Graduation Semester and Year

2005

Language

English

Document Type

Thesis

Degree Name

Master of Science in Physics

Department

Physics

First Advisor

Asok Ray

Abstract

The local density approximation to density functional theory (LDA-DFT) has been used to study the different possible relaxations and reconstructions of In-rich InSb (100) surface. Various electronic and geometric structure properties such as, bond lengths, cohesive energies, band gaps and density of states of the ideal (1x1) surface and the (2x1), (4x2) and c(8x2) reconstructed InSb surfaces are reported. Adsorptions of lithium atom as well as other halogen atoms such as chlorine, bromine and iodine on the (1x1), (2x1), (4x2) and c (8x2) InSb surfaces in the different symmetric sites, such as, top, bridge, hollow, cave, trough and also interstitial cage site have been investigated. Details of energetics of the chemisorption process, such as chemisorption energies, and also the adatom separation distances, charge distributions, energy band gaps and density of states are discussed. The changes in the InSb surfaces due to these different atomic adsorptions are analyzed. In the final phase of this study, we address the question of whether the molecular adsorption of iodine on the InSb surface is feasible. The results of molecular as well as dissociative adsorptions are reported and it was found that dissociation is favored in many of the approaches in energetics point of view. The changes in the atomic charge distributions of the InSb surface due to the I2 adsorption, both molecularly as well as dissociatively are investigated. The variations in the HOMO-LUMO gaps when the I2 molecule is adsorbed are reported with the DOS plots illustrating these changes.

Disciplines

Physical Sciences and Mathematics | Physics

Comments

Degree granted by The University of Texas at Arlington

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