Publications associées à Synthesis of wide atomically precise graphene nanoribbons from para-oligophenylene based molecular precursor

Additive Fabrication of Microsupercapacitors

Microsupercapacitors (with footprints from -mm up to -cm scale) have attracted attention for use as electrochemical energy storage devices to power wearables, IoT, and other small microsystems due to their high power density, excellent charge/discharge rev ...

EPFL2023

Full Solution Process of a Near-Infrared Light-Emitting Electrochemical Cell Based on Novel Emissive Ruthenium Complexes of 1,10-Phenanthroline-Derived Ligands and a Eutectic Alloy as the Top Electrode

Mohammad Khaja Nazeeruddin

Near-infrared luminescent materials have recently received considerable attention for a large number of applications, including in solid-state lighting, as bioimaging agents, as photovoltaic cells, and in the telecommunication industry. By adding diverse e ...

AMER CHEMICAL SOC2023

Transfer of Graphene under Ultra-High Vacuum

Darius Constantin Merk

This thesis reports on a novel method for graphene transfer that is fully UHV compatible, which has remained a challenge for a long time due to the necessity of supporting graphene for transfer and most often requiring supporting layer removal post-transfe ...

EPFL2022

Demonstrating and Unraveling a Controlled Nanometer-Scale Expansion of the Vacancy Defects in Graphene by CO2

Kumar Varoon Agrawal, Luis Francisco Villalobos Vazquez de la Parra, Kuang-Jung Hsu

A controlled manipulation of graphene edges and vacancies is desired for molecular separation, sensing and electronics applications. Unfortunately, available etching methods always lead to vacancy nucleation making it challenging to control etching. Herein ...

Wiley-VCH Verlag GmbH2022

Mass transport of water vapor and ions from Å-scale graphene nanopores

Wan-Chi Lee

Hydrodynamics at the nanoscale involves both fundamental study and application of fluid and mass transport phenomena in nanometer-sized confinements. Nanopores in single-layer graphene can be highly attractive for exploring the molecular transport of gas a ...

EPFL2022

Crystallization of Size-Selective Nanopores in Graphene for Gas Separation

Nanoporous single-layer graphene (N-SLG) membranes, owing to their single-atom thinness, have the potential to exceed the permeance and selectivity limits of gas separation membranes. However, two key issues in the top-down N-SLG synthesis need to be addre ...

EPFL2022

Tuning the tribological performance of plasma-treated hybrid layers of PEEK-GO-DLC

Roberto Guarino

Graphene and graphene oxide (GO)-based coatings are of great interest due to their mechanical, electrical and/or thermal performance that add functionalities to materials employed in many industrial and biomedical appli-cations. Hybrid diamond-like carbon ...

2022

Gas Separation Membranes with Atom-Thick Nanopores: The Potential of Nanoporous Single-Layer Graphene

Deepu Joseph Babu, Kumar Varoon Agrawal, Luis Francisco Villalobos Vazquez de la Parra, Kuang-Jung Hsu, Cédric Karel J Van Goethem

Gas separation is one of the most important industrial processes and is poised to take a larger role in the transition to renewable energy, e.g., carbon capture and hydrogen purification. Conventional gas separation processes involving cryogenic distillati ...

AMER CHEMICAL SOC2022

Long Spin Lifetime in Rare-Earth Single-Atom Magnets at Surfaces

Boris Sorokin

Further miniaturisation of magnetic storage devices requires an advent of new types of magnets, since classical ferromagnetic materials show lack of remanence at nano- and subnanoscale. A single atom can represent the smallest possible bit of information. ...

EPFL2022

Etching nanopores in single-layer graphene with a sub-angstrom resolution in molecular sieving

Shiqi Huang

Single-layer graphene (SLG) membranes, hosting molecular-sieving nanopores have been regarded as the ultimate gas separation membranes, attributing to the fact that they are the thinnest possible molecular barrier. However, the expected attractive performa ...

