Publications by Peter Joseph Fiala

Interface passivation for 31.25%-efficient perovskite/silicon tandem solar cells

Christophe Ballif, Quentin Thomas Jeangros, Mounir Driss Mensi, Christian Michael Wolff, Daniel Anthony Jacobs, Deniz Türkay, Kerem Artuk, Mathieu Gérard Boccard, Peter Joseph Fiala, Quentin Jean-Marie Armand Guesnay

Silicon solar cells are approaching their theoretical efficiency limit of 29%. This limitation can be exceeded with advanced device architectures, where two or more solar cells are stacked to improve the harvesting of solar energy. In this work, we devise ...

American Association for the Advancement of Science2023

Correlating light-induced deep defects and phase segregation in mixed-halide perovskites

Quentin Thomas Jeangros, Jakub Holovsky, Christian Michael Wolff, Peter Joseph Fiala, Xin Yu Chin

Mixed-halide perovskites are highly promising materials for tandem solar cells. The phenomenon of phase segregation, however hinders their application. Here, we combine Fourier-Transform photocurrent spectroscopy with photoluminescence and current density- ...

Royal Society of Chemistry2022

Material Development for Perovskite/Silicon Tandem Photovoltaics

Peter Joseph Fiala

The developed world is built on the fact that energy is readily available and functionally infinite. The electricity from the wall, the gas at the station, and the heat in our homes are reliable and low-cost. But this comfort is so far only possible throug ...

EPFL2022

Nano-emitting Heterostructures Violate Optical Reciprocity and Enable Efficient Photoluminescence in Halide-Segregated Methylammonium-Free Wide Bandgap Perovskites

Christophe Ballif, Quentin Thomas Jeangros, Peter Joseph Fiala, Christian Michael Wolff, Chien-Jen Yang, Pietro Caprioglio

This work investigates halide segregation in methylammonium-free wide bandgap perovskites by photoluminescence quantum yield (PLQY) and advanced electron microscopy techniques. Our study reveals how the formation of nano-emitting low-energy domains embedde ...

AMER CHEMICAL SOC2021

Instability of p-i-n perovskite solar cells under reverse bias

Christophe Ballif, Quentin Thomas Jeangros, Florent Sahli, Arnaud Walter, Daniel Anthony Jacobs, Fan Fu, Ricardo Augusto Zanotto Razera, Sylvain Nicolay, Peter Joseph Fiala, Laura Ding

Partial shading can trigger permanent damage in photovoltaic modules because the illuminated solar cells drive the shaded cells into reverse bias. Under reverse bias conditions, perovskite solar cells have been shown to degrade quickly due to processes tha ...

Royal Society of Chemistry2020

I-2 vapor-induced degradation of formamidinium lead iodide based perovskite solar cells under heat-light soaking conditions

Christophe Ballif, Quentin Thomas Jeangros, Adriana Paracchino, Sylvain Nicolay, Jérémie Werner, Fan Fu, Peter Joseph Fiala, Léo Duchêne

Over the last years, the operational stability of perovskite solar cells has been significantly improved by compositional engineering, interface modification, and improved encapsulation techniques. However, irreversible degradation is still ubiquitously ob ...

2019

Complex Refractive Indices of Cesium–Formamidinium-Based Mixed-Halide Perovskites with Optical Band Gaps from 1.5 to 1.8 eV

Christophe Ballif, Jérémie Werner, Quentin Thomas Jeangros, Matthias Wolfgang Bräuninger, Gabriel Christmann, Florent Sahli, Arnaud Walter, Sylvain Nicolay, Björn Niesen, Gizem Nogay

Cesium-formamidinium-based mixed-halide perovskite materials with optical band gaps ranging from 1.5 to 1.8 eV are investigated by variable-angle spectroscopic ellipsometry. The determined complex refractive indices are shown to depend on the fabrication p ...

2018

High-Bandgap Perovskite Materials for Multijunction Solar Cells

Christophe Ballif, Quentin Thomas Jeangros, Chien-Jen Yang, Peter Joseph Fiala

2018

Hybrid sequential deposition process for fully textured perovskite/silicon tandem solar cells

Christophe Ballif, Quentin Thomas Jeangros, Davide Sacchetto, Bertrand Yves Paul Paviet-Salomon, Florent Sahli, Arnaud Walter, Gianluca Cattaneo, Matthieu Despeisse, Mathieu Gérard Boccard, Sylvain Nicolay

Tandem solar cells that feature a high-bandgap perovskite cell on top of a lower bandgap silicon cell have the potential to reach efficiencies > 30%. Here, we present a versatile hybrid deposition method that yields conformal perovskite cells directly on t ...

IEEE2018