Publications associées à Photocapacitance spectroscopy of InAlN nearly lattice-matched to GaN

Automated all-functionals infrared and Raman spectra

Infrared and Raman spectroscopies are ubiquitous techniques employed in many experimental laboratories, thanks to their fast and non-destructive nature able to capture materials' features as spectroscopic fingerprints. Nevertheless, these measurements freq ...

Nature Portfolio2024

Controlling crystal cleavage in focused ion beam shaped specimens for surface spectroscopy

Philip Johannes Walter Moll, Matthias Carsten Putzke, Andrew Scott Hunter

Our understanding of quantum materials is commonly based on precise determinations of their electronic spectrum by spectroscopic means, most notably angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling microscopy. Both require atomicall ...

Aip Publishing2024

Photogeneration of Hydrogen: Insights from a Pt(II)-Complex Incorporated into a Covalent Organic Framework

Paolo Costa, Federico De Biasi

Pt(II)-based molecular catalysts stand as a prototypical system in hydrogen evolution reactions (HER) owing to their consistently elevated activity levels. Their integration into heterogeneous systems thus provides an ideal platform to develop catalytic ma ...

Wiley-VCH Verlag2024

Bridging Native and Intrinsic Structures of Microhydrated Biomolecules by Cold Ion Spectroscopy

Andrei Zviagin

Solving native structures of such large molecules, like biomolecules, is often challenging, particularly due to the potentially infinite number of non-covalent interactions with water. In this thesis, we report the use of cold ion gas-phase action spectros ...

EPFL2023

Revealing the Structure of Tryptophan in Microhydrated Complexes by Cold Ion Spectroscopy

Oleg Boyarkine, Natalia Nagornova, Manuel Dömer, Andrei Zviagin, Ruslan Yamaletdinov

The geometry of biomolecules isolated in the gas phaseusuallydiffers substantially from their native structures in aqueous solution,which are the only ones truly relevant to life science. To connectthe high resolution of cold ion spectroscopy that can be a ...

2023

Single molecule fluorescence and phosphorescence studies using a scanning tunneling microscope

Abhishek Grewal

This thesis investigates novel single-molecule luminescence phenomena at their inherent, sub-molecular length scale. The microscopic understanding of luminescence processes will be crucial for the continued improvement of organic optoelectronic and semicon ...

EPFL2022

Efficient ab initio semiclassical dynamics for linear and nonlinear electronic spectroscopy

Tomislav Begusic

Molecular spectroscopy is an essential experimental technique in both fundamental physical sciences and applied research. For example, electronic spectroscopy, in which light induces a change in the electronic state of a molecule, is a powerful tool for st ...

EPFL2021

Broadband visible two-dimensional spectroscopy of molecular dyes

Majed Chergui, Andre Al Haddad, Lars-Hendrik Mewes, Rebecca Ann Ingle

Two-dimensional Fourier transform spectroscopy is a promising technique to study ultrafast molecular dynamics. Similar to transient absorption spectroscopy, a more complete picture of the dynamics requires broadband laser pulses to observe transient change ...

AMER INST PHYSICS2021

Structural and analytical identifications of biomolecules by cold ion spectroscopy of non-covalent complexes

Erik Saparbayev

Non-covalent interactions are ubiquitous in nature. The diversity and functionality of these interactions are employed by nature as a universal tool for building the molecular mechanism of life. Although weak, these interactions play a key role in both for ...

EPFL2021

Challenges and Applications to Operando and In Situ TEM Imaging and Spectroscopic Capabilities in a Cryogenic Temperature Range

Martial Duchamp, Vasiliki Tileli, Reinis Ignatans

In this Account, we describe the challenges and promising applications of transmission electron microscopy (TEM) imaging and spectroscopy at cryogenic temperatures. Our work focuses on two areas of application: the delay of electron-beam-induced degradatio ...

