Publications de Thomas Moehl | EPFL Graph Search

Triarylamine-based hydrido-carboxylate rhenium(i) complexes as photosensitizers for dye-sensitized solar cells

Ulf Anders Hagfeldt, Thomas Moehl, Kazuteru Nonomura, Lorenzo Veronese

Two new dyes based on a dinuclear rhenium complex and (E)-3-(5-(4-(bis(2,4-dibutoxy-[1,1-biphenyl]-4-yl)amino)phenyl)thiophen-2-yl)-2-cyanoacrylic acid (namely D35) have been investigated as sensitizers for dye sensitized solar cells (DSSCs). Two different ...

ROYAL SOC CHEMISTRY2019

Photovoltaic and Amplified Spontaneous Emission Studies of High-Quality Formamidinium Lead Bromide Perovskite Films

Benoît Marie Joseph Deveaud, Mohammad Khaja Nazeeruddin, Thomas Moehl, Mahmoud Saeed Qaid Mohammad Hezam, Peng Gao, Gwénolé Jean Jacopin, Mohammad Ibrahim Dar, Wolfgang Richard Tress, Neha Arora

This study demonstrates the formation of extremely smooth and uniform formamidinium lead bromide (CH(NH2)(2)PbBr3 = FAPbBr(3)) films using an optimum mixture of dimethyl sulfoxide and N,N-dimethylformamide solvents. Surface morphology and phase purity of t ...

Wiley-Blackwell2016

Photodetector

Mohammad Khaja Nazeeruddin, Thomas Moehl, Konrad Domanski, Jeong-Hyeok Im

The present invention concerns a device for room temperature reverse-bias operation photo-detection. The device comprising: - a planar first electrode extending in a planar direction; - a second electrode positioned above the first electrode in a direction ...

2016

Influence of the Adsorption of Phycocyanin on the Performance in DSS Cells: and Electrochemical and QCM Evaluation

Michael Graetzel, Jean-David Décoppet, Thomas Moehl

The influence of some coadsorbents and different pH values on the efficiency of DSS cells assembled with phycocyanin was evaluated using quartz crystal microbalance (QCM) and electrochemical techniques as impedance spectroscopy (EIS) and cyclic voltammetry ...

2016

Ionic polarization-induced current–voltage hysteresis in CH3NH3PbX3 perovskite solar cells

Michael Graetzel, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Ursula Röthlisberger, Thomas Moehl, Peng Gao, Yonghui Lee, Simone Meloni, Wolfgang Richard Tress, Marius Franckevicius, Michael Saliba

CH3NH3PbX3 (MAPbX(3)) perovskites have attracted considerable attention as absorber materials for solar light harvesting, reaching solar to power conversion efficiencies above 20%. In spite of the rapid evolution of the efficiencies, the understanding of b ...

Nature Research2016

Covalent Immobilization of a Molecular Catalyst on Cu2O Photocathodes for CO2 Reduction

Michael Graetzel, Marcel Roland Schreier, Thomas Moehl, Peng Gao, Matthew Thomas Mayer, Jingshan Luo

Sunlight-driven CO2 reduction is a promising way to close the anthropogenic carbon cycle. Integrating light harvester and electrocatalyst functions into a single photo electrode, which converts solar energy and CO2 directly into reduced carbon species, is ...

American Chemical Society2016

Unraveling the Dual Character of Sulfur Atoms on Sensitizers in Dye-Sensitized Solar Cells

Jacques-Edouard Moser, Mohammad Khaja Nazeeruddin, Joël Teuscher, Thomas Moehl, Aswani Yella, Peng Gao, Sadig Aghazada

Cyclometalated ruthenium sensitizers have been synthesized that differ with number of thiophene units on the auxiliary ligands. Sensitizers possessing four (SA25, SA246, and SA285) or none (SA282) sulfur atoms in their structures, were tested in solar cell ...

Amer Chemical Soc2016

Understanding the rate-dependent J-V hysteresis, slow time component, and aging in CH3NH3PbI3 perovskite solar cells: the role of a compensated electric field

Michael Graetzel, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Thomas Moehl, Nevena Vaskova Marinova, Wolfgang Richard Tress

In this work we show that the rate-dependent hysteresis seen in current-voltage scans of CH3NH3PbI3 perovskite solar cells is related to a slow field-induced process that tends to cancel the electric field in the device at each applied bias voltage. It is ...

Royal Soc Chemistry2015

Working Principles of Perovskite Photodetectors: Analyzing the Interplay Between Photoconductivity and Voltage-Driven Energy-Level Alignment

Michael Graetzel, Mohammad Khaja Nazeeruddin, Thomas Moehl, Konrad Domanski, Wolfgang Richard Tress, Michael Saliba

Organic-inorganic lead halide perovskites have recently received significant attention as active materials for high-performance photovoltaics and photo-detectors. However, the understanding of their operation mechanism remains limited. High-gain, low-volta ...

Wiley-V C H Verlag Gmbh2015

Stable and Efficient Perovskite Solar Cells Based on Titania Nanotube Arrays

Michael Graetzel, Mohammad Khaja Nazeeruddin, Thomas Moehl, Peng Gao, Peng Qin, Mohammad Ibrahim Dar, Neha Arora

Highly ordered 1D TiO2 nanotube arrays are fabricated and applied as nanocontainers and electron transporting material in CH3NH3PbI3 perovskite solar cells. The optimized device shows a power conversion efficiency of 14.8%, and improved stability under an ...

