Semiconductor effective charges from tight-binding theory

Semiconductor effective charges from tight-binding theory.

We calculate the transverse effective charges of zinc-blende compound semiconductors using Harrison’s tight-binding model to describe the electronic structure. Our results, which are essentially exact within the model, are found to be in much better agreement with experiment than previous perturbation-theory estimates. Efforts to improve the results by using more sophisticated variants of the t...

Approximate bandstructures of semiconductor alloys from tight-binding supercell calculations

Alloys such as AlGaAs, InGaAs, and SiGe find widespread usage in nanoelectronic devices such as quantum dots and nanowires. For these devices, in which the carriers probe nanometre-scale local disorder, the commonly employed virtual crystal approximation (VCA) is inadequate. Although the VCA produces small-cell E(k) relations it fails to include local disorder. In contrast, random-alloy superce...

Effective-medium tight-binding model for silicon.

Tight-binding theory of molecules and solids

A general tight-binding analysis is described which differs from traditional methods in that 1) analytical forms are derived and utilized for obtaining the coupling parameters, and 2) the calculation of electronic-state energies is simplified sufficiently that they also can be obtained analytically. With these two features it becomes possible to write formulae for a wide range of bonding, diele...

An Effective-Medium Tight-Binding Model for Silicon

A new method for calculating the total energy of Si systems is presented. The method is based on the effective-medium theory concept of a reference system. Instead of calculating the energy of an atom in the system of interest a reference system is introduced where the local surroundings are similar. The energy of the reference system can be calculated selfconsistently once and for all while th...