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Shaik Mohammed Zakeeruddin

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Publications associées (534)

Phenanthrene-Fused-Quinoxaline as a Key Building Block for Highly Efficient and Stable Sensitizers in Copper-Electrolyte-Based Dye-Sensitized Solar Cells

Michael Graetzel, Jacques-Edouard Moser, Shaik Mohammed Zakeeruddin, Etienne Christophe Socie, Weiwei Zhang, Brian Irving Carlsen, Yameng Ren, Huiyun Jiang, Yinghui Wu

Dye-sensitized solar cells (DSSCs) based on Cu-II/I bipyridyl or phenanthroline complexes as redox shuttles have achieved very high open-circuit voltages (V-OC, more than 1 V). However, their short-circuit photocurrent density (J(SC)) has remained modest. ...

Wiley-VCH Verlag GmbH2020

Reduced Graphene Oxide Improves Moisture and Thermal Stability of Perovskite Solar Cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Bowen Yang

Reduced graphene oxide (rGO) is a very stable material with tunable electronic properties dependent on its reduction level. Nevertheless, the incorporation of rGO into perovskite solar cells (PSCs) frequently demonstrates inconsistent results, and it plays ...

2020

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

Suppressing recombination in perovskite solar cells via surface engineering of TiO2 ETL

Michael Graetzel, Shaik Mohammed Zakeeruddin, Manoj Kumar, Pankaj Kumar Yadav, Daniel Prochowicz, Mohammad Mahdi Tavakoli

Hybrid perovskite solar cells (PSCs) have gained significant attention owing to their excellent physicochemical and photovoltaic properties. PSCs typically consist of a perovskite light absorber sandwiched between two carrier selective layers optimized wit ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Atomic-Level Microstructure of Efficient Formamidinium-Based Perovskite Solar Cells Stabilized by 5-Ammonium Valeric Acid Iodide Revealed by Multinuclear and Two-Dimensional Solid-State NMR

Michael Graetzel, Jacques-Edouard Moser, Shaik Mohammed Zakeeruddin, Ursula Röthlisberger, Marine Eva Fedora Bouduban, Marko Mladenovic, Fabrizio Giordano, Dominik Józef Kubicki, David Lyndon Emsley, Farzaneh Jahanbakhshi, Essa Awadh R Alharbi, Daniel Prochowicz, Anwar Qasem M Alanazi, Jovana Milic, Dan Ren

Chemical doping of inorganic–organic hybrid perovskites is an effective way of improving the performance and operational stability of perovskite solar cells (PSCs). Here we use 5-ammonium valeric acid iodide (AVAI) to chemically stabilize the structure of ...

2019

A partially-planarised hole-transporting quart-p-phenylene for perovskite solar cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Wolfgang Richard Tress, Michael Saliba

Herein, we describe the synthesis of a hole transporting material based on a partially planarised quart-p-phenylene core incorporating tetraketal and diphenylamine substituents that show optimal energy levels and solubility for perovskite solar cell applic ...

Royal Society of Chemistry2019

A tandem redox system with a cobalt complex and 2-azaadamantane-N-oxyl for fast dye regeneration and open circuit voltages exceeding 1 V

Michael Graetzel, Jacques-Edouard Moser, Shaik Mohammed Zakeeruddin, Nikolaos Vlachopoulos, Ulf Anders Hagfeldt, Heewon Bahng, Natalie Flores Diaz

A new tandem electrolyte composed of two redox pairs, the organic radical 2-azaadamantane-N-oxyl (AZ) and the well-known redox pair Co(bpy)(3) was investigated in dye sensitized solar cells. Importantly, an increase in V-OC was achieved using the ...

Royal Society of Chemistry2019

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

Synergistic Crystal and Interface Engineering for Efficient and Stable Perovskite Photovoltaics

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Michael Saliba, Philippe Jürgen Holzhey, Pankaj Kumar Yadav, Mohammad Mahdi Tavakoli

The presence of bulk and surface defects in perovskite light harvesting materials limits the overall efficiency of perovskite solar cells (PSCs). The formation of such defects is suppressed by adding methylammonium chloride (MACl) as a crystallization aid ...