EPFL2021

Rapid screening of nanopore candidates in nanoporous single-layer graphene for selective separations using molecular visualization and interatomic potentials

Rohit Karnik, Luc Sébastien Bondaz

Nanoporous single-layer graphene is promising as an ideal membrane because of its extreme thinness, chemical resistance, and mechanical strength, provided that selective nanopores are successfully incorporated. However, screening and understanding the tran ...

AIP Publishing2021

Bottom-up synthesis of graphene films hosting atom-thick molecular-sieving apertures

Emad Oveisi, Mina Moradi, Kumar Varoon Agrawal, Shiqi Huang, Mostapha Dakhchoune, Luis Francisco Villalobos Vazquez de la Parra, Shaoxian Li, Kuang-Jung Hsu, Victor Carle Adrien Boureau, Kangning Zhao, Cédric Karel J Van Goethem

Incorporation of a high density of molecular-sieving nanopores in the graphene lattice by the bottom-up synthesis is highly attractive for high-performance membranes. Herein, we achieve this by a controlled synthesis of nanocrystalline graphene where incom ...

National Academy of Sciences2021

Polybenzimidazole copolymer derived lacey carbon film for graphene transfer and contamination removal strategies for imaging graphene nanopores

Kumar Varoon Agrawal, Shiqi Huang, Guangwei He, Mostapha Dakhchoune, Luis Francisco Villalobos Vazquez de la Parra, Wan-Chi Lee

The study of the nanometer-scale vacancy defects (nanopores) in graphene by transmission electron microscopy (TEM) is severely hindered by the presence of polymeric residues originating from the graphene-transfer-step to the TEM grid. The state-of-the-art ...

2020

Centimeter-scale gas-sieving nanoporous single-layer graphene membrane

Luc Sébastien Bondaz, Kumar Varoon Agrawal, Shiqi Huang, Guangwei He, Mostapha Dakhchoune, Wan-Chi Lee

High-permeance, molecular-sieving, nanoporous single-layer graphene (NSLG) membranes are highly promising for gas separation. However, the formation of cracks during the transfer of NSLG to a low-cost porous support is difficult to avoid. These cracks are ...

2020

Hydrogen sieving from intrinsic defects of benzene-derived single-layer graphene

Mina Moradi, Kumar Varoon Agrawal, Shiqi Huang, Mostapha Dakhchoune, Jing Zhao, Majharul Haque Khan

Single-layer graphene films, crystallized by chemical vapor deposition, host a low density of vacancy defects that are attractive for the size-sieving of molecules. The size and the density of such defects are a function of the growth temperature and the c ...

2019

Development of graphene-based ionizing radiation sensors

Davide Forti, Giovanni Borghi, Alberto Ciarrocchi

We present the first steps to develop radiation sensors based on the graphene field effect transistor technology. Such a sensor exploits the ambipolar behavior of graphene near its Dirac point and it is not dependent on collecting charges, but it senses io ...

ELSEVIER SCIENCE BV2019

Single-layer graphene membranes by crack-free transfer for gas mixture separation

Duncan Thomas Lindsay Alexander, Emad Oveisi, Andreas Züttel, Kumar Varoon Agrawal, Shiqi Huang, Guangwei He, Mostapha Dakhchoune, Wen Luo, Jing Zhao

The single-layer graphene film, when incorporated with molecular-sized pores, is predicted to be the ultimate membrane. However, the major bottlenecks have been the crack-free transfer of large-area graphene on a porous support, and the incorporation of mo ...

Nature Publishing Group2018

Fabrication and Study of Optical Properties of LEDs Based on GaN Micropyramids with a Ni/Au/Graphene Semi-Transparent Contact

Hua Zhang

The results of studies of technological conditions of formation of LEDs on the basis of an InGaN/GaN micropyramid in the core/shell geometry using a semi-transparent Ni/Au/graphene contact have been presented. The structures have been formed by the method ...

2018

Nonlinear THz spectroscopy and simulation of gated graphene

Matthias Gäumann, Juan Ramon Mosig, Michele Tamagnone

We studied the nonlinear optical properties of single layer graphene using high terahertz (THz) fields. With the use of a back gate and cooling down the sample to cryogenic temperatures we are able to spectrally probe the nonlinear THz properties of intrin ...

IOP PUBLISHING LTD2018

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