Analyzing Surface Dynamics using X-ray Photon Correlation Spectroscopy

Abstract

This thesis deals with the structural study of organic thin films, investigating the evolution of their surface morphology during processes such as thin film growth and thermal annealing. On one hand, the growth behavior of organic semiconductor systems is examined, which is crucial for predicting the final morphology and controlling the thin film properties. The additional use of thermal annealing in parallel to thin film growth also enables a targeted investigation of individual processes and simplifies the analysis, as a constant amount of deposited material is maintained and fewer experimental parameters are required. Coherent X-ray scattering, in particular using in-situ techniques such as X-ray photon correlation spectroscopy (XPCS), provides real-time insights into the dynamics of thin films. The focus is on understanding micrometer-scale dynamics, in particular the arrangement of molecular clusters such as surface islands, by extracting dynamic and kinetic time scales. However, the interpretation of XPCS data in the study of surfaces poses a challenge that can be solved by simulations of surface reorganization processes. The comparative analysis between simulated and experimental data offers the revelation of physically plausible processes and provides deep insights into the evolution of the thin film morphology during growth and annealing.

Die Dissertation ist gesperrt bis zum 01. Juli 2026 !