Publications by Pascal Comte | EPFL Graph Search

Dye-sensitized solar cells using cobalt electrolytes: the influence of porosity and pore size to achieve high-efficiency

Pascal Comte, Mohammad Khaja Nazeeruddin, Aswani Yella, Simon Mathew, Sadig Aghazada

Diffusion impediments in redox shuttles are a major limitation to realizing high power conversion efficiencies (PCEs) in dye sensitized solar cells (DSCs) using cobalt complexes. Mass transport limitations are strongly dependent on the pore size and the po ...

Royal Society of Chemistry2017

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

New pyrido[3,4-b]pyrazine-based sensitizers for efficient and stable dye-sensitized solar cells

Pascal Comte, Michael Graetzel, Jacques-Edouard Moser, Shaik Mohammed Zakeeruddin, Thomas Moehl, Mateusz Barnaba Wielopolski, Jiabao Yang

A series of new pyrido[3,4-b]pyrazine-based organic sensitizers (PP-I and APP-I–IV) containing different donors and p-spacers have been synthesized and employed in dye-sensitized solar cells (DSSCs). The absorption spectra properties of dyes are analysed b ...

Royal Soc Chemistry2014

Influence of the Donor Size in D-pi-A Organic Dyes for Dye-Sensitized Solar Cells

Pascal Comte, Michael Graetzel, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Joël Teuscher, Thomas Moehl, Chenyi Yi, Thomas Wesley Holcombe, Yongjoo Kim, Paramaguru Ganesan, Jiabao Yang

We report two new molecularly engineered push-pull dyes, i.e., YA421 and YA422, based on substituted quinoxaline as a pi-conjugating linker and bulky-indoline moiety as donor and compared with reported IQ4 dye. Benefitting from increased steric hindrance w ...

American Chemical Society2014

Acetylene-bridged dyes with high open circuit potential for dye-sensitized solar cells

Pascal Comte, Michael Graetzel, Shaik Mohammed Zakeeruddin, Thomas Moehl, Aswani Yella, Yongjoo Kim, Fabrizio Giordano, Chi-Lun Mai

A series of simple metal-free organic dyes MS1-MS3 have been designed and synthesized, and their optical, electrochemical, and photovoltaic properties were investigated. The molecular structures are based on a push-pull framework with a triphenylamine, nap ...

RSC Publishing2014

Thiadiazolo[3,4-c]pyridine Acceptor Based Blue Sensitizers for High Efficiency Dye-Sensitized Solar Cells

Pascal Comte, Michael Graetzel, Shaik Mohammed Zakeeruddin, Carole Graetzel, Robin Humphry-Baker, Joël Teuscher, Thomas Moehl, Chenyi Yi, Jiabao Yang

Two new [1,2,5]thiadiazolo[3,4-c]pyridine-containing D-A-pi-A organic dyes (PT-1 and PT-2) have been designed and synthesized for utilization in dye-sensitized solar cells. PT-2 sensitizer, which was synthesized by incorporating the 4,4-bis(2-ethylhexyl)-4 ...

American Chemical Society2014

Evaluating the critical thickness of TiO2 layer on insulating mesoporous templates for efficient current collection in dye-sensitized solar cells

Pascal Comte, Michael Graetzel, Mohammad Khaja Nazeeruddin, Robin Humphry-Baker, Aravind Kumar Chandiran, Chenyi Yi

In this paper, we present a way of utilizing thin and conformal overlayer of titanium dioxide on insulating mesoporous template as a photoanode for dye-sensitized solar cells (DSC). Different thicknesses of TiO2 ranging from 1 nm to 15 nm are deposited on ...

Wiley-Blackwell2013

Low temperature crystalline titanium dioxide by atomic layer deposition for dye-sensitized solar cells

Pascal Comte, Michael Graetzel, Mohammad Khaja Nazeeruddin, Aravind Kumar Chandiran, Leo-Philipp Heiniger, Aswani Yella, Morgan Mertens Stefik

Low temperature processing of dye-sensitized solar cells (DSC) is crucial to enable commercialization with low-cost, plastic substrates. Prior studies have focused on mechanical compression of premade particles on plastic or glass substrates, however, this ...

Amer Chemical Soc2013

Avoiding Diffusion Limitations in Cobalt(III/II)-Tris(2,2'-Bipyridine)-Based Dye-Sensitized Solar Cells by Tuning the Mesoporous TiO2 Film Properties

Pascal Comte, Michael Graetzel, Chenyi Yi, Hoi Nok Tsao

Dye-sensitized solar cells based on electrolytes containing cobalt complexes as redox shuttles typically suffer a major limitation in terms of slow diffusion of those couples through the mesoporous TiO2 film. This results in a drop of the photocurrent dens ...

