Raman spectra of a well-characterized natural brannerite and some synthetic brannerite samples have been collected and analysed. For the first time, all 12 theoretical Raman polyhedraof CeTi2O6 with brannerite structure have been positively identified by using quantum chemical calculations based on density functional theory (DFT) and assigned to th...
The system Y2Sn2−xZrxO7 (0.0 ≤ x ≤ 2.0) undergoes a phase transformation from ordered pyrochlore (Fdm) to defect fluorite (Fmm) actuated by the substitution of Zr for Sn. X-ray diffraction patterns map the retention of the pyrochlore structure up to x = 1.2. For samples with x = 1.4–2.0 the structure can be described as defect fluorite in broad ter...
Germany
Germany
Within the framework of the research project INES about 100 samples were investigated with respect to their morphology and short range order. Besides catalyst precursors especially carbon nanofibres as well as a few carbon nanotubes, aerogels and graphites have been investigated. In addition, the effect of modification processes of the structural f...
Topic of this thesis was the development of thin film solar cells based on microcrystalline silicon prepared by 13.56 MHz PECVD (plasma-enhanced chemical vapor deposition) at high deposition rates. Comprehensive solar cell studies, which were accompanied by material studies, resulted in the identification of the most important prerequisites for hig...
The thesis consists of two major parts. The first part contains a theoretical-experimental study of confocal micro-Raman spectroscopy on hybrid polymer coatings and an application of this spectroscopic method on PDMS-membranes. The theoretical-experimental study includes the application of a model that describes the influence of the refraction effe...
Germany
United Kingdom
This thesis concerns a study of the optical properties of the polymer poly(9,9'dioctylfluorene) (PFO). Polyfluorene polymers represent the current state-of-the-art materials for use in optoelectronic devices. Recently there has been a growing interest in investigating how changes in polymer morphology affect their optical properties and in turn how...
