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

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, David Lyndon Emsley, Péter Kalman Péchy, Dominik Józef Kubicki, Daniel Prochowicz, Albert Hofstetter

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, Mingkui Wang, Robin Humphry-Baker, Péter Kalman Péchy

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

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

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

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, Jun Ho Yum, Robin Humphry-Baker, Péter Kalman Péchy

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, Jun Ho Yum, Péter Kalman Péchy

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, Qian Wang, Péter Kalman Péchy

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