Wiley-Blackwell2012

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

Stable dye-sensitized solar cells based on organic chromophores and ionic liquid electrolyte

Pascal Comte, Michael Graetzel, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin

A series of polyene-diphenylaniline based organic dyes (coded as D5, D7, D9 and D11) have been reported for the application in ionic liquid electrolyte based dye-sensitized solar cells. The effects of substitution of organic dyes on the photovoltaic perfor ...

2011

Effect of Sensitizer Adsorption Temperature on the Performance of Dye-Sensitized Solar Cells

Pascal Comte, Michael Graetzel, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Jean-David Décoppet, Peng Wang

Employing a mesoscopic titania photoanode whose bilayer structure was judiciously selected to fit the optoelectronic characteristics of the Ru-based heteroleptic complex Na-cis-Ru(4,4'-(5-hexyltiophen-2-yl)-2,2'-bipyridine)(4-carboxylic-acid-4'-carboxylate ...

2011

Doping a TiO2 Photoanode with Nb5+ to Enhance Transparency and Charge Collection Efficiency in Dye-Sensitized Solar Cells

Pascal Comte, Michael Graetzel, Shaik Mohammed Zakeeruddin, Aravind Kumar Chandiran

The optoelectronic properties of our benchmark nanocrystalline anatase TiO2 photoanode were modified by means of aliovalent doping with Nb5+. Even for a low doping level, the charge collection efficiency can be noticeably improved as a result of a higher e ...

American Chemical Society2010

Dye-Sensitized Solar Cells Employing a Single Film of Mesoporous TiO2 Beads Achieve Power Conversion Efficiencies Over 10%

Pascal Comte, Michael Graetzel, Leo-Philipp Heiniger

Dye-sensitized solar cells employing mesoporous TiO2 beads have demonstrated longer electron diffusion lengths and extended electron lifetimes over Degussa P25 titania electrodes due to the well interconnected, densely packed nanocrystalline TiO2 particles ...

American Chemical Society2010

Application of Cu(II) and Zn(II) coproporphyrins as sensitizers for thin film dye sensitized solar cells

Pascal Comte, Michael Graetzel, Jacques-Edouard Moser, Shaik Mohammed Zakeeruddin, Joël Teuscher, Davide Di Censo, Mingkui Wang, Leila Alibabaei

We synthesized the Cu(II) and Zn(II) complexes of the 2,7,12,17-tetrapropionic acid of 3,8,13,18-tetramethyl-21H,23H porphyrin (coproporphyrin-I) and successfully employed them as sensitizers in dye-sensitized solar cells. Copper(II) coproporphyrin-I exhib ...

Royal Society of Chemistry2010

Hierarchical TiO2 Photoanode for Dye-Sensitized Solar Cells

Pascal Comte, Michael Graetzel

Hierarchical or one-dimensional architectures are among the most exciting developments in material science these recent years We present a nanostructured TiO2 assembly combining these two concepts and resembling a forest composed of individual, high aspect ...

American Chemical Society2010

Ultrafast charge transfer through p-oligo(phenylene) bridges: effect of nonequilibrium vibrations

Serge Pelet, Bernard Wenger, Pascal Comte, Michael Graetzel, Jacques-Edouard Moser, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Joël Teuscher, Christophe Bauer

Electron transfers (ET) between a donor (D) and an acceptor (A) through a molecular bridge (B) are of great importance in biological systems, molecular electronics and molecular based light-energy conversion systems. Here, the back and the forward electron ...

Current Science Assoc // Indian Academy of Sciences2010

Regenerative PbS and CdS Quantum Dot Sensitized Solar Cells with a Cobalt Complex as Hole Mediator

Pascal Comte, Michael Graetzel, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Peter Chen, Takeru Bessho, Soo-Jin Moon, Kevin Sivula

Metal sulfide (PbS and CdS) quantum dots (QDs) were prepared over mesoporous TiO2 films by improved successive ionic layer adsorption and reaction (SILAR) processes. The as-prepared QD-sensitized electrodes were combined with a cobalt complex redox couple ...

2009

Increased light harvesting in dye-sensitized solar cells with energy relay dyes

Pascal Comte, Michael Graetzel, Mohammad Khaja Nazeeruddin, Jun Ho Yum

Conventional dye-sensitized solar cells have excellent charge collection efficiencies, high open-circuit voltages and good fill factors. However, dye-sensitized solar cells do not completely absorb all of the photons from the visible and near-infrared doma ...

Nature Publishing Group2009

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