Publications by Péter Kalman Péchy

Electron-Affinity-Triggered Variations on the Optical and Electrical Properties of Dye Molecules Enabling Highly Efficient Dye-Sensitized Solar Cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Péter Kalman Péchy, Ulf Anders Hagfeldt, Yiming Cao, Marko Stojanovic, Mohammad Ibrahim Dar, Yasemin Saygili, Weiwei Zhang, Yuhang Liu

The synthesis, characterization, and photovoltaic performance of a series of indacenodithiophene (IDT)-based D--A organic dyes with varying electron-accepting units is presented. By control of the electron affinity, perfectly matching energy levels were ac ...

Wiley-VCH Verlag GmbH2018

Cation Dynamics in Mixed-Cation (MA)(x)(FA)(1-x)PbI3 Hybrid Perovskites from Solid-State NMR

Michael Graetzel, Shaik Mohammed Zakeeruddin, Péter Kalman Péchy, Dominik Józef Kubicki, David Lyndon Emsley, Albert Hofstetter, Daniel Prochowicz

Mixed-cation organic lead halide perovskites attract unfaltering attention owing to their excellent photovoltaic properties. Currently, the best performing perovskite materials contain multiple cations and provide power conversion efficiencies up to around ...

2017

Thermal stability of the DSC ruthenium dye C106 in robust electrolytes

Michael Graetzel, Shaik Mohammed Zakeeruddin, Péter Kalman Péchy

We have investigated the thermal stability of the heteroleptic ruthenium complex C106 employed as a sensitizer in dye-sensitized solar cells. The C106 was adsorbed on TiO2 particles and exposed to 2 different iodide/triidode based redox electrolytes A and ...

Pergamon-Elsevier Science Ltd2014

Molecular-Scale Interface Engineering of Nanocrystalline Titania by Co-adsorbents for Solar Energy Conversion

Michael Graetzel, Shaik Mohammed Zakeeruddin, Robin Humphry-Baker, Péter Kalman Péchy, Mingkui Wang

The use of mixed self-assembled monolayers, combining hydrophobic co-adsorbents with the sensitizer, has been demonstrated to enhance the efficiency of dye-sensitized solar cells (DSCs). Herein, the influence of the anchoring groups of the co-adsorbents on ...

2012

High-voltage (1.8 V) tandem solar cell system using a GaAs/AlXGa(1-X)As graded solar cell and dye-sensitised solar cells with organic dyes having different absorption spectra

Pascal Comte, Michael Graetzel, Paul Liska, Péter Kalman Péchy, Jun Ho Yum

Stacked multijunction (tandem) solar cells have been prepared by mechanically stacking dye-sensitised solar cells (DSCs) and a GaAs/AlXGa(1-X)As graded solar cell (GGC) as the top and bottom cells, respectively. Three organic dyes with different absorption ...

2011

Four-electron oxygen reduction by Tetrathiafulvalene

Hubert Girault, Péter Kalman Péchy, Jérôme Florian Gonthier, Anne-Clémence Corminboeuf, Peiyu Ge, Astrid Johana Olaya Avendano

The four-electron reduction of oxygen by tetrathiafulvalene (TTF) in acidified 1,2-dichloroethane and at the acidified water/1,2-dichloroethane interface has been observed. Spectroscopy and ion transfer voltammetry results suggest that the reaction proceed ...

2011

Effect of anchoring groups in zinc phthalocyanine on the dye-sensitized solar cell performance and stability

Michael Graetzel, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Robin Humphry-Baker, Péter Kalman Péchy, Jun Ho Yum

We have designed and developed an unsymmetrical zinc phthalocyanine (TT9) sensitizer that consists of three tert-butyl and two carboxylic acid groups that act as "push'' and "pull'', respectively. The two carboxylic acid groups graft the sensitizer onto th ...

2011

High Excitation Transfer Efficiency from Energy Relay Dyes in Dye-Sensitized Solar Cells

Michael Graetzel, Mohammad Khaja Nazeeruddin, Péter Kalman Péchy, Jun Ho Yum

The energy relay dye, 4-(Dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM), was used with a near-infrared sensitizing dye, TT1, to increase the overall power conversion efficiency of a dye-sensitized solar cell (DSC) from 3.5% to 4.5%. Th ...

