Publications associées à Épitaxie en phase vapeur aux organométalliques

Direct high-temperature growth of GaN on Si using trimethylaluminum preflow enabling vertically-conducting heterostructures

Elison de Nazareth Matioli, Alessandro Floriduz

In this work, we demonstrate that GaN can be directly grown at high temperature on Si(111) substrates by metalorganic CVD without using any intentional AlN buffer, by simply employing a trimethylaluminum (TMAl) preflow. We found that n-GaN layers directly ...

Iop Publishing Ltd2024

Growth and Doping Mechanisms of III-V Nanostructures by Selective Area Epitaxy

Didem Dede

Selective area epitaxy (SAE), applied to semiconductor growth, allows tailored fabrication of intricate structures at the nanoscale with enhanced properties and functionalities. In the field of nanowires (NWs), it adds scalability by enabling the fabricati ...

EPFL2024

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

Long live(d) CsPbBr3 superlattices: colloidal atomic layer deposition for structural stability

Raffaella Buonsanti, Alexander Nicolas Chen, Philippe Benjamin Green, Victoria Lapointe

Superlattice formation afforded by metal halide perovskite nanocrystals has been a phenomenon of interest due to the high structural order induced in these self-assemblies, an order that is influenced by the surface chemistry and particle morphology of the ...

Royal Soc Chemistry2024

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

Pierre Christophe Lottigier

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

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

Advancing high-throughput combinatorial aging studies of hybrid perovskite thin films via precise automated characterization methods and machine learning assisted analysis

Christian Michael Wolff, Austin George Kuba, Alexander Wieczorek

To optimize material stability, automated high-throughput workflows are of increasing interest. However, many of those workflows either employ synthesis techniques not suitable for large-area depositions or are carried out in ambient conditions, which limi ...

Royal Society of Chemistry2024

From Layer-by-Layer Growth to Nanoridge Formation: Selective Area Epitaxy of GaAs by MOVPE

Anna Fontcuberta i Morral, Alok Rudra, Didem Dede, Valerio Piazza, Nicholas Paul Morgan, Vladimir Dubrovskii, Marie Sophie Sanglé-Ferrière, Ann-Kristin Stief

We outline the growth mechanismand shape evolution of GaAsnanoridges by selective area MOVPE with three well-identified, distinctstages of growth. ...

AMER CHEMICAL SOC2023

Voltage-driven Chemical Reactions Enable the Synthesis of Tunable Liquid Ga – Metal Nanoparticles

Raffaella Buonsanti, Anna Loiudice, Pascal Alexander Schouwink, Krishna Kumar, Coline Marie Agathe Boulanger, Valery Okatenko, Alexander Nicolas Chen

Nanosized particles of liquid metals are emerging materials which hold promise for applications spanning from microelectronics to catalysis. Yet, the knowledge of their chemical reactivity is largely unknown. Here, we study the reactivity of liquid Ga and ...

2023

Scalable Approaches to III-V Nanowires for Photodetection

Nicholas Paul Morgan

III-V semiconductor nanowires have unique properties that make them ideal for advanced photodetectors on inexpensive substrates. For example, they exhibit enhanced or polarization-dependent light absorption, they can form complex heterostructures, and thei ...

EPFL2023

Voltage-driven Reactivity of Liquid Ga and CuGa Nanoparticles for Electrocatalytic CO2 Reduction and Synthesis

Valery Okatenko

The rising atmospheric level of carbon dioxide, CO2, contributes to climate change and poses urgent need to find scalable solutions both to decrease its emissions and to be able to recycle it, if the goals of Paris Agreement to limit the temperature rise a ...

EPFL2023

Sinter-Resistant Nickel Catalyst for Lignin Hydrogenolysis Achieved by Liquid Phase Atomic Layer Deposition of Alumina

Jeremy Luterbacher, Songlan Sun, Farzaneh Talebkeikhah

Lignin hydrogenolysis is a key step in the sustainable production of renewable bio-based chemicals and fuels. Heterogeneous metal catalysts have led to high yields but they rapidly deactivate, notably due to nanoparticle sintering and carbonaceous deposit ...

2023

Surfactant behavior and limited incorporation of indium during in situ doping of GeSn grown by molecular beam epitaxy

Anna Fontcuberta i Morral, Andrea Giunto, Thomas Hagger, Louise Emma Webb

GeSn is a promising group-IV semiconductor material for on-chip Si photonics devices and high-mobility transistors. These devices require the use of doped GeSn regions, achieved preferably in situ during epitaxy. From the electronic valence point of view, ...

AMER PHYSICAL SOC2023

Investigating the Effect of Crystal Morphology on Optoelectronic Properties of Zinc Phosphide Thin Films via Optical-pump Terahertz Probe Spectroscopy

Elias Zsolt Stutz, Jean-Baptiste Leran, Mahdi Zamani, Rajrupa Paul, Simon Robert Escobar Steinvall, Mirjana Dimitrievska, Léa Buswell

Zinc phosphide ( Zn3P2) is a promising earth-abundant material for solar cell applications but calls for the further understanding of its optoelectronic properties. In this work, we perform contact-free and noninvasive optical-pump terahertz probe (OPTP) s ...

IEEE2023

GeSn as next-generation material for short-wave infrared single-photon detection

Andrea Giunto

In recent years, the automotive industry has aspired to bring self-driving vehicles to the general public and light detection and ranging (LiDAR) sensors have emerged as the preferred solution for car vision systems. At present, LiDAR technologies employ e ...

EPFL2023

GaN growth on ScAlMgO4 substrates via thermally-dewetted thin Al films

Elison de Nazareth Matioli, Alessandro Floriduz

In this note, we demonstrate the high-temperature growth of GaN on ScAlMgO4 substrates by metalorganic vapor phase epitaxy when a thin Al film is deposited ex situ on the ScAlMgO4 surface, prior to GaN growth. Mirror-like high-quality GaN epitaxial layers ...

IOP Publishing Ltd2022

Direct high-temperature growth of single-crystalline GaN on ScAlMgO4 substrates by metalorganic chemical vapor deposition

Elison de Nazareth Matioli, Alessandro Floriduz

In this note, we demonstrate direct high-temperature growth of single-crystalline GaN on c-plane ScAlMgO4 substrates by metalorganic chemical vapor deposition, without using low-temperature buffers. We found that a trimethylaluminium preflow was crucial to ...

IOP Publishing Ltd2022

Coherent Hole Transport in Selective Area Grown Ge Nanowire Networks

Anna Fontcuberta i Morral, Alok Rudra, Andrea Giunto, Santhanu Panikar Ramanandan, Nicholas Paul Morgan

Holes in germanium nanowires have emerged as a realistic platform for quantum computing based on spin qubit logic. On top of the large spin–orbit coupling that allows fast qubit operation, nanowire geometry and orientation can be tuned to cancel out charge ...

American Chemical Society (ACS)2022

Electrical Spectroscopy of Defect States in Synthetic 2D Materials

Yanfei Zhao

Two-dimensional (2D) materials such as graphene and transition metal dichalcogenide (TMDC) are considered as one of the most promising material platforms for future electronic devices, due to their ultra-thin thickness and fascinating electrical and optica ...

EPFL2022

Spectroscopy and dynamics at liquid water interfaces

Bruno Credidio

This thesis is a detailed description of three experimental investigations on aqueous interfaces. All projects made use of the microjet technology or the more recently developed flat-jet technique which enables the implementation of liquid water in vacuum ...

EPFL2022