Publications by Fabrizio Giordano

Xanthan-Based Hydrogel for Stable and Efficient Quasi-Solid Truly Aqueous Dye-Sensitized Solar Cell with Cobalt Mediator

Michael Graetzel, Guido Viscardi, Ulf Anders Hagfeldt, Fabrizio Giordano

Aqueous dye-sensitized solar cells (DSSCs) are emerging as a promising alternative to enhance both the lifetime and environmental friendliness of traditional DSSCs. Herein, a cobalt-based, jellified (with xanthan gum) aqueous electrolyte, leading to a valu ...

WILEY-V C H VERLAG GMBH2021

Solution-based heteroepitaxial growth of stable mixed cation/anion hybrid perovskite thin film under ambient condition via a scalable crystal engineering approach

Michael Graetzel, Shaik Mohammed Zakeeruddin, Fabrizio Giordano, Narges Yaghoobi Nia

The performance of perovskite solar cells is under direct control of the perovskite film quality and controlling the crystalinity and orientation of solution-processed perovskite film is a fundamental challenge. In this study, we present a scalable fabrica ...

Elsevier2020

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

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

Effect of Coordination Sphere Geometry of Copper Redox Mediators on Regeneration and Recombination Behavior in Dye-Sensitized Solar Cell Applications

Jacques-Edouard Moser, Shaik Mohammed Zakeeruddin, Joël Teuscher, Ulf Anders Hagfeldt, Marko Stojanovic, Fabrizio Giordano, Yasemin Saygili, Marina Freitag, Jan Tiepelt

The recombination of injected electrons with oxidized redox species and regeneration behavior of copper redox mediators are investigated for four copper complexes, [Cu(dmby)2]2+/1+ (dmby = 6,6′-dimethyl-2,2′- bipyridine), [Cu(tmby)2]2+/1+ (tmby = 4,4′,6,6′ ...

2018

Inter-Domain Charge Transfer as a Rationale for Superior Photovoltaic Performances of Mixed Halide Lead Perovskites

Jacques-Edouard Moser, Joël Teuscher, Eric Vauthey, Marine Eva Fedora Bouduban, Fabrizio Giordano

Organic-inorganic lead halide perovskites containing a mixture of iodide and bromide anions consistently perform better in donor-acceptor heterojunction solar cells than the standard methylammonium lead triiodide material. This observation is counterintuit ...

2018

Device and method for performing maximum power point tracking for photovoltaic devices in presence of hysteresis

Michael Graetzel, Shaik Mohammed Zakeeruddin, Norman Pellet, Fabrizio Giordano

A photovoltaic system including a solar cell having a hysteretic behavior; and a power device configured to extract a maximum power from the solar cell by forcing power oscillations of the power output by the solar cell. ...

2018

Mesoscopic Oxide Double Layer as Electron Specific Contact for Highly Efficient and UV Stable Perovskite Photovoltaics

Shaik Mohammed Zakeeruddin, Fabrizio Giordano, Mohammad Mahdi Tavakoli

American Chemical Society (ACS)2018

11% efficiency solid-state dye-sensitized solar cells with copper(II/I) hole transport materials

Jacques-Edouard Moser, Shaik Mohammed Zakeeruddin, Joël Teuscher, Ulf Anders Hagfeldt, Norman Pellet, Yiming Cao, Amita Ummadisingu, Fabrizio Giordano, Jingshan Luo, Yasemin Saygili, Marina Freitag

Solid-state dye-sensitized solar cells currently suffer from issues such as inadequate nanopore filling, low conductivity and crystallization of hole-transport materials infiltrated in the mesoscopic TiO2 scaffolds, leading to low performances. Here we rep ...

Nature Publishing Group2017

Significance of pi-bridge contribution in pyrido[3,4-b]pyrazine featured D-A-pi-A organic dyes for dye-sensitized solar cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Yelin Hu, Fabrizio Giordano, Xiaoyu Zhang, Zhongjin Shen

The 3,4-ethylenedioxythiophene (EDOT) pi-bridge is one of the most commonly used building blocks for sensitizers in dye-sensitized solar cells (DSSCs). We investigated its influence on the molecular structure, the photophysical and electrochemical properti ...

