Soft X-ray emission and resonant inelastic scattering study of polycyclic hydrocarbons

Inhaltsverzeichnis (Table of Contents)

• 1 Introduction
• 2 Soft X-Ray Spectroscopy
  • 2.1 Interaction of Electromagnetic Radiation with Electrons
    • 2.1.1 Two Step Model
    • 2.1.2 Electric Dipole Selection Rule
    • 2.1.3 Parity Selection Rule
    • 2.1.4 One Step Model
  • 2.2 Resonant Inelastic X-Ray Scattering "RIXS"
  • 2.3 Vibronic Coupling
• 3 MO- and RIXS-Calculations
  • 3.1 Hartree-Fock (HF) Self Consistent Field Method
    • 3.1.1 HF-Calculation Results
  • 3.2 Simulation of Molecular RIXS-Spectra
    • 3.2.1 Site and Symmetry Selection in Molecule RIXS
    • 3.2.2 RIXS-Simulation
• 4 Experimentals
  • 4.1 Soft X-Ray Emission Spectrometer Design
    • 4.1.1 Piezo-Slit Mechanism and Calibration
    • 4.1.2 Diffraction Gratings
    • 4.1.3 Multi Channel Plate (MCP) Detector
    • 4.1.4 Conclusion
  • 4.2 Synchrotron Radiation
  • 4.3 Organic Semiconductors
    • 4.3.1 Sample Preparation
  • 4.4 NEXAFS Spectroscopy
• 5 Results
  • 5.1 NEXAFS of Aromatic Hydrocarbons
    • 5.1.1 Tetracene NEXAFS
    • 5.1.2 Perylene NEXAFS
    • 5.1.3 Coronene NEXAFS
    • 5.1.4 Excitonic Character of the Hydrocarbon NEXAFS-Spectra
    • 5.1.5 Conclusion
  • 5.2 Hydrocarbon Soft X-Ray Emission Spectra
    • 5.2.1 First Inspection of Hydrocarbon SXE
    • 5.2.2 RIXS-Spectra Corrections
    • 5.2.3 Nonresonant SXE versus Valence Band Photoemission
    • 5.2.4 Site and Symmetry Selection in Hydrocarbon RIXS-Spectra
    • 5.2.5 Band Dispersion-Effects in the RIXS-Spectra
    • 5.2.6 Vibronic Coupling
    • 5.2.7 Spectator Shifts and Screening
• 6 Summary
• A Irreducible Representation
• B Grating Efficiency
• C Deutsche Zusammenfassung

Zielsetzung und Themenschwerpunkte (Objectives and Key Themes)

This dissertation investigates the electronic structure of polycyclic aromatic hydrocarbons using soft X-ray emission and resonant inelastic X-ray scattering (RIXS) spectroscopy. The main objective is to utilize these techniques to understand the fundamental electronic properties of these complex organic molecules and their potential applications in organic electronics.

• Electronic Structure of Polycyclic Aromatic Hydrocarbons
• Soft X-Ray Emission Spectroscopy and Resonant Inelastic X-Ray Scattering
• Molecular Orbital and RIXS Calculations
• Site and Symmetry Selection in Molecular RIXS
• Vibronic Coupling and Spectator Shifts in the RIXS Spectra

Zusammenfassung der Kapitel (Chapter Summaries)

Chapter 1 introduces the concept of soft X-ray spectroscopy and its application to the study of polycyclic aromatic hydrocarbons. It discusses the theoretical background of the techniques used in the study and the challenges involved in investigating these complex molecules. Chapter 2 provides a detailed explanation of the physical principles governing soft X-ray emission and RIXS spectroscopy. It delves into the interactions of electromagnetic radiation with electrons, the two-step model, and selection rules that govern these processes. Chapter 3 focuses on computational methods used to simulate molecular RIXS spectra. It discusses the Hartree-Fock (HF) self-consistent field method and its implementation in simulating RIXS data. Chapter 4 describes the experimental setup used in the study, including the design of the soft X-ray emission spectrometer, the synchrotron radiation source, and the sample preparation techniques. Chapter 5 presents the results of the experimental investigation. It explores the NEXAFS spectra of various aromatic hydrocarbons, analyzes the soft X-ray emission spectra, and investigates the effects of vibronic coupling and spectator shifts in the RIXS spectra. Chapter 6 summarizes the key findings of the dissertation and highlights the significant contributions of this research to the understanding of the electronic properties of polycyclic aromatic hydrocarbons.

Schlüsselwörter (Keywords)

This dissertation focuses on the application of soft X-ray emission and resonant inelastic X-ray scattering spectroscopy to the study of polycyclic aromatic hydrocarbons. It delves into their electronic structure, molecular orbital calculations, site and symmetry selection in RIXS spectra, and investigates the vibronic coupling and spectator shifts observed in these complex organic molecules. These techniques provide valuable insights into the electronic properties of polycyclic aromatic hydrocarbons, offering potential for advancements in organic electronics.