Publications by Christian Michael Wolff

Beyond Flat: Undulated Perovskite Solar Cells on Microscale Si Pyramids by Solution Processing

Christophe Ballif, Aïcha Hessler-Wyser, Mostafa Rabie Shlaly Bahr Othman, Kerem Artuk, Deniz Türkay, Christian Michael Wolff

Microscale pyramids of silicon solar cells are often considered incompatible with solution-processed perovskite films. Thus, solution processing has mainly been used with submicron pyramids that are buried under thick perovskite films with flattened front ...

AMER CHEMICAL SOC2025

Template-Assisted Growth of CsxFA1-xPbI3 with Pulsed Laser Deposition for Single Junction Perovskite Solar Cells

Kerem Artuk, Christian Michael Wolff

Cesium-formamidinium lead iodide (CsxFA1-xPbI3) perovskites are a promising methylammonium-free alternative for efficient single-junction solar cells. However, they have not been fully explored by vapor-phase deposition techniques. Herein, a template-assis ...

2025

Monolithic Two-Terminal Perovskite/Perovskite/Silicon Triple-Junction Solar Cell with Open Circuit Voltage > 3.0 V

Kerem Artuk, Christian Michael Wolff

FUNDACIO DE LA COMUNITAT VALENCIANA SCITO2025

Aryl-Acetylene Layered Hybrid Perovskites in Photovoltaics

Christophe Ballif, Aïcha Hessler-Wyser, Michael Graetzel, Ursula Röthlisberger, Mostafa Rabie Shlaly Bahr Othman, Masaud Hassan S Almalki, Fatemeh Ansari, Felix Thomas Eickemeyer, Lukas Pfeifer, Christian Michael Wolff, Nikolaos Lempesis, Virginia Carnevali

Metal halide perovskites have shown exceptional potential in converting solar energy to electric power in photovoltaics, yet their application is hampered by limited operational stability. This stimulated the development of hybrid layered (two-dimensional, ...

WILEY-V C H VERLAG GMBH2025

Accelerating Optimization of Halide Perovskites: Two Blueprints for Automation

Christophe Ballif, Daniel Anthony Jacobs, Christian Michael Wolff

The fine-tuning of halide perovskite materials for both performance and stability calls for innovative tools that streamline high-throughput experimentation. Here, we present two complementary systems designed to accelerate the development of solution-proc ...

2025

Enhancing lifetime, forecasting, and economic benefits of photovoltaic technologies undergoing UV-induced degradation with optical filtering

Christophe Ballif, Antonin Faes, Marion Solange Madeleine Dussouillez, Christian Michael Wolff

Ultraviolet-induced degradation (UV-ID) of various PV cell types was analyzed under optical UV filters with different cutoff wavelengths. Cell types studied included interdigitated back contact (IBC), passivated emitter and rear totally diffused (PERT), an ...

2025

Making from Breaking: Degradation Inversion Enables Vapor-Phase Synthesis of Halide Perovskites in Ambient Conditions

Christophe Ballif, Aïcha Hessler-Wyser, Mostafa Rabie Shlaly Bahr Othman, Kerem Artuk, Christian Michael Wolff, Austin George Kuba

Vapor phase deposition of formamidinium-rich perovskites is hampered by the decomposition of formamidine in the vapor phase. We use the reversibility of this reaction to establish a dynamic equilibrium that enables the vapor-phase synthesis of formamidiniu ...

American Chemical Society (ACS)2025

Point contacts in halide perovskite solar cells: from reduced interfacial recombination to increased ionic field screening

Christian Michael Wolff

Inserting point contacts between the perovskite and C60 layers reduces the interfacial recombination. However, the accumulation of mobile ions at the point contacts can decrease the device stability. ...

Royal Society of Chemistry (RSC)2025

Self-Aligned Silica Nanoparticle Rear Reflectors for Single-Junction Si and Perovskite-Si Tandem Solar Cells

Christophe Ballif, Kerem Artuk, Deniz Türkay, Christian Michael Wolff

Infrared light management is crucial to maximize the optical performance of crystalline Si-based single junction and tandem solar cells. For this end, a low refractive index dielectric is typically inserted under the rear metal and an electrical contact is ...