Chinese Chemical Soc2017

Dye-sensitized solar cells for efficient power generation under ambient lighting

Paul Liska, Jacques-Edouard Moser, Shaik Mohammed Zakeeruddin, Joël Teuscher, Ulf Anders Hagfeldt, Fabrizio Giordano, Yasemin Saygili, Xiaoyu Zhang, Marina Freitag

Solar cells that operate efficiently under indoor lighting are of great practical interest as they can serve as electric power sources for portable electronics and devices for wireless sensor networks or the Internet of Things. Here, we demonstrate a dye-s ...

Nature Publishing Group2017

The Role of Rubidium in Multiple-Cation-Based High-Efficiency Perovskite Solar Cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Mohammad Ibrahim Dar, Fabrizio Giordano, Neha Arora, Essa Awadh R Alharbi, Pankaj Kumar Yadav

Perovskite solar cells (PSCs) based on cesium (Cs)- and rubidium (Rb)-containing perovskite films show highly reproducible performance; however, a fundamental understanding of these systems is still emerging. Herein, this study has systematically investiga ...

Wiley-Blackwell2017

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

Cobalt and/or copper complexes for use as hole transport layer dopants to improve optoelectronic or photoelectrochemical devices

Michael Graetzel, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Julian Burschka, Fabrizio Giordano, Marina Freitag

This invention discloses a new class of dopants that allows easy tuning of the chem., phys., optical and/or electronic properties of the doping agent in order to carefully adapt it to the desired application, such as org. solar cells or solid state dye-sen ...

2016

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

Copper Phenanthroline as a Fast and High-Performance Redox Mediator for Dye-Sensitized Solar Cells

Michael Graetzel, Ulf Anders Hagfeldt, Fabrizio Giordano, Marina Freitag, Yan Hao

The most commonly used redox mediators in dye-sensitized solar cells (DSCs), iodide/triiodide and cobalt trisbipyridine (Co(bpy)(3)), were successfully replaced by bis (2,9-dimethy1-1,10-phenanthroline) copp er (I/H) (Cu(dmp)(2)). The use ...

American Chemical Society2016

A Computational and Experimental Study of Thieno[3,4-b]thiophene as a Proaromatic pi-Bridge in Dye-Sensitized Solar Cells

Michael Graetzel, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Fabrizio Giordano

Four D-pi-A dyes (D=donor, A=accpetor) based on a 3,4-thienothiophene pi-bridge were synthesized for use in dye-sensitized solar cells (DSCs). The proaromatic building block 3,4-thienothiophene is incorporated to stabilize dye excited-state oxidation poten ...

Wiley-Blackwell2016

Enhanced electronic properties in mesoporous TiO2 via lithium doping for high-efficiency perovskite solar cells

Michael Graetzel, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Fabrizio Giordano, Juan-Pablo Correa-Baena, Antonio Abate, Taisuke Matsui, Michael Saliba

Perovskite solar cells are one of the most promising photovoltaic technologies with their extraordinary progress in efficiency and the simple processes required to produce them. However, the frequent presence of a pronounced hysteresis in the current volta ...

Nature Publishing Group2016

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

Copper Bipyridyl Redox Mediators for Dye-Sensitized Solar Cells with High Photovoltage

Jacques-Edouard Moser, Shaik Mohammed Zakeeruddin, Nikolaos Vlachopoulos, Ladislav Kavan, Ulf Anders Hagfeldt, Norman Pellet, Yiming Cao, Fabrizio Giordano, Yasemin Saygili, Marina Freitag, Magnus Söderberg

Redox mediators play a major role determining the photocurrent and the photovoltage in dye-sensitized solar cells (DSCs). To maintain the photocurrent, the reduction of oxidized dye by the redox mediator should be significantly faster than the electron bac ...

American Chemical Society2016