Publications de Olivier Ouellette

Cooperative passivation of perovskite solar cells by alkyldimethylammonium halide amphiphiles

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ursula Röthlisberger, Ulf Anders Hagfeldt, Thomas Paul Baumeler, David Lyndon Emsley, Essa Awadh R Alharbi, Mathias Dankl, Aditya Mishra, Felix Thomas Eickemeyer, Michael Allan Hope, Anurag Krishna, Olivier Ouellette, Lukas Pfeifer, Nikolaos Lempesis, Georgios Kakavelakis

2023

High-Work-Function 2D Perovskites as Passivation Agents in Perovskite Solar Cells

Michael Graetzel, Mohammad Khaja Nazeeruddin, Paul Joseph Dyson, Ulf Anders Hagfeldt, Antoine Philippe Van Muyden, Farzaneh Fadaei Tirani, Erfan Shirzadi, Hiroyuki Kanda, Brian Irving Carlsen, Fatemeh Ansari, Felix Thomas Eickemeyer, Olivier Ouellette, Hiroaki Jinno

Various approaches have been employed to passivate the defects in perovskite films used in perovskite solar cells (PSCs). However, the passivation mechanism is often unclear at a molecular level, and the reason for enhanced PSC performance often remains el ...

Amer Chemical Soc2023

Efficient and Stable Large Bandgap MAPbBr(3) Perovskite Solar Cell Attaining an Open Circuit Voltage of 1.65 V

Michael Graetzel, Shaik Mohammed Zakeeruddin, Thomas Paul Baumeler, David Lyndon Emsley, Linfeng Pan, Anwar Qasem M Alanazi, Yuhang Liu, Jing Gao, Felix Thomas Eickemeyer, Hongwei Zhu, Michael Allan Hope, Olivier Ouellette

We report on the preparation of MAPbBr(3) perovskite films of high electronic quality by applying a methylamine (MA) vapor treatment and mitigating surface defects using the amphiphilic molecular passivator, neopentylammonium chloride (NPACl). We find that ...

2022

Methylammonium Triiodide for Defect Engineering of High-Efficiency Perovskite Solar Cells

Michael Graetzel, Jacques-Edouard Moser, Shaik Mohammed Zakeeruddin, Mounir Driss Mensi, Ursula Röthlisberger, Ulf Anders Hagfeldt, Thomas Paul Baumeler, Linfeng Pan, Paramvir Ahlawat, Claudia Esther Avalos, Essa Awadh R Alharbi, Pascal Alexander Schouwink, George Cameron Fish, Mathias Dankl, Bowen Yang, Felix Thomas Eickemeyer, Viktor Skorjanc, Anurag Krishna, Olivier Ouellette, Elsa John, Lukas Pfeifer

The defects present in metal halide perovskite are deleterious to both the performance and stability of photovoltaic devices. Consequently, there is an intense focus on developing defect mitigation strategies. Herein we report a facile strategy that employ ...

2021

Multimodal host–guest complexation for efficient and stable perovskite photovoltaics

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ursula Röthlisberger, Ulf Anders Hagfeldt, Marko Mladenovic, David Lyndon Emsley, Farzaneh Jahanbakhshi, Paramvir Ahlawat, Zaiwei Wang, Jovana Milic, Dan Ren, Aditya Mishra, Felix Thomas Eickemeyer, Hong Zhang, Zhaowen Dong, Jinming Guo, Michael Allan Hope, Anurag Krishna, Olivier Ouellette, Tzu-Sen Su, Zhiwen Zhou

Formamidinium lead iodide perovskites are promising light-harvesting materials, yet stabilizing them under operating conditions without compromising optimal optoelectronic properties remains challenging. We report a multimodal host–guest complexation strat ...

Nature Research2021

Nanoscale interfacial engineering enables highly stable and efficient perovskite photovoltaics

Michael Graetzel, Shaik Mohammed Zakeeruddin, Mounir Driss Mensi, Ursula Röthlisberger, Ulf Anders Hagfeldt, Sandy Sanchez Alonso, Mathias Dankl, Hong Zhang, Anurag Krishna, Olivier Ouellette

We present a facile molecular-level interface engineering strategy to augment the long-term operational and thermal stability of perovskite solar cells (PSCs) by tailoring the interface between the perovskite and hole transporting layer (HTL) with a multif ...

2021

Formation of High-Performance Multi-Cation Halide Perovskites Photovoltaics by delta-CsPbI3/delta-RbPbI3 Seed-Assisted Heterogeneous Nucleation

Michael Graetzel, Shaik Mohammed Zakeeruddin, Mounir Driss Mensi, Ulf Anders Hagfeldt, Thomas Paul Baumeler, Linfeng Pan, Essa Awadh R Alharbi, Zaiwei Wang, Masaud Hassan S Almalki, Bowen Yang, Felix Thomas Eickemeyer, Anurag Krishna, Olivier Ouellette

The performance of perovskite solar cells is highly dependent on the fabrication method; thus, controlling the growth mechanism of perovskite crystals is a promising way towards increasing their efficiency and stability. Herein, a multi-cation halide compo ...

2021

Synergistic Effect of Fluorinated Passivator and Hole Transport Dopant Enables Stable Perovskite Solar Cells with an Efficiency Near 24%

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Linfeng Pan, Yuhang Liu, Felix Thomas Eickemeyer, Yameng Ren, Hongwei Zhu, Olivier Ouellette

Long-term durability is critically important for the commercialization of perovskite solar cells (PSCs). The ionic character of the perovskite and the hydrophilicity of commonly used additives for the hole-transporting layer (HTL), such as lithium bis(trif ...

2021

Combined Precursor Engineering and Grain Anchoring Leading to MA-Free, Phase-Pure, and Stable alpha-Formamidinium Lead Iodide Perovskites for Efficient Solar Cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Carole Graetzel, Linfeng Pan, Yuhang Liu, Dan Ren, Jing Gao, Hongwei Zhu, Anurag Krishna, Olivier Ouellette

alpha-Formamidinium lead iodide (alpha-FAPbI(3)) is one of the most promising candidate materials for high-efficiency and thermally stable perovskite solar cells (PSCs) owing to its outstanding optoelectrical properties and high thermal stability. However, ...

Wiley-VCH Verlag GmbH2021

Colloidal quantum dot photodetectors with 10-ns response time and 80% quantum efficiency at 1,550 nm

Olivier Ouellette

Fast and sensitive infrared (IR) photodetection is of interest for depth imaging that is fundamental to machine vision, augmented reality, and autonomous driving. Colloidal quantum dots (CQDs) are appealing candidates for this goal: in contrast with III-V ...

ELSEVIER2021

Crown Ether Modulation Enables over 23% Efficient Formamidinium-Based Perovskite Solar Cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Mounir Driss Mensi, Ursula Röthlisberger, Ulf Anders Hagfeldt, Jun Ho Yum, Kevin Sivula, Marko Mladenovic, David Lyndon Emsley, Farzaneh Jahanbakhshi, Jovana Milic, Dan Ren, Aditya Mishra, Felix Thomas Eickemeyer, Hong Zhang, Michael Allan Hope, Jun Li, Anurag Krishna, Olivier Ouellette, Zhiwen Zhou

The use of molecular modulators to reduce the defect density at the surface and grain boundaries of perovskite materials has been demonstrated to be an effective approach to enhance the photovoltaic performance and device stability of perovskite solar cell ...

2020