Publications by Mohammad Ibrahim Dar

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

Champion Device Architectures for Low-Cost and Stable Single-Junction Perovskite Solar Cells

Michael Graetzel, Thomas Paul Baumeler, Mohammad Ibrahim Dar, Neha Arora

High power conversion efficiencies (PCE), low energypayback time(EPBT), and low manufacturing costs render perovskite solar cells(PSCs) competitive; however, a relatively low operational stabilityimpedes their large-scale deployment. In addition, state-of- ...

AMER CHEMICAL SOC2023

Molecular Origin of the Asymmetric Photoluminescence Spectra of CsPbBr3 at Low Temperature

Michael Graetzel, Ursula Röthlisberger, Gwénolé Jean Jacopin, Mohammad Ibrahim Dar, Ariadni Boziki

CsPbBr3 has received wide attention due to its superior emission yield and better thermal stability compared to other organic-inorganic lead halide perovskites. In this study, through an interplay of theory and experiments, we investigate the molecular ori ...

2021

Quantifying Stabilized Phase Purity in Formamidinium-Based Multiple-Cation Hybrid Perovskites

Michael Graetzel, Shaik Mohammed Zakeeruddin, Thomas Paul Baumeler, Mohammad Ibrahim Dar, Neha Arora

A promising approach for the production of highly efficient and stable hybrid perovskite solar cells is employing mixed-ion materials. Remarkable performances have been reached by materials comprising a stabilized mixture of methylammonium (MA(+)) and form ...

2021

A Fully Printable Hole-Transporter-Free Semi-Transparent Perovskite Solar Cell

Michael Graetzel, Shaik Mohammed Zakeeruddin, Norman Pellet, Mohammad Ibrahim Dar

Perovskite solar cells (PSCs) have gained tremendous attention owing to their promising photovoltaic performance, surpassing all the alternative technologies based on solution-processed materials. PSCs displaying record efficiencies contain hole transporti ...

WILEY-V C H VERLAG GMBH2021

Minimizing the Trade-Off between Photocurrent and Photovoltage in Triple-Cation Mixed-Halide Perovskite Solar Cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Mojtaba Abdi Jalebi, Thomas Paul Baumeler, Mohammad Ibrahim Dar, Neha Arora, Ryusuke Uchida, Yuhang Liu, Seckin Akin

Its lower bandgap makes formamidinium lead iodide (FAPbI(3)) a more suitable candidate for single-junction solar cells than pure methylammonium lead iodide (MAPbI(3)). However, its structural and thermodynamic stability is improved by introducing a signifi ...

2020

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, Yang Li, 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

Stabilization of Highly Efficient and Stable Phase-Pure FAPbI(3)Perovskite Solar Cells by Molecularly Tailored 2D-Overlayers

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Mohammad Ibrahim Dar, Jiyoun Seo, Yuhang Liu, Seckin Akin, Jiahuan Zhang, Felix Thomas Eickemeyer, Hong Zhang, Hongwei Zhu

As a result of their attractive optoelectronic properties, metal halide APbI(3)perovskites employing formamidinium (FA(+)) as the A cation are the focus of research. The superior chemical and thermal stability of FA(+)cations makes alpha-FAPbI(3)more suita ...

Wiley-VCH Verlag GmbH2020

Cyclopentadithiophene-Based Hole-Transporting Material for Highly Stable Perovskite Solar Cells with Stabilized Efficiencies Approaching 21%

Michael Graetzel, Shaik Mohammed Zakeeruddin, Gwénolé Jean Jacopin, Mohammad Ibrahim Dar, Michael Bauer, Neha Arora, Ryusuke Uchida, Yuhang Liu, Seckin Akin

There is an urge to develop new hole-transporting materials (HTMs) for perovskite solar cells (PSCs), which can yield comparable power conversion efficiencies (PCEs) yet mitigate the issue of stability associated with the state-of-the-art HTM Spiro-MeOTAD. ...

AMER CHEMICAL SOC2020

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

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

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

Formamidinium-Based Dion-Jacobson Layered Hybrid Perovskites: Structural Complexity and Optoelectronic Properties

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, Yang Li, Algirdas Ducinskas

Layered hybrid perovskites have emerged as a promising alternative to stabilizing hybrid organic-inorganic perovskite materials, which are predominantly based on Ruddlesden-Popper structures. Formamidinium (FA)-based Dion-Jacobson perovskite analogs are de ...

