Publications associées à Paramètre cristallin

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

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

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

Zn3P2 as an earth-abundant photovoltaic material: from growth to device

Rajrupa Paul

The development of cost-effective and earth-abundant semiconducting materials is imperative for the sustainable deployment of photovoltaic technology. Zinc phosphide (Zn3P2) is a promising candidate for terawatt-scale electricity generation. It has a near- ...

EPFL2023

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

Deep defects in InGaN LEDs: modeling the impact on the electrical characteristics

Nicolas Grandjean, Jean-François Carlin, Camille Haller

Deep defects have a fundamental role in determining the electro-optical characteristics and in the efficiency of InGaN light-emitting diodes (LEDs). However, modeling their effect on the electrical characteristics of the LED is not straightforward. ...

SPIE-INT SOC OPTICAL ENGINEERING2022

p-NiO Junction Termination Extensions for High Voltage Vertical GaN Devices

Elison de Nazareth Matioli, Remco Franciscus Peter van Erp, Luca Nela, Riyaz Mohammed Abdul Khadar, Catherine Erine, Taifang Wang, Alessandro Floriduz, Pirouz Sohi, Reza Soleiman Zadeh Ardebili

In this paper, we illustrate the use of RF-sputtered p-NiO to fabricate Junction Termination Extensions (JTEs) for high-performance vertical GaN-on-Si Schottky Barrier Diodes (SBDs). The GaN epitaxial structures were grown on 6-inch Si wafers by MOCVD. The ...

IEEE2021

Molecular Origin of the Asymmetric Photoluminescence Spectra of CsPbBr3 at Low Temperature

Michael Graetzel, Ursula Röthlisberger, Ariadni Boziki, Mohammad Ibrahim Dar, Gwénolé Jean Jacopin

CsPbBr3 has received wide attention due to its superior emission yield and better thermal stability compared to other organic-inorganic lead halide perovskites. In this study, through an interplay of theory and experiments, we investigate the molecular ori ...

2021

GaN vertical power devices on silicon substrates

Riyaz Mohammed Abdul Khadar

Gallium Nitride (GaN) is a wonder material which has widely transformed the world by enabling energy-efficient white light-emitting diodes. Over the past decade, GaN has also emerged as one of the most promising materials for developing power devices which ...

EPFL2021

Diamond diffractive optics-recent progress and perspectives

Niels Quack, Gergely Huszka, Sichen Mi, Marcell Kristof Kiss

Diamond is an exceptional material that has recently seen a remarkable increase in interest in academic research and engineering since high-quality substrates became commercially available and affordable. Exploiting the high refractive index, hardness, las ...

WALTER DE GRUYTER GMBH2021

Quasi-vertical GaN-on-Si reverse blocking power MOSFETs

Elison de Nazareth Matioli, Riyaz Mohammed Abdul Khadar, Chao Liu, Alessandro Floriduz, Reza Soleiman Zadeh Ardebili

We demonstrate quasi-vertical reverse blocking (RB) MOSFETs on 6.7 mu m thick GaN grown on a 6 inch Si substrate by metalorganic chemical vapor deposition. The RB capability was achieved by replacing the ohmic drain with a quasi-vertical Schottky drain, re ...

IOP PUBLISHING LTD2021

Real- and Q-space travelling: multi-dimensional distribution maps of crystal-lattice strain (epsilon(044)) and tilt of suspended monolithic silicon nanowire structures

Yusuf Leblebici, Antonia Neels, Alex Dommann, Zuhal Tasdemir, Simone Dolabella

Silicon nanowire-based sensors find many applications in micro- and nano-electromechanical systems, thanks to their unique characteristics of flexibility and strength that emerge at the nanoscale. This work is the first study of this class of micro- and na ...

