Publications related to Structural and optical properties of high quality zinc-blende/wurtzite GaAs nanowire heterostructures

III-N blue-emitting epi-structures with high densities of dislocations: Fundamental mechanisms for efficiency improvement and applications

Since the dawn of humanity, human beings seeked to light their surroundings for their well-being, security and development. The efficiency of ancient lighting devices, e.g. oil lamps or candles, was in the order of 0.03-0.04% and jumped to 0.4-0.6% with th ...

EPFL2024

Mapping orthorhombic domains with geometrical phase analysis in rare-earth nickelate heterostructures

Jean-Marc Triscone, Duncan Thomas Lindsay Alexander, Bernat Mundet

Most perovskite oxides belong to the Pbnm space group, composed of an anisotropic unit cell, A-site antipolar displacements, and oxygen octahedral tilts. Mapping the orientation of the orthorhombic unit cell in epitaxial heterostructures that consist of at ...

Aip Publishing2024

Electron-beam based nanoscale quantum controls

Hoda Shirzad

Advancing quantum technologies depends on the precise control of individual quantum systems, the so-called qubits, and the exploitation of their quantum properties. Nowadays, expanding the number of qubits to be entangled is at the core of the developments ...

EPFL2024

Microsecond Time-Resolved Cryo-Electron Microscopy

Oliver Florian Harder

Recently, single-particle cryo-electron microscopy emerged as a technique capable of determining protein structures at near-atomic resolution and resolving protein dynamics with a temporal resolution ranging from second to milliseconds. This thesis describ ...

EPFL2024

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

Polydopamine-coated photoautotrophic bacteria for improving extracellular electron transfer in living photovoltaics

Fabian Fischer, Ardemis Anoush Boghossian, Charlotte Elisabeth Marie Roullier, Melania Reggente, Mohammed Mouhib, Patricia Brandl, Hanxuan Wang

Living photovoltaics are microbial electrochemical devices that use whole cell–electrode interactions to convert solar energy to electricity. The bottleneck in these technologies is the limited electron transfer between the microbe and the electrode surfac ...

2024

Investigation of room-temperature single-photon emitters in GaN-based materials and GaN/AlN quantum dots

Johann Nicolaï Stachurski

Over the past decade, quantum photonics platforms aiming at harnessing the fundamental properties of single particles, such as quantum superposition and quantum entanglement, have flourished. In this context, single-photon emitters capable of operating at ...

EPFL2024

Beyond the coupled distortion model: structural analysis of the single domain cupredoxin AcoP, a green mononuclear copper centre with original features

Luciano Andres Abriata

Cupredoxins are widely occurring copper-binding proteins with a typical Greek-key beta barrel fold. They are generally described as electron carriers that rely on a T1 copper centre coordinated by four ligands provided by the folded polypeptide. The discov ...

Royal Soc Chemistry2024

Advanced Silicon and SWIR Single-Photon Avalanche Diodes: Design, Simulation, and Characterization

Ekin Kizilkan

Low-level light detection with high spatial and timing accuracy is a growing area of interest by virtue of applications such as light detection and ranging (LiDAR), biomedical imaging, time-resolved Raman spectroscopy, and quantum applications. Single-phot ...

EPFL2024

Structural study of nickelate based heterostructures

Jean-Marc Triscone, Duncan Thomas Lindsay Alexander, Bernat Mundet, Chih-Ying Hsu

Heterostructures consisting of SmNiO3 and NdNiO3 alternating layers with additional LaAlO3 spacer layers were grown and fully characterized by means of x-ray diffraction, atomic force microscopy, and scanning transmission electron microscopy. A change in t ...

Aip Publishing2024

Towards Scalable Electronics: Synthetic 2D Materials for Large-Area 2D Circuit Integration

Zhenyu Wang

In the past decades, a significant increase of the transistor density on a chip has led to exponential growth in computational power driven by Moore's law. To overcome the bottleneck of traditional von-Neumann architecture in computational efficiency, effo ...

EPFL2024

Room-Temperature Quantum Optomechanics and Free-Electron Quantum Optics

Guanhao Huang

Quantum optics studies how photons interact with other forms of matter, the understanding of which was crucial for the development of quantum mechanics as a whole. Starting from the photoelectric effect, the quantum property of light has led to the develop ...

EPFL2024

Ultra-high quantum coherent and scalable superconducting circuit optomechanics, from topological lattices to quantum storage

Amir Youssefi

Mechanical oscillators can exhibit modes with ultra-low energy dissipation and compact form factors due to the slow velocity of acoustic waves, and are already used in applications ranging from timing to wireless filters. Over the past decade, novel ways i ...

EPFL2024

Controlled Formation of Nanoribbons and Their Heterostructures via Assembly of Mass-Selected Inorganic Ions

Klaus Kern

Control of nanomaterial dimensions with atomic precision through synthetic methods is essential to understanding and engineering of nanomaterials. For single-layer inorganic materials, size and shape controls have been achieved by self-assembly and surface ...

Wiley-V C H Verlag Gmbh2024

Unique corrosion behavior of an archaeological Roman iron ring: Microchemical characterization and thermodynamic considerations

Stefano Mischler, Laura Brambilla

The corrosion mechanisms of a Roman iron bezel ring were investigated by in-depth characterization of its uncommon corrosion pattern and thermodynamic modelling. A silver foil and altered glass remnants were identified, covered with thick strata of magneti ...

2024

Composition and Element Distribution Mapping of γ′ and γ" Phases of Inconel 718 by High-Resolution Scanning Transmission Electron Microscopy and X-ray Energy-Dispersive Spectrometry

Philippe Buffat

The main strengthening mechanism for Inconel 718 (IN718), a Ni-based superalloy, is precipitation hardening by gamma ' and gamma '' particles. It is thus essential, for good alloy performance, that precipitates with the desired chemical composition have ad ...

MDPI2024

Measuring electrical properties in semiconductor devices by pixelated STEM and off-axis electron holography (or convergent beams vs. plane waves)

Victor Carle Adrien Boureau

We demonstrate the use of both pixelated differential phase contrast (DPC) scanning transmission electron microscopy (STEM) and off-axis electron holography (EH) for the measurement of electric fields and assess the advantages and limitations of each techn ...

Pergamon-Elsevier Science Ltd2024

Study of growth-induced point defects and their impact on InGaN-based optoelectronic devices

Yao Chen

GaN exhibits a decomposition tendency for temperatures far below its melting point and common growth temperatures used in metal-organic vapour phase epitaxy (MOVPE).This characteristic is known to be a major obstacle for realising GaN bulk substrate. There ...

EPFL2024

Microstructure - Electrochemical Surface Reactivity Relationship of Electrochemically Grown Manganese Oxides Films

Roberto Cestaro

This Thesis provides a comprehensive and correlative investigation of the microstructure, chemical state, and electrochemical reactivity of manganese oxide (MnOx) films, aiming to gain a deeper understanding of the deposition and dissolution mechanism of M ...

EPFL2024

Tailoring p-Type Behavior in ZnO Quantum Dots through Enhanced Sol–Gel Synthesis: Mechanistic Insights into Zinc Vacancies

Jacques-Edouard Moser, Andrea Cannizzo, Etienne Christophe Socie, Camila Bacellar Cases Da Silveira, Victoria Kabanova

The synthesis and control of properties of p-type ZnO is crucial for a variety of optoelectronic and spintronic applications; however, it remains challenging due to the control of intrinsic midgap (defect) states. In this study, we demonstrate a synthetic ...

2024