Publications de Giacomo Francesco Leonardo Miceli

Nonempirical dielectric-dependent hybrid functional with range separation for semiconductors and insulators

Alfredo Pasquarello, Wei Chen, Giacomo Francesco Leonardo Miceli

2018

Nonempirical hybrid functionals for band gaps and polaronic distortions in solids

Alfredo Pasquarello, Wei Chen, Giacomo Francesco Leonardo Miceli, Igor Reshetnyak

2018

Electronic Levels of Excess Electrons in Liquid Water

Alfredo Pasquarello, Giacomo Francesco Leonardo Miceli, Francesco Ambrosio

We provide a consistent description of the electronic levels associated with localized and delocalized excess electrons in liquid water by combining hybrid-functional molecular dynamics simulations with a grand canonical formulation of solutes in aqueous s ...

Amer Chemical Soc2017

Oxygen DX center in In0.17Al0.83N: Nonradiative recombination and persistent photoconductivity

Alfredo Pasquarello, Rocco Meli, Giacomo Francesco Leonardo Miceli

Using a hybrid density-functional scheme, we address the O impurity substitutional to N (O-N) in In0.17Al0.83N. Our modelling supports In clustering to account for the strong band-gap bowing observed in InxAl1-xN alloys. To study the ON defect in In0.17Al0 ...

American Institute of Physics2017

Migration of Mg and other interstitial metal dopants in GaN

Alfredo Pasquarello, Giacomo Francesco Leonardo Miceli

The minimumenergy paths for the migration of interstitialMgin wurtziteGaNare studiedthroughdensityfunctional calculations. The study also comprises Li, Na, and Be dopants to examine the dependence on size and charge of the dopant species. In all cases cons ...

Wiley-Blackwell2017

Liquid Water through Density-Functional Molecular Dynamics: Plane-Wave vs Atomic-Orbital Basis Sets

Alfredo Pasquarello, Giacomo Francesco Leonardo Miceli

We determine and compare structural, dynamical, and electronic properties of liquid water at near ambient conditions through density-functional molecular dynamics simulations, when using either plane-wave or atomic-orbital basis sets. In both frameworks, t ...

Amer Chemical Soc2016

Self-compensation due to point defects in Mg-doped GaN

Alfredo Pasquarello, Giacomo Francesco Leonardo Miceli

Using hybrid density functional theory, we address point defects susceptible to cause charge compensation upon Mg doping of GaN. We determine the free energy of formation of the nitrogen vacancy and of several Mg-related defects. The entropic contribution ...

Amer Physical Soc2016

Structural, Dynamical, and Electronic Properties of Liquid Water: A Hybrid Functional Study

Alfredo Pasquarello, Giacomo Francesco Leonardo Miceli, Francesco Ambrosio

We study structural, dynamical, and electronic properties of liquid water through ab initio molecular dynamics (MD) simulations based on a hybrid functional which includes nonlocal van der Waals (vdW) interactions. The water dimer, the water hexamer, and t ...

Amer Chemical Soc2016

Ab initio Electronic Structure of Liquid Water

Alfredo Pasquarello, Wei Chen, Giacomo Francesco Leonardo Miceli, Francesco Ambrosio

Self-consistent GW calculations with efficient vertex corrections are employed to determine the electronic structure of liquid water. Nuclear quantum effects are taken into account through ab initio path-integral molecular dynamics simulations. We reveal a ...

American Physical Society2016

Band alignment and chemical bonding at the GaAs/Al2O3 interface: A hybrid functional study

Alfredo Pasquarello, Davide Colleoni, Giacomo Francesco Leonardo Miceli

The band alignment at the interface between GaAs and amorphous Al2O3 is studied through the use of hybrid functionals. For the oxide component, a disordered model is generated through density-functional molecular dynamics. The achieved structure shows good ...

