A. Pecchia

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We investigate the influence of molecular vibrations on the tunneling of electrons through an octane−thiolate sandwiched between two gold contacts. The coherent and incoherent tunneling currents are computed using the non-equilibrium Green's functions formalism. Both the system Hamiltonian and the electron−phonon interaction are obtained from(More)
Cross-conjugated molecules are known to exhibit destructive quantum interference, a property that has recently received considerable attention in single-molecule electronics. Destructive quantum interference can be understood as an antiresonance in the elastic transmission near the Fermi energy and leading to suppressed levels of elastic current. In most(More)
In this work we present a multiscale method to model self-heating effects in nanostructured devices. While the heating is modeled within the drift-diffusion approximation, the heat dissipation is computed by means of a concurrent coupling between a Phonon Boltzmann Transport Equation (PBTE) based method and the Fourier model. We develop the way to connect(More)
Due to the downscaling of semiconductor device dimensions and the emergence of new devices based on nanostructures, CNTs and molecules, the classical device simulation approach based on semi-classical transport theories needs to be extended towards a quantum mechanical description. We present a simulation environment designed for multiscale and multiphysics(More)
PACS. 73.63.-b – Electronic transport in nanoscale materials and structures. PACS. 73.63.Fg – Nanotubes. PACS. 63.22.+m – Phonons or vibrational states in low-dimensional structures and nanoscale materials. Abstract. – We study the influence of structural lattice fluctuations on the elastic electron transport in single-wall carbon nanotubes within a(More)
This paper show a novel implementation of the GW correction applied to DFTB method and show its applications to molecular systems sandwiched in-between electrodes to obtain a first-principle correction of the electron-electron interaction energy. The resulting self-energy is used to correct the system GF and to obtain a correction of the tunneling current,(More)
In this work we present a theoretical study of the effect of random alloy fluctuations in a InGaN inclusion embedded in a GaN nanowire (NW) LED on the electronic and optoelectronic properties. The calculations are based on an empirical tight-binding (ETB) model, while strain is calculated with a valence force field (VFF) method. Energy gaps distributions(More)
Different numerical simulations of quantum-dot heterostructures derived from experimental results are presented. We extrapolated three-dimensional dot models directly by atomic force microscopy and high-resolution transmission electron microscopy results, and we present electromechanical, continuum k⃗ · p⃗, atomistic Tight Binding and(More)
In this work we present the effect of compositional fluctuations in InGaN/GaN quantum wells (QWs) on their spontaneous emission properties. We show that random alloy fluctuations lead to fluctuations of both the optical matrix elements and the emission energy and that the two quantities are correlated. A qualitatively different behaviour between flat band(More)