Zinc Sulphide Doped With Chromium. A Density Functional Theory Study

Inhaltsverzeichnis (Table of Contents)

• CHAPTER 01: INTRODUCTION
  • 1.1 Research Problem
  • 1.2 Research Plan
• CHAPTER 02: LITERATURE REVIEW
• CHAPTER 03: THEORETICAL BACKGROUND
  • 3.1 Energy Band Theory.
  • 3.2 Semiconductors and their Characteristics
  • 3.3 Direct/Indirect Band Gap Semiconductors---
  • 3.4 II-VI Compound Semiconductors--
  • 3.5 Zinc Sulphide
  • 3.6 Exchange Interaction
    • 3.6.1 Direct Exchange Interaction
    • 3.6.2 Indirect Exchange Interaction
      • 3.6.2.1 Double Exchange Interaction
  • 3.7 Jahn Teller Effect
  • 3.8 Techniques for Computational Study
  • 3.9 Density Functional Theory
    • 3.9.1 Many-Body Problems in Solids
    • 3.9.2 Hohenburg-Kohen Theorems
      • 3.9.2.1 First Hohenburg Kohen Theorem
      • 3.9.2.2 Second Hohenburg Kohen Theorem
    • 3.9.3 Kohan-Sham Equation
    • 3.9.4 Exchange Correlational Functional
    • 3.9.5 Local Density Approximation (LDA)
    • 3.9.6 Local Spin Density Approximation (LSDA)
    • 3.9.7 Generalized Gradient Approximation (GGA)
    • 3.9.8 LDA and GGA with Hubbard Correction
    • 3.9.9 Hybrid Functional
    • 3.9.10 Tran-Blah Modified Becke Johnson Potential (TB-mBJ)
  • 3.10 Basis Sets
    • 3.10.1 Slater-Type Orbital (STO)
    • 3.10.2 Gaussian-Type Orbital (GTO) ·
  • 3.11 Amsterdam Density Functional (ADF).
• CHAPTER 04: COMPUTATIONAL TECHNIQUES-
  • 4.1 ADF-BAND
  • 4.2 Brief Introduction to ADF-BAND
    • 4.2.1 Features of ADF-BAND
    • 4.2.2 Operating System for ADF-BAND
    • 4.2.3 Electronic and Structural Parameters using ADF-BAND
    • 4.2.4 Construction of wurtzite ZnS structure with ADF-BAND
    • 4.2.5 Construction of a unit cell of ZnS
  • 4.3 Computational Aspect
• CHAPTER 05: RESULTS AND DISCUSSIONS ·
  • 5.1 Electronic Properties
    • 5.1.1 Chromium Doped Zinc Sulphide: 16 atoms
    • 5.1.2 Cr Doped ZnS: 32 atoms
    • 5.1.3 Cr Doped ZnS: 64 atoms
  • 5.2 Conclusion

Zielsetzung und Themenschwerpunkte (Objectives and Key Themes)

This research investigates the electronic and magnetic properties of chromium-doped wurtzite ZnS using density functional theory (DFT). The primary objective is to understand how doping with chromium affects the material's characteristics and explore its potential applications in spintronics.

• Electronic properties of Cr-doped ZnS
• Magnetic behavior of Cr-doped ZnS
• Impact of doping on band structure and band gap
• Application of DFT and GGA+U methods in materials science
• Potential for Cr-doped ZnS in spintronic devices

Zusammenfassung der Kapitel (Chapter Summaries)

Chapter 1 introduces the research problem and outlines the research plan. It details the motivation behind studying Cr-doped ZnS and explains the methodology used in the investigation. Chapter 2 provides a comprehensive review of existing literature on the subject, analyzing previous research on the properties of ZnS and its potential applications. Chapter 3 delves into the theoretical framework underpinning the study, outlining concepts related to energy band theory, semiconductor characteristics, and computational techniques like density functional theory.

Chapter 4 focuses on the computational methods employed in the research, specifically detailing the use of ADF-BAND software and its capabilities. It discusses the process of constructing a unit cell of ZnS and the various computational aspects of the study. Chapter 5 presents the results and discussions based on the simulations, exploring the electronic properties of Cr-doped ZnS with varying concentrations of chromium. This chapter analyzes the impact of doping on the band structure, spin states, and magnetic properties of the material.

Schlüsselwörter (Keywords)

The central keywords and focus topics of the work are: chromium-doped ZnS, density functional theory, generalized gradient approximation, GGA+U, electronic properties, magnetic properties, band structure, spintronics, half-metallicity, ferromagnetism, computational materials science.