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Mohammad Ibrahim Dar

Cette personne n’est plus à l’EPFL

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Publications associées (65)

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, Pankaj Kumar Yadav

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

Air Processed Inkjet Infiltrated Carbon Based Printed Perovskite Solar Cells with High Stability and Reproducibility

Michael Graetzel, Shaik Mohammed Zakeeruddin, Syed Ghufran Hashmi, Mohammad Ibrahim Dar, Xiong Li

Carbon based perovskite solar cells are fabricated for the first time in a room temperature environment by employing inkjet infiltration of perovskite precursor ink. The fabricated perovskite solar cells exhibit impressive performance reproducibility with ...

Wiley2017

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

A wire shaped coaxial photovoltaic solar cell

Michael Graetzel, Mohammad Khaja Nazeeruddin, Carlos Perez, Mohammad Ibrahim Dar

A wire shaped coaxial photovoltaic solar cell comprising: a conductive core wire shaped support (401), a nanostructured semiconductor scaffold layer (402), one or more successive perovskite layers (403), an optionally provided hole transporting material la ...

2017

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

High Open-Circuit Voltage: Fabrication of Formamidinium Lead Bromide Perovskite Solar Cells Using Fluorene-Dithiophene Derivatives as Hole-Transporting Materials

Michael Graetzel, Mohammad Khaja Nazeeruddin, Paul Gratia, Gwénolé Jean Jacopin, Mohammad Ibrahim Dar, Sadig Aghazada, Neha Arora, Filippo de Angelis

Four different fluorene dithiophene derivative-based hole-transporting materials (HTMs) (SO7-10) have been synthesized via a facile route and were successfully used in the fabrication of formamidinium lead bromide perovskite solar cells. Detailed character ...

Amer Chemical Soc2016

Weakly Conjugated Hybrid Zinc Porphyrin Sensitizers for Solid-State Dye-Sensitized Solar Cells

Mohammad Khaja Nazeeruddin, Christian Ludwig, Peng Qin, Kasparas Rakstys, Mohammad Ibrahim Dar, Hany ElBatal

Molecularly engineered weakly conjugated hybrid porphyrin systems are presented as efficient sensitizers for solid-state dye-sensitized solar cells. By incorporating the quinolizino acridine and triazatruxene based unit as the secondary light-harvester as ...

Wiley-Blackwell2016

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

Impact of a Mesoporous Titania-Perovskite Interface on the Performance of Hybrid Organic-Inorganic Perovskite Solar Cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Mojtaba Abdi Jalebi, Mohammad Ibrahim Dar, Fabrizio Giordano

We report on the optimization of the interfacial properties of titania in mesoscopic CH3NH3PbI3 solar cells. Modification of the mesoporous TiO2 film by TiCl4 treatment substantially reduced the surface traps, as is evident from the sharpness of the absorp ...

Amer Chemical Soc2016

Intrinsic and Extrinsic Stability of Formamidinium Lead Bromide Perovskite Solar Cells Yielding High Photovoltage

Shaik Mohammed Zakeeruddin, Norman Pellet, Mojtaba Abdi Jalebi, Gwénolé Jean Jacopin, Mohammad Ibrahim Dar, Fabrizio Giordano, Neha Arora

We report on both the intrinsic and the extrinsic stability of a formamidinium lead bromide [CH(NH2)(2)PbBr3 = FAPbBr(3)] perovskite solar cell that yields a high photovoltage. The fabrication of FAPbBr(3) devices, displaying an outstanding photo voltage o ...

American Chemical Society2016

Origin of unusual bandgap shift and dual emission in organic-inorganic lead halide perovskites

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ursula Röthlisberger, Gwénolé Jean Jacopin, Mohammad Ibrahim Dar, Simone Meloni, Neha Arora, Ariadni Boziki

Emission characteristics of metal halide perovskites play a key role in the current widespread investigations into their potential uses in optoelectronics and photonics. However, a fundamental understanding of the molecular origin of the unusual blueshift ...

2016

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

Michael Graetzel, Mohammad Khaja Nazeeruddin, 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 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

Light Harvesting and Charge Recombination in CH3NH3PbI3 Perovskite Solar Cells Studied by Hole Transport Layer Thickness Variation

Michael Graetzel, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Robin Humphry-Baker, Mohammad Ibrahim Dar, Nevena Vaskova Marinova, Wolfgang Richard Tress

A tailored optimization of perovskite solar cells requires a detailed understanding of the processes limiting the device efficiency. Here, we study the role of the hole transport layer (HTL) spiro-MeOTAD and its thickness in a mesoscopic TiO2-based solar c ...

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

A Novel Oligomer as a Hole Transporting Material for Efficient Perovskite Solar Cells

Michael Graetzel, Mohammad Khaja Nazeeruddin, Nicolas Tétreault, Peng Gao, Peng Qin, Mohammad Ibrahim Dar

(Figure Presented) A polytriarylamine-based oligomer is reported as a hole transporting material and its application in solid-state CH3NH3PbI3 based heterojunction solar cells is described. It yields a power conversion efficiency of 12.0% under 99.6 mW cm- ...

Wiley-VCH Verlag Berlin2015

Improved performance and stability of perovskite solar cells by crystal crosslinking with alkylphosphonic acid omega-ammonium chlorides

Michael Graetzel, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Manuel Tschumi, Chenyi Yi, Mohammad Ibrahim Dar, Xiong Li, Jingshan Luo

In the past few years, organic-inorganic halide perovskites have rapidly emerged as promising materials for photovoltaic applications, but simultaneously achieving high performance and long-term stability has proved challenging. Here, we show a one-step so ...

Nature Publishing Group2015

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

Michael Graetzel, Mohammad Khaja Nazeeruddin, 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

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 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

Strong Photocurrent Amplification in Perovskite Solar Cells with a Porous TiO2 Blocking Layer under Reverse Bias

Michael Graetzel, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Thomas Moehl, Leo-Philipp Heiniger, Mohammad Ibrahim Dar, Konrad Domanski, Fabrizio Giordano, Yonghui Lee, Jeong-Hyeok Im

We investigate two different types of TiO2 blocking layer (BL) deposition techniques commonly used in solid-state methylammonium lead triiodide perovskite (MaPbI(3))-based solar cells. Although these BLs lead to similar photovoltaic device performance, the ...

Amer Chemical Soc2014

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