Flame Spray Synthesis of Semiconducting Oxide Nanomaterials - Fundamental Process Characterization and Control of Product Properties
In the presented thesis the production of semiconducting nanoparticles by flame spray pyrolysis - a bottom up particle synthesis approach - is investigated. The main focus of this work was divided into two parts:
- A mechanistic approach, which illuminated the particle formation mechanisms within the spray flame. To that end, different optical techniques were carried out by the Institute of Engineering Thermodynamics, Erlangen, Germany.
- A materials synthesis approach, which investigated the connection between process parameters and specific product properties. There we could prove and extend trends regarding the control of particle size, crystallinity and dispersability. Furthermore, amorphous semiconducting indium-zinc oxide was synthesized and the particles were characterized with a special focus on the indium to zinc composition and its influence on crystallinity. For thin film formation a pulsed direct deposition device was developed and particles were deposited by controlled direct injection of wafer substrates into the combustion zone of the flame. Dense, homogeneous and crack-free films were achieved, These films could be efficiently used in thin-film transistors fabricated by our co-workers at the Chair of Electron Devices, Erlangen, Germany.