AMER CHEMICAL SOC2021

Direct observation of multiband transport in magnonic Penrose quasicrystals via broadband and phase-resolved spectroscopy

Dirk Grundler, Korbinian Baumgärtl, Vinayak Shantaram Bhat, Sho Watanabe, Mohammad Hamdi

Quasicrystals are aperiodically ordered structures with unconventional rotational symmetry. Their peculiar features have been explored in photonics to engineer bandgaps for light waves. Magnons (spin waves) are collective spin excitations in magnetically o ...

2021

Method and system for analysis of organic material by auto-cathodoluminescence

Hans Mattias Larsson, Marcin Stefan Zielinski

Analyzing isolated collagen gel samples of a rat-tail and bovine hide, we demonstrated in situ detection of spectrally deconvoluted auto-cathodoluminescence signatures of specific molecular content with precise spatial localization over a maximum field of ...

2020

Valorization of biomass derivatives through the conversion of phenol over silica-supported Mo-Re oxide catalysts

Ricardo Javier Serpell Carriquiry

Liquid-phase hydrodeoxygenation of phenol over silica-supported MoOx-ReOx catalysts was investigated at 300 degrees C and 5 MPa of H-2. Mixed-oxides catalysts with similar surface metal density (2.3 atoms of metal per nm(2) of SiO2) but different relative ...

2020

Electrons leave the flatland: out-of-plane charge dynamics in layered materials

Edoardo Martino

The goal of this thesis is to explore the "neglected" third dimension of layered materials, by studying the interlayer charge dynamics through dc conductivity, optical spectroscopy and ab-initio calculations. This project was designed to respond to the gro ...

EPFL2020

Electron energy loss spectroscopy of bulk gold with ultrasoft pseudopotentials and the Liouville-Lanczos method

Iurii Timrov

The implementation of ultrasoft pseudopotentials into time-dependent density-functional perturbation theory is detailed for both the Sternheimer approach and the Liouville-Lanczos (LL) method, and equations are presented in the scalar relativistic approxim ...

AMER PHYSICAL SOC2020

Quantitative intrinsic auto-cathodoluminescence can resolve spectral signatures of tissue-isolated collagen extracellular matrix

Jeffrey Alan Hubbell, Peter Frey, Hans Mattias Larsson, Elif Vardar, Marcin Stefan Zielinski, Ganesh Vythilingam

By analyzing isolated collagen gel samples, we demonstrated in situ detection of spectrally deconvoluted auto-cathodoluminescence signatures of specific molecular content with precise spatial localization over a maximum field of view of 300 mu m. Correlati ...

2019

Micro-focused MHz pink beam for time-resolved X-ray emission spectroscopy

Andre Al Haddad, Christoph Bostedt

The full radiation from the first harmonic of a synchrotron undulator (between 5 and 12 keV) at the Advanced Photon Source is microfocused using a stack of beryllium compound refractive lenses onto a fast-moving liquid jet and overlapped with a high-repeti ...

2019

Gas spectroscopy using low threshold mid-infrared radiation generated in Si3N4 waveguides

Tobias Kippenberg, Camille Sophie Brès, Hairun Guo, Davide Grassani, Eirini Tagkoudi

We report trace-gas absorption spectroscopy based on the efficient generation of a 3.05μm dispersive wave in a Si3N4 waveguide pumped by a 2.09 μm femtosecond mode-locked fiber laser ...

OSA Publishing2019

Bond-selective and surface-site-specific dissociation of methane on platinum

Ana Gutiérrez González

I present a molecular beam study of methane dissociation on differ-ent surface sites of several platinum single crystal surfaces (Pt(111), Pt(211), Pt(210), Pt(110)-(2x1)). The experiments were performed in a molecular beam/surface-science apparatus that c ...

EPFL2019

Using Gaussian process regression to simulate the vibrational Raman spectra of molecular crystals

Michele Ceriotti, Mariana Rossi Carvalho, Andrea Grisafi

Vibrational properties of molecular crystals are constantly used as structural fingerprints, in order to identify both the chemical nature and the structural arrangement of molecules. The simulation of these properties is typically very costly, especially ...

2019