2025

Towards stable perovskite multijunction solar cells: from nanometer- to wafer-scale

Christian Michael Wolff

FUNDACIO DE LA COMUNITAT VALENCIANA SCITO2025

Suppression of Stacking Faults for Stable Formamidinium-Rich Perovskite Absorbers

Christophe Ballif, Aïcha Hessler-Wyser, Ursula Röthlisberger, Mostafa Rabie Shlaly Bahr Othman, Kerem Artuk, Victor Carle Adrien Boureau, Christian Michael Wolff, Nikolaos Lempesis, Virginia Carnevali, Lorenzo Agosta, Austin George Kuba

The poor intrinsic perovskite absorber stability is arguably a central limitation challenging the prospect of commercialization for photovoltaic (PV) applications. Understanding the nanoscopic structural features that trigger instabilities in perovskite ma ...

WILEY-V C H VERLAG GMBH2025

Hybrid Sequential Process for Perovskite Absorbers Growth by Pulsed Laser Deposition (PLD)

Kerem Artuk, Christian Michael Wolff

FUNDACIO DE LA COMUNITAT VALENCIANA SCITO2025

Advancing high-throughput combinatorial aging studies of hybrid perovskite thin films via precise automated characterization methods and machine learning assisted analysis

Christian Michael Wolff, Alexander Wieczorek, Austin George Kuba

To optimize material stability, automated high-throughput workflows are of increasing interest. However, many of those workflows either employ synthesis techniques not suitable for large-area depositions or are carried out in ambient conditions, which limi ...

Royal Society of Chemistry2024

Assessing the Influence of Illumination on Ion Conductivity in Perovskite Solar Cells

Christophe Ballif, Aïcha Hessler-Wyser, Mostafa Rabie Shlaly Bahr Othman, Christian Michael Wolff

Whether illumination influences the ion conductivity in lead-halide perovskite solar cells containing iodide halides has been an ongoing debate. Experiments to elucidate the presence of a photoconductive effect require special devices or measurement techni ...

2024

Bifacial perovskite/silicon heterojunction tandem solar cells based on FAPbI3-based perovskite via hybrid evaporation-spin coating

Christophe Ballif, Aïcha Hessler-Wyser, Mounir Driss Mensi, Mostafa Rabie Shlaly Bahr Othman, Kerem Artuk, Deniz Türkay, Christian Michael Wolff

Combining the two technologies of tandem solar cells and bifacial solar cells has a great potential to maximize energy harvesting while minimizing material and surface usage. Mid-bandgap perovskites (1.50–1.60 eV) are important for fulfilling current match ...

Elsevier2024

Towards stable perovskite-silicon tandem solar cells: from nanometer- to wafer-scale

Christian Michael Wolff

FUNDACIO DE LA COMUNITAT VALENCIANA SCITO2024

Pizza Oven Processing of Organohalide Perovskites (POPOP): A Simple, Versatile and Efficient Vapor Deposition Method

Christophe Ballif, Cédric Bucher, Quentin Jean-Marie Armand Guesnay, Kerem Artuk, Deniz Türkay, Christian Michael Wolff, Austin George Kuba

Hybrid vapor deposition is one of the most appealing processes for perovskite photovoltaics fabrication, thanks to its versatile nature. By using sequentially different vapor deposition processes tailored to the inorganic and organic perovskite precursors' ...

Wiley-V C H Verlag Gmbh2024

In Situ Buried Interface Engineering towards Printable Pb−Sn Perovskite Solar Cells

Fan Fu, Christian Michael Wolff

High-efficiency Pb−Sn narrow-bandgap perovskite solar cells (PSCs) heavily rely on PEDOT:PSS as the hole-transport layer (HTL) owing to its excellent electrical conductivity, dopant-free nature, and facile solution processability. However, the shallow work ...

American Chemical Society (ACS)2024

Improving the operational stability of perovskite solar cells with cesium-doped graphene oxide interlayer

Michael Graetzel, Shaik Mohammed Zakeeruddin, Rita Therisod, Mostafa Rabie Shlaly Bahr Othman, Masaud Hassan S Almalki, Felix Thomas Eickemeyer, Hong Zhang, Lukas Pfeifer, Christian Michael Wolff

Perovskite solar cells (PSCs) have made great advances in terms of power conversion efficiency (PCE), yet their subpar stability continues to hinder their commercialization. The interface between the perovskite layer and the charge-carrier transporting lay ...

Elsevier2024

Synergetic substrate and additive engineering for over 30%-efficient perovskite-Si tandem solar cells

Christophe Ballif, Mounir Driss Mensi, Quentin Thomas Jeangros, Mathieu Gérard Boccard, Daniel Anthony Jacobs, Kerem Artuk, Xin Yu Chin, Deniz Türkay, Christian Michael Wolff

Perovskite-silicon (Si) tandem solar cells are the most prominent contenders to succeed single-junction Si cells that dominate the market today. Yet, to justify the added cost of inserting a perovskite cell on top of Si, these devices should first exhibit ...

2024