Untersuchung von Katalysatoren auf Gold/TiO2-Basis und optoelektronischen Halbleitern mittels Transmissionselektronenmikroskopie und Tomographie

Abstract

Gold, usually known for its inertness, can be prepared as a nanoporous bulk material showing catalytic properties. A particular advantage of this catalytic material is the stable monolithic structure, combining mechanical strength, thermal and electrical conductivity and a reproducible porosity due to self-organization during the preparation. Important structural properties are the pore size and the size of the gold ligaments. TEM (transmission electron microscopy) is a powerful tool to obtain information on these properties. Additionally, the functionalization of the nanoporous gold with TiO2 particles was investigated. For the application in catalysis of CO-oxidation, the gold can be coated with TiO2 in order to enhance catalytic activity. Furthermore semiconductor heterostructures were investigated. II-VI-based microcavities grown by molecular beam epitaxy designed for emission in the blue spectral region have been comprehensively characterized by transmission electron microscopy in bright field, dark field and scanning mode. Moreover the STEM signal for InP based semiconductors was simulated.