andrea Ingenito, Mario Joe Lehmann

Elsevier2024

Understanding and mitigating resistive losses in fired passivating contacts: role of the interfaces and optimization of the thermal budget

Christophe Ballif, Aïcha Hessler-Wyser, Franz-Josef Haug, Audrey Marie Isabelle Morisset, Sofia Libraro, Julien Hurni, Luca Massimiliano Antognini, Ezgi Genç

This work presents a study of p-type passivating contacts based on SiCx formed via a rapid thermal processing (RTP) step, using conditions compatible with the firing used to sinter screen-printed metallization pastes in industry. The contributions of the t ...

Elsevier2023

Passivating contact-based tunnel junction Si solar cells using machine learning for tandem cell applications

Christophe Ballif, Franz-Josef Haug, Aïcha Hessler-Wyser, Audrey Marie Isabelle Morisset, Hyunjung Park

Tandem solar cells are a key technology for exceeding the theoretical efficiency limit of single-junction cells. One of the most promising combinations is the silicon-perovskite tandem cells, considering their potential for high efficiency, fabrication on ...

ELSEVIER2023

Carrier generation and collection in Zn3P2/InP heterojunction solar cells

Anna Fontcuberta i Morral, Franz-Josef Haug, Valerio Piazza, Julien Hurni, Joel René Sapera, Mahdi Zamani, Simon Robert Escobar Steinvall, Rajrupa Paul, Mirjana Dimitrievska

Zinc phosphide (Zn3P2) has been lauded as a promising solar absorber material due to its functional properties and the abundance of zinc and phosphorous. In the last 4 decades, there has not been any significant improvement in the efficiencies of Zn3P2-bas ...

ELSEVIER2023