INT UNION CRYSTALLOGRAPHY2020

Band alignment at beta-Ga2O3/III-N (III = Al, Ga) interfaces through hybrid functional calculations

Alfredo Pasquarello, Sai Lyu

The band alignment and the chemical bonding at the beta -Ga2O3/AlN and beta -Ga2O3/GaN interfaces are studied through hybrid functional calculations. We construct realistic slab models with III-O (III = Al, Ga) bonds dominating the chemical bonding at both ...

2020

Measuring the Optical Absorption of Single Nanowires

Anna Fontcuberta i Morral, Wonjong Kim, Simon Robert Escobar Steinvall

In this work we present a method to quantitatively measure the optical absorption of single nanowires that can be applied over a wide range of temperatures and with a high enough sensitivity to enable the measurement of below-band-gap absorption (as well a ...

American Physical Society (APS)2020

van der Waals Epitaxy of Earth-Abundant Zn3P2 on Graphene for Photovoltaics

Anna Fontcuberta i Morral, Roland Logé, Cyril Cayron, Elias Zsolt Stutz, Jean-Baptiste Leran, Shreyas Sanjay Joglekar, Mahdi Zamani, Simon Robert Escobar Steinvall, Rajrupa Paul, Nicolas Philippe Laurent Humblot

Earth-abundant semiconducting materials are a potential solution for large-scale deployment of solar cells at a lower cost. Zinc phosphide (Zn3P2) is one such Earth-abundant material with optoelectronic properties suitable for photovoltaics. Herein, we rep ...

2020

Integrated gallium phosphide nonlinear photonics

Tobias Kippenberg, Dalziel Joseph Wilson, Miles Henry Anderson

Gallium phosphide (GaP) is an indirect-bandgap semiconductor used widely in solid-state lighting. Despite numerous intriguing optical properties-including large chi ((2)) and chi ((3)) coefficients, a high refractive index (>3) and transparency from visibl ...

Nature Publishing Group2020

Nanostructured alloys light the way to silicon-based photonics

Anna Fontcuberta i Morral

Silicon used for electronics has a cubic crystal lattice, which makes the material unsuitable for photonics applications. A method for producing germanium and silicon-germanium alloys that have hexagonal lattices offers a solution. ...

NATURE PUBLISHING GROUP2020

Progress in Violet Light-Emitting Diodes Based on ZnO/GaN Heterojunction

Eric Feltin, Mauro Mosca

Progress in light-emitting diodes (LEDs) based on ZnO/GaN heterojunctions has run into several obstacles during the last twenty years. While both the energy bandgap and lattice parameter of the two semiconductors are favorable to the development of such de ...

MDPI2020

Measurement and prediction of the transformation strain that controls ductility and toughness in advanced steels

William Curtin, Helena Van Swygenhoven, Francesco Maresca, Efthymios Polatidis

New-generation multi-phase martensitic steels derive their high strength from the body-centered cubic (BCC) phase and high toughness from transformation of the metastable face-centered cubic (FCC) austenite that transforms into martensite upon loading. In ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Variant selection in martensitic steels

Annick Pauline Baur

The martensitic phase transformation in steel is one of the most famous solid state transformation because of its contribution in the development of the modern industry. This transformation from a face-centered cubic (FCC) high temperature phase, called th ...

EPFL2019

Stronger Reductive Environment in Solvothermal Synthesis Leads to Improved Ga Doping Efficiency in ZnO Nanocrystals and Enhanced Plasmonic Absorption

Reinis Ignatans

The key parameter for degenerated semiconductor oxide plasmonic nanocrystals is the doping level. Hydrothermal and solvothermal approaches are considered to be less effective toward achieving high concentration of aliovalent donor dopants in a host oxide w ...

Wiley-VCH Verlag2019

Indirect tail states formation by thermal-induced polar fluctuations in halide perovskites

Michael Graetzel, Nripan Mathews, Qiang Xu, Bing Wu

Halide perovskites possess enormous potential for various optoelectronic applications. Presently, a clear understanding of the interplay between the lattice and electronic effects is still elusive. Specifically, the weakly absorbing tail states and dual em ...

Springer2019