WILEY-V C H VERLAG GMBH2019

Atomic-level passivation mechanism of ammonium salts enabling highly efficient perovskite solar cells

Michael Graetzel, Jacques-Edouard Moser, Shaik Mohammed Zakeeruddin, Fabrizio Giordano, Dominik Józef Kubicki, Jingshan Luo, Andrés Burgos Caminal, David Lyndon Emsley, Brennan James Walder, Essa Awadh R Alharbi, Anwar Qasem M Alanazi, Alexander Roland Uhl

The high conversion efficiency has made metal halide perovskite solar cells a real break-through in thin film photovoltaic technology in recent years. Here, we introduce a straight-forward strategy to reduce the level of electronic defects present at the i ...

Nature Research2019

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

A peri-Xanthenoxanthene Centered Columnar-Stacking Organic Semiconductor for Efficient, Photothermally Stable Perovskite Solar Cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Peng Wang, Yang Li, Yang Li, Rui Zhu

Modulating the structure and property of hole-transporting organic semiconductors is of paramount importance for high-efficiency and stable perovskite solar cells (PSCs). This work reports a low-cost peri-xanthenoxanthene based small-molecule P1, which is ...

WILEY-V C H VERLAG GMBH2019

Doping and phase segregation in Mn2+- and Co2+-doped lead halide perovskites from Cs-133 and H-1 NMR relaxation enhancement

Michael Graetzel, Shaik Mohammed Zakeeruddin, Dominik Józef Kubicki, Arthur César Pinon, David Lyndon Emsley, Albert Hofstetter, Gabriele Stevanato, Daniel Prochowicz

Lead halide perovskites belong to a broad class of compounds with appealing optoelectronic and photovoltaic properties. Doping with transition metal ions such as Mn2+ and Co2+ has recently been reported to substantially enhance luminescence and stability o ...

Royal Society of Chemistry2019

Perovskite Solar Cells Based on Oligotriarylamine Hexaarylbenzene as Hole-Transporting Materials

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Mona Shasti

A cobalt-catalyzed cyclotrimerization of bis(aryl)alkyne is used as an innovative tool to obtain hole-transport materials (HTMs). The novel HTM containing six units of oligotriarylamine (HAB1), characterized by UV-vis, cyclic voltammetry, DFT, and thermogr ...

AMER CHEMICAL SOC2019

Site-selective Synthesis of -[70]PCBM-like Fullerenes: Efficient Application in Perovskite Solar Cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Jiyoun Seo, Seckin Akin

We report on the site-selective synthesis of PCBM-like [70]fullerene site-isomers, where the elusive -site-isomers are, for the first time, the major product in a (cyclo)addition chemical reaction involving [70]fullerene. The reaction involves an straightf ...

WILEY-V C H VERLAG GMBH2019

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

Sequential catalysis enables enhanced C-C coupling towards multi-carbon alkenes and alcohols in carbon dioxide reduction: a study on bifunctional Cu/Au electrocatalysts

Michael Graetzel, Shaik Mohammed Zakeeruddin, Dan Ren, Jing Gao

Electrochemical reduction of carbon dioxide (CO2) to multi-carbon products such as ethylene, ethanol and n-propanol offers a promising path for utilization of excessive CO2 and energy storage. Oxide-derived Cu electrodes are among the best electrocatalysts ...

ROYAL SOC CHEMISTRY2019

Dopant-Free Hole-Transporting Polymers for Efficient and Stable Perovskite Solar Cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Wolfgang Richard Tress, Michael Saliba

A series of novel polymers (P1P6) derived from the combination of different units (including thiophene, triarylamine, and spirobifluorene) were successfully synthesized, completely characterized, and used as hole-transporting materials (HTMs) for perovskit ...

American Chemical Society2019

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

SnS Quantum Dots as Hole Transporter of Perovskite Solar Cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Xiaofei Dong, Peng Wang, Zaiwei Wang, Yuhang Liu, Yang Li, Dan Ren, Yang Li

Perovskite solar cells have achieved comparable power conversion efficiencies as commercial silicon cells, making the issue of long-term operation stability as the most critical scientific factor toward industrial realization. In this work, we introduce Sn ...

AMER CHEMICAL SOC2019

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