Ab-initio Calculation method of electronic structure of InXGa1-XAs nanocrystal
Other Title(s)
التركيب الإلكتروني لبلورة (InxGa1-xAs) النانوية بطريقة الحسابات الأساسية (Ab-inito)
Dissertant
Thesis advisor
University
University of Baghdad
Faculty
College of Science
Department
Department of Physics
University Country
Iraq
Degree
Ph.D.
Degree Date
2013
English Abstract
Ab-initio density functional theory (DFT) at the generalized gradient approximation (GGA) level coupled with large unit cell (LUC) method with STO-3G basis sets have been used to determine and investigate the electronic properties of Indium Gallium Arsenide (InxGa1-xAs) nanocrystals with different core part size (8, 16, 54, 64) and concentrations (x=0.
, 0.25, 0.50 and 1.0), using 3D periodic boundary condition (PBC).
Two kinds of cells were investigated; Bravais cubic cell multiples and primitive parallelpiped cell multiples.
Gaussian 03 programs were prepared to perform computation using Fortran as programming language.
The atoms positions and their properties for above crystals have been used as input data.
The final modified LUC-Ab-initio-DFT equations are embodied in the computer and solved by iterative self consistent field (SCF) methods.
The electronic properties such as ionicity, cohesive energy and density of states (which reaches definite values) have been calculated, in addition to that the energy gap, conduction and valence band, electron affinity, ionization potential have been calculated taking into account the fluctuates in definitely depending on the shape.
The obtained results for zinc-blende III-V GaAs core part shows it has dimensions around (1.56-2.04) nm.
The values of energy gap in the The obtained results for zinc–blende III-V InAs core part shows, it has dimensions in the range (1.71-2.32) nm while the values of energy gap in the range of (2.41-2.57) eV corresponding to the lattice constant between XII (0.57-0.58) nm for different core size atoms (8, 16, 54, 64).
The size and alloy compound for InxGa1-xAs is varied so that it can be tuned to the required applications.
Zinc-blende InxGa1-xAs nanocrystals which show dimensions around (1.59-2.27) nm, while, the small values of energy gap in the range of (1.02-2.00) eV and increasing the ratio of In in the InxGa1-xAs may be attribute to the alloying composition.
While the total energy and cohesive energy are inversely is found to be proportional with the number of core for all concentrations (0, 0.25, 0.50, 0.75, 1.0).
Main Subjects
No. of Pages
101
Table of Contents
Table of contents.
Abstract.
Abstract in Arabic.
Chapter One : Introduction.
Chapter Two : Theoretical background.
Chapter Three : Results and discussion.
Chapter Four : Conclusions and future works.
References.
American Psychological Association (APA)
Bayraqdar, Akram Hashim Taha. (2013). Ab-initio Calculation method of electronic structure of InXGa1-XAs nanocrystal. (Doctoral dissertations Theses and Dissertations Master). University of Baghdad, Iraq
https://search.emarefa.net/detail/BIM-607665
Modern Language Association (MLA)
Bayraqdar, Akram Hashim Taha. Ab-initio Calculation method of electronic structure of InXGa1-XAs nanocrystal. (Doctoral dissertations Theses and Dissertations Master). University of Baghdad. (2013).
https://search.emarefa.net/detail/BIM-607665
American Medical Association (AMA)
Bayraqdar, Akram Hashim Taha. (2013). Ab-initio Calculation method of electronic structure of InXGa1-XAs nanocrystal. (Doctoral dissertations Theses and Dissertations Master). University of Baghdad, Iraq
https://search.emarefa.net/detail/BIM-607665
Language
English
Data Type
Arab Theses
Record ID
BIM-607665
