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Mohammad Ibrahim Dar

Cette personne a quitté l’EPFL

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Publications associées (63)

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High Open Circuit Voltage for Perovskite Solar Cells with S,Si-Heteropentacene-Based Hole Conductors

Michael Graetzel, Shaik Mohammed Zakeeruddin, Mohammad Ibrahim Dar, Neha Arora

High photovoltage in perovskite solar cells (PSCs) can be achieved by designing new hole transporting materials (HTMs) with relatively deeper energy levels of the highest occupied molecular orbital (HOMO). Here, we report on the synthesis of a new heteroac ...

WILEY-V C H VERLAG GMBH2018

Unravelling the structural complexity and photophysical properties of adamantyl-based layered hybrid perovskites

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ursula Röthlisberger, Ulf Anders Hagfeldt, Amita Ummadisingu, Mohammad Ibrahim Dar, Marko Mladenovic, Wolfgang Richard Tress, Farzaneh Jahanbakhshi, Paramvir Ahlawat, Brian Irving Carlsen, Yang Li, Jovana Milic, Algirdas Ducinskas

Layered hybrid perovskites comprising adamantyl spacer (A) cations based on the A(2)FA(n-1)Pb(n)I(3n+1)(n= 1-3, FA = formamidinium) compositions have recently been shown to act as promising materials for photovoltaic applications. While the corresponding p ...

Royal Society of Chemistry2020

Hill climbing hysteresis of perovskite-based solar cells: a maximum power point tracking investigation

Michael Graetzel, Shaik Mohammed Zakeeruddin, Norman Pellet, Mohammad Ibrahim Dar, Fabrizio Giordano, Joachim Maier

The surge of the power conversion efficiency of metal halide lead perovskite solar cells comes with concerns, such as the long-term ecotoxicity of lead compounds, their sensitivity toward moisture and oxygen, or the scarcity of some of their components. Mo ...

Wiley-Blackwell2017

Perovskite Solar Cells Yielding Reproducible Photovoltage of 1.20 V

Michael Graetzel, Shaik Mohammed Zakeeruddin, Mohammad Ibrahim Dar, Wolfgang Richard Tress, Neha Arora, Essa Awadh R Alharbi

High photovoltages and power conversion efficiencies of perovskite solar cells (PSCs) can be realized by controlling the undesired nonradiative charge carrier recombination. Here, we introduce a judicious amount of guanidinium iodide into mixed-cation and ...

2019

Quantum-Confined ZnO Nanoshell Photoanodes for Mesoscopic Solar Cells

Michael Graetzel, Mohammad Khaja Nazeeruddin, Aravind Kumar Chandiran, Aswani Yella, Chenyi Yi, Mojtaba Abdi Jalebi, Mohammad Ibrahim Dar

We present a photoanode for dye-sensitized solar cell (DSC) based on ZnO nanoshell deposited by atomic layer deposition at 150°C, on a mesoporous insulating template. An ultrathin layer of ZnO between 3 and 6 nm, which exhibits quantum confinement effect, ...

American Chemical Society2014

Unraveling the Impact of Rubidium Incorporation on the Transport-Recombination Mechanisms in Highly Efficient Perovskite Solar Cells by Small-Perturbation Techniques

Michael Graetzel, Shaik Mohammed Zakeeruddin, Mohammad Ibrahim Dar, Neha Arora

We applied intensity-modulated photocurrent spectroscopy (IMPS) and intensity-modulated photovoltage spectroscopy (IMVS) techniques to explore the effect of rubidium (Rb) incorporation into lead halide perovskite films on the photovoltaic parameters of per ...

American Chemical Society2017

Thermodynamically stabilized beta-CsPbI3-based perovskite solar cells with efficiencies > 18%

Michael Graetzel, Mohammad Ibrahim Dar

Although beta-CsPbI3 has a bandgap favorable for application in tandem solar cells, depositing and stabilizing beta-CsPbI3 experimentally has remained a challenge. We obtained highly crystalline beta-CsPbI3 films with an extended spectral response and enha ...

American Association for the Advancement of Science2019

Growth Engineering of CH3NH3PbI3 Structures for High-Efficiency Solar Cells

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

Controlling the growth of perovskite crystals has been one of the interesting strategies to mold their fundamental properties and exploit their potential in the fabrication of high performance solar cells. Herein, the impact of chloride on the conversion o ...

Wiley-VCH Verlag Berlin2016

High photovoltage in perovskite solar cells: New physical insights from the ultrafast transient absorption spectroscopy

Michael Graetzel, Shaik Mohammed Zakeeruddin, Mohammad Ibrahim Dar, Marius Franckevicius, Neha Arora

To understand the cause of the high open circuit photovoltage (VOC) achieved by todays' state of the art perovskite solar cells (PSCs), we examine formamidinium lead bromide CH(NH2)(2)PbBr3 films by ultrafast transient absorption spectroscopy (TAS). By usi ...