Wiley-V C H Verlag Gmbh2015

Long-Range π-Conjugation in Phenothiazine-containing Donor-Acceptor Dyes for Application in Dye-Sensitized Solar Cells

Michael Graetzel, Jacques-Edouard Moser, Shaik Mohammed Zakeeruddin, Carole Graetzel, Thomas Moehl, Mateusz Barnaba Wielopolski, Yuxiang Yu, Jinhyun Kim

Four organic donor–π-bridge–acceptor dyes containing phenothiazine as a spacer and cyanoacrylic acid as an acceptor were synthesized and tested as sensitizers in dye-sensitized solar cells (DSCs). The influence of iodide- and cobalt-based redox electrolyte ...

Wiley-VCH Verlag Berlin2015

Investigation of electrodeposited cobalt sulphide counter electrodes and their application in next-generation dye sensitized solar cells featuring organic dyes and cobalt-based redox electrolytes

Michael Graetzel, Mohammad Khaja Nazeeruddin, Thomas Moehl, Julien Edouard Frey, Simon Mathew

Cobalt sulphide (CoS) films are potentiodynamically deposited on fluorine-doped tin oxide (FTO) coated glass substrates employing one, three and five sweep cycles (CoS-I, CoS-III and CoS-V respectively). Analysis of the CoS-III film by impedance spectrosco ...

Elsevier Science Bv2015

Efficient screen printed perovskite solar cells based on mesoscopic TiO2/Al2O3/NiO/ carbon architecture

Michael Graetzel, Shaik Mohammed Zakeeruddin, Mingkui Wang, Thomas Moehl

We present efficient perovskite solar cells using a mesoscopic TiO2/Al2O3/NiO/carbon structure as framework. The CH(3)NH(3)Pbl(3)-based device with quadruple-layer architecture achieves a power conversion efficiency of 15.03% under AM 1.5G illumination. De ...

Elsevier Science Bv2015

Electron Kinetics in Dye Sensitized Solar Cells Employing Anatase with (101) and (001) Facets

Pascal Comte, Michael Graetzel, Mohammad Khaja Nazeeruddin, Ladislav Kavan, Thomas Moehl, Aswani Yella

Two phase-pure nanocrystalline anatase materials differing in the exposed crystal facets (001) or (101) are studied by electrochemical impedance spectroscopy and by transient photovoltage and photocurrent decay in dye sensitized solar cells. A larger chemi ...

Elsevier2015

Robust High-performance Dye-sensitized Solar Cells Based on Ionic Liquid-sulfolane Composite Electrolytes

Michael Graetzel, Shaik Mohammed Zakeeruddin, Jean-David Décoppet, Paul Joseph Dyson, Thomas Moehl, Pui Shan Genevieve Lau

Novel ionic liquid-sulfolane composite electrolytes based on the 1,2,3-triazolium family of ionic liquids were developed for dye-sensitized solar cells. The best performing device exhibited a short-circuit current density of 13.4 mA cm(-2), an open-circuit ...

Nature Publishing Group2015

Photovoltaic behaviour of lead methylammonium triiodide perovskite solar cells down to 80 K

Michael Graetzel, Shaik Mohammed Zakeeruddin, Hua Zhang, Mingkui Wang, Thomas Moehl

We have tested the photovoltaic metrics of CH3NH3PbI3 perovskite solar cells over a wide temperature range from 80-360 K. Our investigation reveals that the open-circuit voltage reaches a maximum value at about 200 K close to the phase transition from tetr ...

Royal Society of Chemistry2015

Nanowire Perovskite Solar Cell

Michael Graetzel, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Norman Pellet, Thomas Moehl, Peng Gao, Jingshan Luo, Jeong-Hyeok Im, Marius Franckevicius

Organolead iodide perovskite, CH3NH3PbI3, was prepared in the form of nanowire by means of a small quantity of aprotic solvent in two-step spin-coating procedure. One-dimensional nanowire perovskite with the mean diameter of 100 nm showed faster carrier se ...

American Chemical Society2015

Understanding the Impact of Bromide on the Photovoltaic Performance of CH3NH3PbI3 Solar Cells

Michael Graetzel, Mohammad Khaja Nazeeruddin, Thomas Moehl, Mojtaba Abdi Jalebi, Mohammad Ibrahim Dar, Neha Arora

An optimum amount of lead bromide (1%) can enhance the power conversion efficiency of CH3NH3PbI3-xBrx (where x approximate to 0) devices from 14.7% to 16.9% without altering the bandgap of the perovskite material. ...

Wiley-V C H Verlag Gmbh2015

Porphyrin Sensitizers Bearing a Pyridine-Type Anchoring Group for Dye-Sensitized Solar Cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Jean-David Décoppet, Thomas Moehl, Chi-Lun Mai

Three novel efficient donor-acceptor porphyrins, MH1-MH3, with a pyridine-type acceptor and anchoring group were synthesized and their optical, electrochemical, and photovoltaic properties investigated. Replacing the commonly used 4-carboxyphenyl anchoring ...

Amer Chemical Soc2015

Loading of mesoporous titania films by CH3NH3PbI3 perovskite, single step vs. sequential deposition

Michael Graetzel, Carole Graetzel, Thomas Moehl, Jeannette Medina Kadro

Infiltration of mesoporous TiO2 scaffolds by CH3NH3PbI3 is more complete when using sequential compared to single step deposition processing and avoids formation of disordered capping layers affording greatly improved performance of perovskite based photov ...

Royal Society of Chemistry2015