Carbon nanotube (CNT) based transistors have been studied in recent years as potential alternatives to CMOS devices because of their capability of near ballistic transport. In this work the non-equilibrium Green’s function (NEGF) formalism is used to perform a comprehensive study of CNT based transistors. The effect of inelastic phonon scattering on the gate-delay time of CNT based transistors ...

We report the results of multi-scale modeling of ultra-narrow graphene nanoribbons (GNRs) that combines atomistic non-equilibrium Green’s function (NEGF) approach with semiclassical mobility modeling. The variability of the transport gap and carrier mobility caused by random edge defects is analyzed. We find that the variability increases as the GNR width is downscaled and that even the minimum...

We have investigated transport properties of higher acenes pentacene and hexacene and compared it with the transport properties of their BN analogues. Charge hopping from one structure to another was investigated through calculations of reorganization energies based on DFT and Marcus semiempiric approach, while the investigation of charge transport along the investigated structures was based on...

Transport properties of sub-5 nm-wide graphene nanoribbons (GNRs) are investigated by using atomistic non-equilibrium Green’s function (NEGF) simulations and semiclassical mobility simulations of large ensembles of randomly generated nanoribbons. Realistic GNRs with dimensions targeting the 12 nm CMOS node are investigated by accounting for edge defects, vacancies and potential fluctuations. Ef...

Confined structures presumably offer enhanced performance of thermoelectric devices. 1) Interfaces and boundaries create scattering sites for phonons, which reduces the thermal conductivity. 2) Reduced dimensionality increases the local density of states near the Fermi level, which increases the Seebeck coefficient. From these two phenomena, the net effect should be an increase in ZT, the perfo...

Graphene nanoribbons (GNRs) are the most important emerging structures for nanoelectronic and sensor applications. GNRs with perfect lattices have been extensively studied, but fabricated contain lattice defects effect of which on their electronic properties has not studied enough. In this paper, we apply Non-Equilibrium Green's function (NEGF) method combined tight-binding Hamiltonians to inve...

We assess the viability of topological semimetals for application in advanced interconnect technology, where conductor size is on order a few nanometers and grain boundaries are expected to be prevalent. investigate electron transport properties boundary scattering thin films CoSi CoGe using first-principles calculations combined with Non-Equilibrium Green's Function (NEGF) technique. Unlike co...

The Seebeck coefficient is an important quantity in determining the thermoelectric efficiency of a material. Phosphorene two-dimensional material with puckered structure, which makes its properties anisotropic. In this work, phosphorene nanodisk (PDisk) radius 3.1 nm connected to two zigzag nanoribbons studied, numerically, by tight-binding and non-equilibrium Green’s function (NEGF) methods pr...

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...

A three-dimensional full band simulator for nanowire field-effect transistors (FETs) is presented in this thesis. At the nanometer scale the classical drift-diffusion transport theory reaches its limits; quantum transport (QT) phenomena govern the motion of electrons and holes. The development of a QT simulator requires the assembly of several physical models and the choice of appropriate simpl...