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Solar Cells Operation and Modeling

19 Jul 2010 | Contributor(s): Dragica Vasileska, Gerhard Klimeck

This set of slides decribes the basic principles of operation of various generations on solar cells with emphasis to single crystalline solar cells. Next, semiconductor equations that describe the operation of a solar cell under simplified conditions is given. Finally, modeling of single...

Atomistic Simulations of Reliability

06 Jul 2010 | Contributor(s): Dragica Vasileska

Discrete impurity effects in terms of their statistical variations in number and position in the inversion and depletion region of a MOSFET, as the gate length is aggressively scaled, have recently been researched as a major cause of reliability degradation observed in intra-die and die-to-die...

Rode's Method: Theory and Implementation

This set of teaching materials provides theoretical description of the Rode's method for the low field mobility calculation that is accompanied with a MATLAB code for the low field mobility calculation for GaAs material at different temperatures and different doping concentrations. Note that the...

Negative Differential Resistivity Exercise

28 Jun 2010 | Contributor(s): Gerhard Klimeck, Parijat Sengupta, Dragica Vasileska

In certain semiconductors such as GaAs and InP the average velocity as a function of field strength displays a maximum followed by a regime of decreasing velocity. Hilsum, Ridley, and Watkins postulated that peculiarities in the band structure of semiconductors would lead to the above...

Crystal Viewer Lab Exercise

A central problem in the investigation of material properties involves the examination of the underlying blocks that aggregate to form macroscopic bodies. These underlying blocs own a definite arrangement that is repeated in three dimensions to give the crystal structure. We will try to explore...

Band Structure Lab Exercise

Investigations of the electron energy spectra of solids form one of the most active fields of research. Knowledge of band theory is essential for application to specific problems such as Gunn diodes, tunnel diodes, photo-detectors etc. There are several standard methods to compute the band...

Analytical and Numerical Solution of the Double Barrier Problem

Tunneling is fully quantum-mechanical effect that does not have classical analog. Tunneling has revolutionized surface science by its utilization in scanning tunneling microscopes. In some device applications tunneling is required for the operation of the device (Resonant tunneling diodes,...

Exercise for MOSFET Lab: Device Scaling

28 Jun 2010 | Contributor(s): Dragica Vasileska, Gerhard Klimeck

This exercise explores device scaling and how well devices are designed.

Periodic Potentials Exercise

16 Jun 2010 | Contributor(s): Gerhard Klimeck, Parijat Sengupta, Dragica Vasileska

In this exercise, various calculations of the electronic band structure of a one-dimensional crystal are performed with the Kronig-Penney (KP) model. This model has an analytical solution and therefore allows for simple calculations. More realistic models always require extensive numeric...

Quantum Tunneling Exercise

Exercise BackgroundTunneling is fully quantum-mechanical effect that does not have classical analog. Tunneling has revolutionized surface science by its utilization in scanning tunneling microscopes. In some device applications tunneling is required for the operation of the device (Resonant...

Quantum Bound States Exercise

Exercise BackgroundQuantum-mechanical systems (structures, devices) can be separated into open systems and closed systems. Open systems are characterized with propagating or current carrying states. Closed (or bound) systems are described with localized wave-functions. One such system is a...

Crystal Viewer Tool Verification (V 2.3.4)

15 Jun 2010 | Contributor(s): Dragica Vasileska, Gerhard Klimeck

This text verifies the Crystal Viewer Tool by comparing the amount of dangling bonds at the silicon surface for [100], [110] and [111] crystal orientation. The crystal viewer results are in agreement with experimental findings.

Crystal Structures - Packing Efficiency Exercise

Consider the most efficient way of packing together equal-sized spheres and stacking close-packed atomic planes in three dimensions. For example, if plane A lies beneath plane B, there are two possible ways of placing an additional atom on top of layer B. If an additional layer was placed...

Physical and Mathematical Description of the Operation of Photodetectors

08 Jun 2010 | Teaching Materials | Contributor(s): Dragica Vasileska

This set of slides describes physical and mathematical description of the operation of photodetectors including important figures of merit.

Solve a Challenge for a PN Diode

08 Jun 2010 | Teaching Materials | Contributor(s): Dragica Vasileska, Gerhard Klimeck

This is SOLVE A CHALLENGE PROBLEM for pn-diodes.

Verification of the Validity of the PN Junction Tool

These simulations and comparisons with the depletion charge approximation prove the validity of the PN Junction tool.

Crystal Directions and Miller Indices

08 Jun 2010 | Teaching Materials | Contributor(s): David K. Ferry, Dragica Vasileska, Gerhard Klimeck

Miller indices are a notation system in crystallography for planes and directions in crystal lattices. In particular, a family of lattice planes is determined by three integers, l, m, and n, the Miller indices. They are written (lmn) and denote planes orthogonal to a direction (l,m,n) in the...

Crystal Structures

In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. A crystal structure is composed of a basis, a set of atoms arranged in a particular way, and a lattice. The basis is located upon the points of a lattice spanned by lattice vectors, which is an...

Multigrid Tutorial

This set of slides describe the idea behind the multigrid method and its implementation.

Conjugate Gradient Tutorial

This is an extensive tutorial on the description and implementation of the basic conjugate gradient method and its variants.

Poisson Equation Solvers - General Considerations

We describe the need for numerical modeling, the finite difference method, the conversion from continuous set to set of matrix equations, types of solvers for solving sparse matrix equations of the form Ax=b that result, for example, from the finite difference discretization of the Poisson Equation.

Poisson Equation Solvers

There are two general schemes for solving linear systems: Direct Elimination Methods, and Iterative Methods.All the direct methods are, in some sense, based on the standard Gauss Elimination technique, which systematically applies row operations to transform the original system of equations into...

Tight-Binding Band Structure Calculation Method

This set of slides describes on simple example of a 1D lattice, the basic idea behind the Tight-Binding Method for band structure calculation.

Solar Cells Numerical Solution

This is an MS Thesis of Balaji Padmanabhan, a student of Prof. Vasileska. It describes numerical solution details for the 3D drift-diffusion equations as applied to modeling 1D-3D solar cells.

PCPBT Manual

This is a manual for the Piece-Wise Constant Potential Barrier Tool.