The use of ensemble Monte Carlo (EMC) methods for the simulation transport in semiconductor devices has become extensive over past few decades. This method allows utilizing particles while addressing full physics within device, leaving computational difficulties to computer. More recently, study quantum mechanical effects devices, which also strongly affect carrier itself, have important. While...

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...

Non-equilibrium Green’s function formalism (NEGF) by employing timedependent (TD) perturbation theory is used to solve the electronic equations of motion of model systems under potential biasing conditions. The time propagation is performed in the full frequency domain of the two time variables representation. We analyze transient aspects of the resulting conductance under effects of applied di...

The effects of layer thickness and periodicity on thermoelectric properties of Si/Ge superlattice materials are studied through a non-equilibrium Green’s function (NEGF) computational approach. Results show an independence of Seebeck coefficient for increasing the number of superlattice periods. Additionally, a critical layer thickness is obtainable to achieve a favorable transmission spectrum ...

Using the non-equilibrium Green's function (NEGF) formalism within the sequential regime, we studied ultrahigh spin thermopower and pure spin current in single-molecule magnet(SMM), which is attached to nonmagnetic metal wires with spin bias and angle (θ) between the easy axis of SMM and the spin orientation in the electrodes. A pure spin current can be generated by tuning the gate voltage and ...

In this thesis electronic transport through nanoscale devices is modeled by means of quantum physics. Moving from ballistic transport towards a detailed description of electron-phonon scattering, the used formalism changes from wave functions to the non-equilibrium Green’s functions (NEGF). The simulation framework consists of the quantum mechnical simulator SIMNAD, which was developed at the I...

We propose a scheme for calculation of linear optical response of current-carrying molecular junctions for the case when electronic tunneling through the junction is much faster than characteristic time of external laser field. We discuss relationships between nonequilibrium Green's function (NEGF) and time-dependent density functional theory (TDDFT) approaches and derive expressions for optica...

The superfluid properties of disordered double-layer graphene systems are investigated using the non-equilibrium Green’s function (NEGF) formalism. The complexity of such a structure makes it imperative to study the effects of lattice vacancies which will inevitably arise during fabrication. Room-temperature performance characteristics for both ideal and disordered bilayer graphene systems are ...

The electronic behavior of metallic carbon nanotubes under the influence of externally applied electric fields is investigated using the Non-Equilibrium Green’s function method self consistently coupled with three-dimensional (3D) electrostatics. A nearest neighbor tight binding model based on a single pz orbital for constructing the device Hamiltonian is used. The 3D Poisson equation is solved...

This paper aims to investigate the spin dependent transport properties in hybrid nanoribbons, using non equilibrium Greens function method. The effects of temperature gradient between left and right leads, ferromagnetic exchange field, local external electric fields are also included. results show that up down currents produced flow opposite directions with almost equal magnitudes. evidently sh...