This tutorial article presents a ‘bottom-up’ view of electrical resistance starting from something really small, like a molecule, and then discussing the issues that arise as we move to bigger conductors. Remarkably, no serious quantum mechanics is needed to understand electrical conduction through something really small, except for unusual things like the Kondo effect that are seen only for a ...

Self assembled quantum dots have shown a great promise as a leading candidate for infrared detection at room temperature. In this paper, a theoretical model of the absorption coefficient of quantum dot devices is presented. Both of bound to bound absorption and bound to continuum absorption are taken into consideration in this model. This model is based on the effective mass theory and the Non ...

A simple method that accurately captures the dynamics of metal− molecule−metal junctions under the influence of time-dependent driving forces is presented. In the method, the metallic contacts are modeled explicitly as a discrete set of levels that are dynamically broadened via an artificial damping term in the equations of motion. The approximations that underlie the method are revealed via a ...

Several new reduced-scale structures have been proposed to improve thermoelectric properties of materials. In particular, superlattice thin films and wires should decrease the thermal conductivity, due to increased phonon boundary scattering, while increasing the local electron density of states for improved thermopower. The net effect should be increased ZT, the performance metric for thermoel...

We study electronic conductance through single molecules by subjecting a molecular junction to a time dependent potential and propagating the electronic state in real time using time-dependent density functional theory (TDDFT). This is in contrast with the more common steady-state nonequilibrium Green’s function (NEGF) method. We start by examining quantum scale conductance methods in both the ...

An atomistic full-band quantum transport simulator has been developed to study threedimensional Si nanowire field-effect transistors (FETs) in the presence of electron-phonon scattering. The Non-equilibrium Green’s Function (NEGF) formalism is solved in a nearest-neighbor sp3d5s∗ tight-binding basis. The scattering self-energies are derived in the self-consistent Born approximation to inelastic...

Carrier transport in modern nanoelectronic devices involves physical scales which require quantum descriptions. Basic quantum mechanics describes systems determined by Hamiltonian state vectors |Ψ>, which provide the spatial and time dependences of the physical observables. A pure state density operator |Ψ><Ψ| as obtained by a single state vector contains the most complete information about the...

The understanding and modeling of heat transport across nanometer subnanometer gaps, where the distinction between thermal radiation conduction becomes blurred, remains an open question. In this work, we present a three-dimensional atomistic simulation framework by combining molecular dynamics (MD) phonon nonequilibrium Green's function (NEGF) methods. relaxed atomic configuration interaction f...

In this paper, we have carried out a numerical simulation of FinFETs. The model is based on 1D non-equilibrium Green’s function (NEGF) along the channel and 2-D Schrödinger equation in the confined cross section and provides insights into the performance of FinFETs with ultra small channel cross section. The simulation results of FinFETs show normal I-V characteristics with great potential in s...

We have included Shockley-Read-Hall (SRH) generation/recombination in Non-equilibrium Green’s function (NEGF) calculations via a multiphonon relaxation model. The model has been used to study how the presence of defects affects current–voltage characteristics GaAs p-i-n diodes, and an InGaAs tunnel diode. Regarding we show that SRH is responsible for ideality factors approaching theoretical val...