Polymer functionalized QDs used for application and investigation

This work is about colloidal - a suspension of small particles in a liquid - semiconductor nanocrystals or the so-called Quantum Dots (QDs). They were synthesized through two different approaches and the upcoming differences - besides the question of kinetics - were investigated in order to find out the optimal parameters for the synthesis of various nanoparticles in desired diameters. Determination of optimal parameters, which depend on the shell thicknesses, to enhance the resulting absolute Quantum Yield (QY), the stability against photooxidation and the progressive destruction on the surface of the nanoparticles were investigated. Growing a spherical silica shell around their surfaces and investigation of the mechanism of its formation. Depending on the used silica sources the resulting silica shell modified nanoparticles are equipped with certain end groups that enables their use in various processes, like the lithography process. Furthermore they were attached to a gold nanowire in order to investigate some energy transfer phenomena (e.g. SERS) and to correlate the achieved data to the chain length and polarity of the functional groups.