Elsevier2017

Hydrothermally processed CuCrO2 nanoparticles as an inorganic hole transporting material for low-cost perovskite solar cells with superior stability

Michael Graetzel, Shaik Mohammed Zakeeruddin, Mohammad Ibrahim Dar, Yuhang Liu, Seckin Akin

Despite the impressive photovoltaic performances of perovskite solar cells (PSCs) with a power conversion efficiency (PCE) beyond 22%, intensive studies are still required to overcome ongoing issues such as cost, stability, and hysteresis. Here, for the fi ...

Royal Society of Chemistry2018

Silver Bismuth Iodides for Photovoltaic Applications: Insights from Ab Initio Calculations and Experimental Analysis

Michael Graetzel, Ursula Röthlisberger, Mohammad Ibrahim Dar, Marko Mladenovic, Jingshan Luo, Jeong-Hyeok Im, Farzaneh Jahanbakhshi, Jovana Milic

American Chemical Society (ACS)2025

Investigation Regarding the Role of Chloride in Organic-Inorganic Halide Perovskites Obtained from Chloride Containing Precursors

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

As the photovoltaic performance of a device is strongly influenced by the morphology of perovskite, achieving precise control over the crystal formation of organic-inorganic halide perovskites synthesized in the ambience of chloride ions has garnered much ...

American Chemical Society2014

Triazatruxene-Based Hole Transporting Materials for Highly Efficient Perovskite Solar Cells

Michael Graetzel, Mohammad Khaja Nazeeruddin, Peng Gao, Peng Gao, Kasparas Rakstys, Gwénolé Jean Jacopin, Mohammad Ibrahim Dar, Antonio Abate

Four center symmetrical star-shaped hole transporting materials (HTMs) comprising planar triazatruxene core and electron-rich methoxy-engineered side arms have been synthesized and successfully employed in (FAPbI(3))(0.85)(MAPbBr(3))(0.15) perovskite solar ...

Amer Chemical Soc2015

Stable and Efficient Perovskite Solar Cells Based on Titania Nanotube Arrays

Michael Graetzel, Mohammad Khaja Nazeeruddin, Thomas Moehl, Peng Gao, 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

Controlled synthesis of TiO2 nanoparticles and nanospheres using a microwave assisted approach for their application in dye-sensitized solar cells

Michael Graetzel, Mohammad Khaja Nazeeruddin, Aravind Kumar Chandiran, Mohammad Ibrahim Dar

Rapid and facile synthesis of similar to 7 nm and similar to 100-400 nm nano-structures of anatase titania is achieved by exploiting the chemical nature of solvents through a microwave based approach. After using these nanostructures as a photoanode in dye ...

Royal Society of Chemistry2014

Inorganic hole conductor based perovskite photoelectric conversion device with high operational stability at long term

Michael Graetzel, Shaik Mohammed Zakeeruddin, Mohammad Ibrahim Dar, Neha Arora

The invention relates to an optoelectronic and/or photoelectrochemical device comprising a conductive support layer, n-type semiconductor, a sensitizer or light-absorber layer, a hole transporting layer, a spacer layer and a back contact, wherein the n-typ ...

2018

Tailored Amphiphilic Molecular Mitigators for Stable Perovskite Solar Cells with 23.5% Efficiency

Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Mohammad Ibrahim Dar, Xiong Li, Linfeng Pan, Zaiwei Wang, Yuhang Liu, Brian Irving Carlsen, Dan Ren, Marco Alejandro Ruiz Preciado, Bowen Yang, Felix Thomas Eickemeyer, Hongwei Zhu

Passivation of interfacial defects serves as an effective means to realize highly efficient and stable perovskite solar cells (PSCs). However, most molecular modulators currently used to mitigate such defects form poorly conductive aggregates at the perovs ...

Wiley2020

Guanidinium cations roles in perovskites solar cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Mohammad Ibrahim Dar, Neha Arora

AMER CHEMICAL SOC2018

Flexible high efficiency perovskite solar cells

Mohammad Khaja Nazeeruddin, Mohammad Ibrahim Dar, Cristina Roldán Carmona

Flexible perovskite based solar cells with power conversion efficiencies of 7% have been prepared on PET based conductive substrates. Extended bending of the devices does not deteriorate their performance demonstrating their suitability for roll to roll pr ...

Royal Society of Chemistry2014

Yttrium-substituted nanocrystalline TiO2 photoanodes for perovskite based heterojunction solar cells

Michael Graetzel, Mohammad Khaja Nazeeruddin, Nicolas Tétreault, Aravind Kumar Chandiran, Thomas Moehl, Peng Gao, Peng Gao, Peng Qin, Mohammad Ibrahim Dar

We report the use of Y3+-substituted TiO2 (0.5% Y-TiO2) in solid-state mesoscopic solar cells, consisting of CH3NH3PbI3 as the light harvester and spiro-OMeTAD as the hole transport material. A power conversion efficiency of 11.2% under simulated AM 1.5 fu ...

Royal Society of Chemistry2014