Parametrization of an anharmonic Kirkwood-Keating potential for Alx Ga1-x As alloys

Eunji Sim, Joost Beckers, Simon De Leeuw, Michael Thorpe, Mark A Ratner

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

We introduce a simple semiempirical anharmonic Kirkwood-Keating potential to model Ax B1-x C -type semiconductors. The potential consists of the Morse strain energy and Coulomb interaction terms. The optical constants of pure components, AB and BC, were employed to fit the potential parameters such as bond-stretching and -bending force constants, dimensionless anharmonicity parameter, and charges. We applied the potential to finite temperature molecular-dynamics simulations on Alx Ga1-x As for which there is no lattice mismatch. The results were compared with experimental data and those of harmonic Kirkwood-Keating model and of equation-of-motion molecular-dynamics technique. Since the Morse strain potential effectively describes finite temperature damping, we have been able to numerically reproduce experimentally obtained optical properties such as dielectric functions and reflectance. This potential model can be readily generalized for strained alloys.

Original languageEnglish
Article number174702
JournalJournal of Chemical Physics
Volume122
Issue number17
DOIs
Publication statusPublished - May 2005

    Fingerprint

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Cite this