2015

Fermi-level pinning through defects at GaAs/oxide interfaces: A density functional study

Alfredo Pasquarello, Davide Colleoni, Giacomo Francesco Leonardo Miceli

Using density functional calculations, we study a set of candidate defects for Fermi-level pinning at GaAs/oxide interfaces. The set of considered defects comprises both bulklike and interfacial defects, including As antisites, Ga and As dangling bonds, th ...

American Physical Society2015

Redox levels in aqueous solution: Effect of van der Waals interactions and hybrid functionals

Alfredo Pasquarello, Giacomo Francesco Leonardo Miceli, Francesco Ambrosio

We investigate redox levels in aqueous solution using a combination of ab initio molecular dynamics (MD) simulations and thermodynamic integration methods. The molecular dynamics are performed with both the semilocal Perdew-Burke-Ernzerhof functional and a ...

2015

Energetics of native point defects in GaN: A density-functional study

Alfredo Pasquarello, Giacomo Francesco Leonardo Miceli

We study the formation energies of native point defects in GaN through density-functional theory. In our first-principles scheme, the band edges are positioned in accord with hybrid density functional calculations, thus yielding a band-gap in agreement wit ...

Elsevier2015

Arsenic related defect states resonant with the semiconductor conduction band at the In0.53Ga0.47As/oxide interface: A density functional study

Alfredo Pasquarello, Davide Colleoni, Giacomo Francesco Leonardo Miceli

An arsenic related defect at the In0.53Ga0.47As/oxide interface is studied through density functional theory. This defect corresponds to an As-As timer which transforms into two doubly occupied As dangling bonds upon capture of two electrons. The defect ch ...

Elsevier2015

Isobaric first-principles molecular dynamics of liquid water with nonlocal van der Waals interactions

Alfredo Pasquarello, Giacomo Francesco Leonardo Miceli

We investigate the structural properties of liquid water at near ambient conditions using first-principles molecular dynamics simulations based on a semilocal density functional augmented with nonlocal van der Waals interactions. The adopted scheme offers ...

American Institute of Physics2015

Origin of Fermi-level pinning at GaAs surfaces and interfaces

Alfredo Pasquarello, Davide Colleoni, Giacomo Francesco Leonardo Miceli

Through first-principles simulation methods, we assign the origin of Fermi-level pinning at GaAs surfaces and interfaces to the bistability between the As-As dimer and two As dangling bonds, which transform into each other upon charge trapping. This defect ...

Institute of Physics2014

Defect levels at GaAs/Al2O3 interfaces: As-As dimer vs. Ga dangling bond

Alfredo Pasquarello, Giacomo Francesco Leonardo Miceli

Charge transition levels of the As-As dimer and the Ga dangling bond at GaAs/Al2O3 interfaces are determined through density-functional calculations. The same parent interface model structure is used as a starting point for creating both defects providing ...

Elsevier2014

Accurate determination of charge transition levels of the As-As dimer defect at GaAs/oxide interfaces through hybrid functionals

Alfredo Pasquarello, Giacomo Francesco Leonardo Miceli

The energy levels of the As-As dimer defect at GaAs/oxide interfaces are accurately determined within a hybrid functional scheme and aligned with respect to the GaAs band gap. An As-As dimer is constructed at a model interface between GaAs and kappa-Al2O3, ...

2013

First principles study of As 2p core-level shifts at GaAs/Al2O3 interfaces

Alfredo Pasquarello, Giacomo Francesco Leonardo Miceli

Arsenic 2p core-level shifts at GaAs/Al2O3 interfaces are determined with respect to bulk GaAs through density functional calculations. Atomistic interface models are constructed in which As atoms are found in various chemical environments. Both Ga-termina ...

American Institute of Physics2013

Fast Crystallization of the Phase Change Compound GeTe by Large-Scale Molecular Dynamics Simulations

Giacomo Francesco Leonardo Miceli, Federico Giberti

Phase change materials are of great interest as active layers in rewritable optical disks and novel electronic nonvolatile memories. These applications rest on a fast and reversible transformation between the amorphous and crystalline phases upon heating, ...

Amer Chemical Soc2013