Publications de George Cameron Fish

Photo-doping of spiro-OMeTAD for highly stable and efficient perovskite solar cells

Michael Graetzel, Jacques-Edouard Moser, Kai Zhu, Etienne Christophe Socie, George Cameron Fish, Aaron Tomas Terpstra

A widely used component of high-efficiency perovskite solar cells (PSCs) is the molecular hole-transport material (HTM) spiro-OMeTAD. This organic solid needs to be p-doped to acquire sufficient hole conductivity. However, the conventional doping method us ...

2024

Surface Passivation of FAPbI3-Rich Perovskite with Cesium Iodide Outperforms Bulk Incorporation

Michael Graetzel, Shaik Mohammed Zakeeruddin, Jacques-Edouard Moser, Kevin Sivula, Jun Ho Yum, Mounir Driss Mensi, Felix Thomas Eickemeyer, Lukas Pfeifer, Jing Gao, Thomas Paul Baumeler

Metal halide perovskites (MHPs) have shown an incredible increase in efficiency, reaching as high as 25.7%, which now competes with traditional photovoltaic technologies. Herein, we excluded CsX and RbX (X = I–, Br–, Cl–), the most commonly used cations to ...

2023

Photogenerated charge transfer in Dion-Jacobson type layered perovskite based on naphthalene diimide

Jacques-Edouard Moser, Kevin Sivula, Jun Ho Yum, Etienne Christophe Socie, George Cameron Fish, Simon Nussbaum

Incorporating organic semiconducting spacer cations into layered lead halide perovskite structures provides a powerful approach to mitigate the typical strong dielectric and quantum confinement effects by inducing charge-transfer between the organic and in ...

2023

The Impact of Spacer Size on Charge Transfer Excitons in Dion–Jacobson and Ruddlesden–Popper Layered Hybrid Perovskites

Michael Graetzel, Jacques-Edouard Moser, Jovana Milic, Lukas Pfeifer, George Cameron Fish, Masaud Hassan S Almalki, Algirdas Ducinskas, Aaron Tomas Terpstra, Loï Charles Carbone

Organic materials can tune the optical properties in layered (2D) hybrid perovskites, although their impact on photophysics is often overlooked. Here, we use transient absorption spectroscopy to probe the Dion−Jacobson (DJ) and Ruddlesden−Popper (RP) 2D pe ...

2023

Dataset of "The Impact of Spacer Size on Charge Transfer Excitons in Dion-Jacobson and Ruddlesden-Popper Layered Hybrid Perovskites"

Michael Graetzel, Jacques-Edouard Moser, Lukas Pfeifer, George Cameron Fish, Aaron Tomas Terpstra, Masaud Hassan S Almalki

This dataset underpins the following article published in the Journal of Physical Chemistry Letters: "The Impact of Spacer Size on Charge Transfer Excitons in Dion-Jacobson and Ruddlesden-Popper Layered Hybrid Perovskites" DOI: 10.1021/acs.jpclett.3c01125 ...

Zenodo2023

Spatio-Temporal Dynamics of Free and Bound Carriers in Photovoltaic Materials

Jacques-Edouard Moser, George Cameron Fish

Photoinduced charge separation into free carriers and subsequent charge transfer are key processes that govern the efficiencies of third generation solar cell technologies based on donor-acceptor heterojunctions. As these processes typically occur on picos ...

2022

Unravelling the mechanism of ultrafast photoinduced charge generation in organic and hybrid photovoltaic systems

George Cameron Fish

At the current time, the world as we know it is at a crossroads; there is an urgent need to lower greenhouse gas emissions to limit the global rise in temperature. However, this is at odds with the increasing energy demands of the world's growing populatio ...

EPFL2022

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

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ursula Röthlisberger, Jacques-Edouard Moser, Mounir Driss Mensi, Pascal Alexander Schouwink, Felix Thomas Eickemeyer, Mathias Dankl, Ulf Anders Hagfeldt, 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

The Role of Alkyl Chain Length and Halide Counter Ion in Layered Dion−Jacobson Perovskites with Aromatic Spacers

Michael Graetzel, Jacques-Edouard Moser, Joachim Maier, Jovana Milic, Michael Allan Hope, George Cameron Fish, Algirdas Ducinskas, Loï Charles Carbone, Davide Moia

Layered hybrid perovskites based on Dion−Jacobson phases are of interest to various optoelectronic applications. However, the understanding of their structure−property relationships remains limited. Here, we present a systematic study of Dion−Jacobson pero ...

2021

Critical role of H-aggregation for high-efficiency photoinduced charge generation in pristine pentamethine cyanine salts

Jacques-Edouard Moser, Frank Nüesch, George Cameron Fish, Juan Manuel Moreno Naranjo

The mechanism of photoinduced symmetry-breaking charge separation in solid cyanine salts at the base of organic photovoltaic and optoelectronic devices is still debated. Here, we employ femtosecond transient absorption spectroscopy (TAS) to monitor the cha ...

2021