Publications related to Interstitial defect

Identification and thermal healing of focused ion beam-induced defects in GaN using off-axis electron holography

Nicolas Grandjean, Jean-François Carlin, Raphaël Butté, Yi Wang

Thermal healing of focused ion beam-implanted defects in GaN is investigated by off-axis electron holography in TEM. The data reveal that healing starts at temperatures as low as about 250 degrees C. The healing processes result in an irreversible transiti ...

Iop Publishing Ltd2024

Atomic-scale Characterization of Strain and Gate effects on Two-dimensional Materials by Scanning Tunneling Microscopy

Jz -Yuan Juo

Strain is an inevitable phenomenon in two-dimensional (2D) material, regardless of whether the film is suspended or supported. Moreover, strain is known to alter the physical and chemical properties, such as the band gap, charge carrier effective masses, d ...

EPFL2023

Stoichiometry modulates the optoelectronic functionality of Zinc Phosphide (Zn3-xP2+x)

Anna Fontcuberta i Morral, Elias Zsolt Stutz, Santhanu Panikar Ramanandan, Mischa Samuel Flór, Jean-Baptiste Leran, Diego Armando Sandoval Salaiza, Mahdi Zamani, Simon Robert Escobar Steinvall, Rajrupa Paul, Mirjana Dimitrievska, Maria Chiara Spadaro

Predictive synthesis–structure–property relationships are at the core of materials design for novel applications. In this regard, correlations between the compositional stoichiometry variations and functional properties are essential for enhancing the perf ...

2022

Nanoscale Growth Initiation as a Pathway to Improve the Earth-Abundant Absorber Zinc Phosphide

Anna Fontcuberta i Morral, Elias Zsolt Stutz, Jean-Baptiste Leran, Mahdi Zamani, Simon Robert Escobar Steinvall, Rajrupa Paul, Mirjana Dimitrievska

Growth approaches that limit the interface area between layers to nanoscale regions are emerging as a promising pathway to limit the interface defect formation due to mismatching lattice parameters or thermal expansion coefficient. Interfacial defect mitig ...

AMER CHEMICAL SOC2022

Effect of ZnO on the reactivity of cementitious systems

Andrea Eloisa Teixeira Pita

One of the biggest driving forces in cement research today is the mitigation of the CO2 emissions caused by its production. A potential solution to reduce the environmental impact is to replace cement with supplementary cementitious materials (SCMs). This ...

EPFL2022

In Operando, Photovoltaic, and Microscopic Evaluation of Recombination Centers in Halide Perovskite-Based Solar Cells

Ulf Anders Hagfeldt, Henry Snaith, Silver Hamill Turren Cruz

The origin of the low densities of electrically active defects in Pb halide perovskite (HaP), a crucial factor for their use in photovoltaics, light emission, and radiation detection, remains a matter of discussion, in part because of the difficulty in det ...

AMER CHEMICAL SOC2022

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

Defects in III-N LEDs: experimental identification and impact on electro-optical characteristics

Nicolas Grandjean, Jean-François Carlin, Mauro Mosca, Camille Haller

III-N light-emitting-diodes (LEDs) are subject of intense investigations, thanks to their high efficiency and great reliability. The quality of the semiconductor material has a significant impact on the electro-optical performance of LEDs: for this reason, ...

SPIE-INT SOC OPTICAL ENGINEERING2022

Wafer-scale MoS2 with water-vapor assisted showerhead MOCVD

Aleksandra Radenovic, Andras Kis, Mukesh Kumar Tripathi, Mukeshchand Thakur, Michal Daniel Macha, Yanfei Zhao, Hyungoo Ji, Jing Zhang

Among numerous thin film synthesis methods, metalorganic chemical vapor deposition performed in a showerhead reactor is the most promising one for broad use in scalable and commercially adaptable two-dimensional material synthesis processes. Adapting the m ...

ROYAL SOC CHEMISTRY2022

Imaging Nonradiative Point Defects Buried in Quantum Wells Using Cathodoluminescence

Nicolas Grandjean, Jean-François Carlin, Raphaël Butté, Duncan Thomas Lindsay Alexander, Wei Liu, Wei Liu, Thomas Fjord Kjaersgaard Weatherley

Crystallographic point defects (PDs) can dramatically decrease the efficiency of optoelectronic semiconductor devices, many of which are based on quantum well (QW) heterostructures. However, spatially resolving individual nonradiative PDs buried in such QW ...

AMER CHEMICAL SOC2021

Spectroscopic view of ultrafast charge carrier dynamics in single- and bilayer transition metal dichalcogenide semiconductors

Jens Christian Johannsen

The quasiparticle spectra of atomically thin semiconducting transition metal dichalcogenides (TMDCs) and their response to an ultrafast optical excitation critically depend on interactions with the underlying substrate. Here, we present a comparative time- ...

