This project investigates the chemical and electronic structure of organic semiconductors (OSC) chemically coupled to the surface of inorganic quantum dots (QD). Such coupled organic-inorganic nanostructures (COIN) provide a novel concept to the utilization of QDs as the active material in optoelectronic devices like photodetectors, light-emitting diodes and solar cells. Where the structural and electronic properties of the isolated components (QDs and OSCs) have been subject to extensive research activities during several decades already, changes in these properties upon establishing a chemical bond between the two constituents has been rarely investigated and poorly understood. In this proposal, I will combine photoelectron spectroscopy, X-ray standing wavefield absorption, spectroelectrochemistry and photothermal deflection spectroscopy to develop a set of rigorous spectroscopic techniques suitable for characterization of the interface between QD and OSC which is pivotal to the functionality of COINs. My aim is to demonstrate the power of these techniques in explaining the electric properties of a COIN system already studied in a previous work, namely PbS QDs coupled to the OSC tetrathiafulvalene tetracarboxylate (TTFTA). In the second part of the project, the developed procedures will be used to characterize the properties of an unexplored COIN – namely PbS QDs coupled to perylene-3,4,9,10-tetracarboxylate (PTCA) – to demonstrate their power in the rational development of new COINs with tailored optoelectronic properties and their implementation into functional devices. The results of this project will pave the way to QD-based optoelectronic devices with improved performance and broad applicabilities in technologies like light-sensing, green electric power generation and efficient lighting solutions.