2020

New Strategies for Defect Passivation in High-Efficiency Perovskite Solar Cells

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

Lead halide perovskite solar cells now show excellent efficiencies and encouraging levels of stability. Further improvements in performance require better control of the trap states which are considered to be associated with vacancies and defects at crysta ...

WILEY-V C H VERLAG GMBH2019

Atomistic Mechanism of the Nucleation of Methylammonium Lead Iodide Perovskite from Solution

Michael Graetzel, Ursula Röthlisberger, Michele Parrinello, Mohammad Ibrahim Dar, Paramvir Ahlawat

In the ongoing intense quest to increase the performance of perovskite solar cells, optimizing the morphology of perovskite material has become imperative to achieve high power conversion efficiencies. Despite the fact that nucleation plays a key role in c ...

ACS2019

Ultrahydrophobic 3D/2D fluoroarene bilayer-based water-resistant perovskite solar cells with efficiencies exceeding 22%

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Mohammad Ibrahim Dar, Neha Arora, Linfeng Pan, Ryusuke Uchida, Yuhang Liu, Jovana Milic, Alexander Roland Uhl, Seckin Akin

Preventing the degradation of metal perovskite solar cells (PSCs) by humid air poses a substantial challenge for their future deployment. We introduce here a two-dimensional (2D) A(2)PbI(4) perovskite layer using pentafluoro-phenylethylammonium (FEA) as a ...

2019

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, Pankaj Kumar Yadav

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

Low-Cost and Highly Efficient Carbon-Based Perovskite Solar Cells Exhibiting Excellent Long-Term Operational and UV Stability

Michael Graetzel, Shaik Mohammed Zakeeruddin, Thomas Paul Baumeler, Mohammad Ibrahim Dar, Neha Arora, Ryusuke Uchida, Yuhang Liu, Seckin Akin

Today's perovskite solar cells (PSCs) mostly use components, such as organic hole conductors or noble metal back contacts, that are very expensive or cause degradation of their photovoltaic performance. For future large-scale deployment of PSCs, these comp ...

2019

Charge extraction via graded doping of hole transport layers gives highly luminescent and stable metal halide perovskite devices

Michael Graetzel, Mojtaba Abdi Jalebi, Mohammad Ibrahim Dar, Zahra Andaji Garmaroudi

One source of instability in perovskite solar cells (PSCs) is interfacial defects, particularly those that exist between the perovskite and the hole transport layer (HTL). We demonstrate that thermally evaporated dopant-free tetra-cene (120 nm) on top of t ...

2019

Dual effect of humidity on cesium lead bromide: enhancement and degradation of perovskite films

Michael Graetzel, Mohammad Ibrahim Dar, Simone Meloni

CsPbBr3 perovskite is highly desired to fabricate many optoelectronic devices: high photovoltage solar cells, tandem solar cells, light-emitting diodes, lasers, photodetectors, field effect transistors etc. However, to realize these applications, resistanc ...

Royal Society of Chemistry2019

Bifunctional Organic Spacers for Formamidinium-Based Hybrid Dion-Jacobson Two-Dimensional Perovskite Solar Cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Amita Ummadisingu, Mohammad Ibrahim Dar, Jeong-Hyeok Im, Jiyoun Seo, Peng Wang, Hui-Seon Kim, Yuhang Liu, Yang Li, Jovana Milic, Yang Li

Three-dimensional (3D) perovskite materials display remarkable potential in photovoltaics owing to their superior solar-to-electric power conversion efficiency, with current efforts focused on improving stability. Two-dimensional (2D) perovskite analogues ...

AMER CHEMICAL SOC2019

Ruddlesden–Popper Phases of Methylammonium-Based Two-Dimensional Perovskites with 5-Ammonium Valeric Acid AVA2MAn–1PbnI3n+1 with n = 1, 2, and 3

Michael Graetzel, Ursula Röthlisberger, Negar Ashari Astani, Mohammad Ibrahim Dar, Marko Mladenovic, Farzaneh Jahanbakhshi, Anwar Qasem M Alanazi

2019