ELSEVIER2021

Nanopillars Enabling III-V Integration on Si (100) and (111)

Lucas Güniat

The majority of current semiconductor technologies are built on Si (100), such as the CMOS technology, or conventional solar cell devices. III-V semiconductors offer great perspectives given their high carrier mobility and direct band gap. However their in ...

EPFL2021

Crystallization kinetics of atomic crystals revealed by a single-shot and single-particle X-ray diffraction experiment

Christoph Bostedt, Alessandro Colombo, Giorgio Rossi

Crystallization is a fundamental natural phenomenon and the ubiquitous physical process in materials science for the design of new materials. So far, experimental observations of the structural dynamics in crystallization have been mostly restricted to slo ...

National Academy of Sciences2021

Structural and Dynamical Properties of Potassium Dodecahydro-monocarba-closo-dodecaborate: KCB11H12

Mirjana Dimitrievska, Wei Zhou

MCB11H12 (M: Li, Na) dodecahydro-monocarba-closo-dodecaborate salt compounds are known to have stellar superionic Li+ and Na+ conductivities in their high-temperature disordered phases, making them potentially appealing electrolytes in all-solid-state batt ...

AMER CHEMICAL SOC2020

Theoretical maximum photogeneration efficiency and performance characterization of InxGa1-xN/Si tandem water-splitting photoelectrodes

Sophia Haussener, Yannick Kenneth Gaudy

InxGa1-xN is a promising material for flexible and efficient water-splitting photoelectrodes since the bandgap is tunable by modifying the indium content. We investigate the potential of an InxGa1-xN/Si tandem used as a water-splitting photoelectrode. We p ...

2020

Impact of defects on Auger recombination in c-plane InGaN/GaN single quantum well in the efficiency droop regime

Nicolas Grandjean, Jean-François Carlin, Raphaël Butté, Yixing Chen, Gwénolé Jean Jacopin, Wei Liu, Camille Haller, Thomas Fjord Kjaersgaard Weatherley

We study the impact of non-radiative defects on Auger recombination in c-plane InGaN/GaN single quantum wells (SQWs) in the efficiency droop regime using high injection time-resolved photoluminescence. The defect density in the SQW is controlled by tuning ...

AMER INST PHYSICS2020

Defect Formation Energies of Interstitial C, Si, and Ge Impurities in beta-Ga2O3

Alfredo Pasquarello, Assil Bouzid

Formation energies of C, Si, and Ge defects in beta-Ga2O3 are studied through hybrid functional calculations. The interstitial defects of these elements generally occur at higher energies than their substitutional counterparts, but are more stable at low F ...

WILEY-V C H VERLAG GMBH2019

Deposition of impurity metals during campaigns with the JET ITER-like Wall

Olivier Sauter, Ambrogio Fasoli, Basil Duval, Stefano Coda, Jonathan Graves, Yves Martin, Duccio Testa, Patrick Blanchard, Henri Weisen, Alessandro Pau, Federico Nespoli, Cristian Sommariva, David Pfefferlé, Richard Pitts, Jonathan Marc Philippe Faustin, Yann Camenen, Hamish William Patten, Jan Horacek, Samuel Lanthaler, Javier García Hernández, Marco Wischmeier, Nicola Vianello, Mikhail Maslov, Yao Zhou, Davide Galassi, Antonio José Pereira de Figueiredo, Liang Yao, Dalziel Joseph Wilson, Bernhard Sieglin, Otto Asunta

Post mortem analysis shows that mid and high atomic number metallic impurities are present in deposits on JET plasma facing components with the highest amount of Ni and W, and therefore the largest sink, being found at the top of the inner divertor. Source ...

Elsevier2019

Adjustable potential probes for band-gap predictions of extended systems through nonempirical hybrid functionals

Alfredo Pasquarello, Igor Reshetnyak, Thomas Bischoff

We describe a nonempirical procedure for achieving accurate band gaps of extended systems through the insertion of suitably defined potential probes. By enforcing Koopmans' condition on the resulting localized electronic states, we determine the optimal fr ...

2019

Self-consistent site-dependent DFT plus U study of stoichiometric and defective SrMnO3

Nicola Marzari, Iurii Timrov, Ulrich Aschauer, Matteo Cococcioni

We propose a self-consistent site-dependent Hubbard U approach for density functional theory (DFT)+U calculations of defects in complex transition metal oxides, using Hubbard parameters computed via linear response theory. The formation of a defect locally ...

AMER PHYSICAL SOC2019