Publications by Neha Arora | EPFL Graph Search

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

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

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

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

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

Digestive-Ripening-Facilitated Nanoengineering of Diverse Bimetallic Nanostructures

Neha Arora

From an ingenious methodology for obtaining monodispersity, digestive ripening has advanced to become an outstanding solution-based synthesis route to realizing various bimetallic heterostructures. This feature article attempts to provide an overview of th ...

AMER CHEMICAL SOC2019

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

Halide Versus Nonhalide Salts: The Effects of Guanidinium Salts on the Structural, Morphological, and Photovoltaic Performances of Perovskite Solar Cells

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

The impacts of halide and nonhalide sources of guanidinium cations, including guanidinium chloride (GCl) ((NH2)(3)CCl) and guanidinium thiocyanate (GTC) ((NH2)(3)CSCN), are comparatively analyzed on the structural, morphological, and photophysical properti ...

WILEY-V C H VERLAG GMBH2019

Electrochemical Characterization of CuSCN Hole-Extracting Thin Films for Perovskite Photovoltaics

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

CuSCN thin films (optimized previously for perovskite photovoltaics) are deposited on glass, F:SnO2 (FTO), Au, glass-like carbon (GC), and reduced graphene oxide (rGO). They exhibit capacitive charging in an electrochemical window from ca. -0.3 to 0.2 V vs ...

AMER CHEMICAL SOC2019

Reduced Graphene Oxide as a Stabilizing Agent in Perovskite Solar Cells

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

One of the most challenging obstacles to commercialization of perovskite solar cells (PSCs) is their instability toward environmental conditions. An emerging solution to overcome these challenges relies on graphene-based composites, in particular, solution ...

WILEY2018

Influence of the Nature of A Cation on Dynamics of Charge Transfer Processes in Perovskite Solar Cells

Shaik Mohammed Zakeeruddin, Mohammad Ibrahim Dar, Neha Arora, Pankaj Kumar Yadav

2018

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

Michael Graetzel, Shaik Mohammed Zakeeruddin, Mohammad Ibrahim Dar, Amaresh Mishra, 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

Insights about the Absence of Rb Cation from the 3D Perovskite Lattice: Effect on the Structural, Morphological, and Photophysical Properties and Photovoltaic Performance

Michael Graetzel, Shaik Mohammed Zakeeruddin, Silvia Binet, Gwénolé Jean Jacopin, Mohammad Ibrahim Dar, Neha Arora, Ryusuke Uchida

Efficiencies >20% are obtained from the perovskite solar cells (PSCs) employing Cs+ and Rb+ based perovskite compositions; therefore, it is important to understand the effect of these inorganic cations specifically Rb+ on the properties of perovskite struc ...

WILEY-V C H VERLAG GMBH2018

Kinetics of Ion-Exchange Reactions in Hybrid Organic-Inorganic Perovskite Thin Films Studied by In Situ Real-Time X-ray Scattering

Michael Graetzel, Mohammad Ibrahim Dar, Neha Arora

The exchange of ions in hybrid organic inorganic perovskites with the general formula APbX(3) (A = MA, FA; X = I, Cl, Br) is studied in five different systems using in situ real-time grazing incident X-ray diffraction (GIXD). In systems where the organic c ...

AMER CHEMICAL SOC2018

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

Guanidinium cations roles in perovskites solar cells

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

AMER CHEMICAL SOC2018

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

Function Follows Form: Correlation between the Growth and Local Emission of Perovskite Structures and the Performance of Solar Cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Gwénolé Jean Jacopin, Mohammad Ibrahim Dar, Neha Arora

Understanding the relationship between the growth and local emission of hybrid perovskite structures and the performance of the devices based on them demands attention. This study investigates the local structural and emission features of CH3NH3PbI3, CH3NH ...

Wiley-Blackwell2017