1,721,181 research outputs found
Improving the accuracy of the Schroedinger-Poisson solution in CNWs and CNTs
No full textThe Schroedinger equation, or the coupled Schroedinger and Poisson equations, are transformed into an integral equation. Back-substituting from the original equations allows one to approximate the numerical corrections to any order without the need of calculating derivatives of the unknown function of order larger than one. Typical applications are in the numerical analysis of quantum transport in nanowires and nanotubes in the ballistic regime
The Numerov process over a non-uniform grid
Full text linkThe Numerov process is a solution method applicable to some classes of differential equations, that provides an error term of the fifth order in the grid size with a computational cost comparable to that of the finite-difference scheme. In the original formulation of the method, a uniform grid size is required; the paper shows a procedure for extending its applicability to a non-uniform grid in one dimension. The effectiveness of the procedure is tested on a model problem, and comparisons with other methods are carried out. Finally, it is shown how to extend the applicability of the method to a larger class of equations; among these, the mathematical model of semiconductor devices is important in view of its applications to the integrated-circuit technology
Boundary-Fitted Coordinate Generation for Device Analysis on Composite and Complicated Geometries
No full textMonte Carlo analysis of anisotropy in the transport relaxation times for the hydrodynamic model
No full textThis paper investigates the anisotropy properties of the relaxation times used in the hydrodynamic model. To this purpose a calculation of the collision term of the Boltzmann Transport Equation is performed by means of a Monte Carlo code accounting for the proper band structure and scattering features. Numerical results for electrons in silicon are shown at 77 and 300 K for E parallel to [100] and E parallel to [111]
A Physically-Based Analytical Model for a-Si Devices Including Drift and Diffusion Currents
No full textParticle and energy fluxes in semiconductors: Full-band hydrodynamic equations and the thermodynamic limit
No full textThe hydrodynamic model for semiconductors includes equations of continuity for the carrier number, average energy, average velocity, and average energy flux. The last two equations can be recast as generalized drift-diffusion expressions, which are formally similar to those of the particle and energy fluxes provided by classical thermodynamics based upon entropy production. The derivation of the hydrodynamic model is reexamined, and the entropy principle is derived from the definition of fermion entropy. It is shown that the thermodynamic expressions are included as a limiting case of the hydrodynamic expressions and, in particular, that the hydrodynamic definitions of the momentum-relaxation time and energy-flux relaxation time provide the correct thermodynamic limit by fulfilling the Onsager relation. [S0163-1829(99)02840-4]
Hot-carrier thermal conductivity for hydrodynamic analyses
No full textA theoretical and computational analysis of the anisotropy properties of the hot-carrier thermal conductivity in semiconductors is presented
An Efficient Numerical Method to Solve the Time-Dependent Semiconductor Equations Including Trapped Charge
No full text- …