American Chemical Society2010

Modified surface

Michael Graetzel, Shaik Mohammed Zakeeruddin, Péter Kalman Péchy

The present invention relates to modified surfaces. The surfaces comprise an inorganic material on which a phosphinic acid derivative is adsorbed. The phosphinic acid thus turns out to be a new anchoring group useful for surface derivatisation. The inventi ...

2010

Polymer wiring of insulating electrode materials: An approach to improve energy density of lithium-ion batteries

Michael Graetzel, Shaik Mohammed Zakeeruddin, Péter Kalman Péchy, Qian Wang

The poor electronic conductivity of LiFePO4 has been one of the major issues impeding it from achieving high power and energy density lithium-ion batteries. In this communication, a novel polymer-wiring concept was proposed to improve the conduction of the ...

2009

Study of Dye-Sensitized Solar Cells by Scanning Electron Micrograph Observation and Thickness Optimization of Porous TiO2 Electrodes

Pascal Comte, Michael Graetzel, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Péter Kalman Péchy

2009

Passivation of nanocrystalline TiO2 junctions by surface adsorbed phosphinate amphiphiles enhances the photovoltaic performance of dye sensitized solar cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Péter Kalman Péchy, Mingkui Wang, Xuan Li

We report a new class of molecular insulators that electronically passivate the surface of nanocrystalline titania films for high performance dye sensitized solar cells (DSC). Using electrical impedance measurements we demonstrate that co-adsorption of din ...

2009

High-conversion-efficiency organic dye-sensitized solar cells with a novel indoline dye

Pascal Comte, Michael Graetzel, Paul Liska, Péter Kalman Péchy

An indoline dye (D205), the synthesis method of which is disclosed in this report, gave high-efficiency organic dye-sensitized solar cells (9.52%) using an anti-aggregation reagent (chenodeoxycholic acid). ...

Royal Society of Chemistry2008

Fabrication of screen-printing pastes from TiO2 powders for dye-sensitised solar cells

Pascal Comte, Michael Graetzel, Paul Liska, Mohammad Khaja Nazeeruddin, Péter Kalman Péchy, Peter Chen

2007

High energy lithium batteries by molecular wiring and targeting approaches

Michael Graetzel, Shaik Mohammed Zakeeruddin, Péter Kalman Péchy, Nicholas Evans, Qian Wang

2007

The Electronic Role of the TiO2 Light-Scattering Layer in Dye-Sensitized Solar Cells

Pascal Comte, Michael Graetzel, Paul Liska, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Robin Humphry-Baker, Péter Kalman Péchy, Raphaël Charvet

2007

Photovoltaic Characterization of Dye-sensitized Solar Cells: Effect of Device Masking on Conversion Efficiency

Pascal Comte, Michael Graetzel, Paul Liska, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Marie Jirousek, Péter Kalman Péchy, Raphaël Charvet

2006

High-Efficiency Organic-Dye-Sensitized Solar Cells Controlled by Nanocrystalline-TiO2 Electrode Thickness

Pascal Comte, Michael Graetzel, Paul Liska, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Robin Humphry-Baker, Péter Kalman Péchy

Wiley2006

Highly Efficient dye-sensitized solar cells based on carbon black counter electrodes

Pascal Comte, Michael Graetzel, Paul Liska, Mohammad Khaja Nazeeruddin, Robin Humphry-Baker, Péter Kalman Péchy, Takeru Bessho, Qian Wang

2006

High-efficiency (7.2%) flexible dye-sensitized solar cells with Ti-metal substrate for nanocrystalline-TiO2 photoanode

Pascal Comte, Michael Graetzel, Paul Liska, Mohammad Khaja Nazeeruddin, Guido Rothenberger, Shaik Mohammed Zakeeruddin, Péter Kalman Péchy

High-efficiency flexible dye-sensitized solar cells were fabricated with a Ti-metal foil substrate for photo anode and using a Pt-electrodeposited counter electrode on ITO/polyethylene naphthalate (ITO/PEN); these devices were characterized by incident pho ...

Royal Society of Chemistry2006