Nanocrystal quantum dots (NQDs) are an exciting class of materials that offer a unique possibility to tailor their optoelectronic properties due to their size dependent behavior originating from quantum confinement of charge carriers. This particular aspect imparts on them significantly property differences compared to their bulk counterparts, providing numerous important opportunities in the field of nanoscale semiconductor science. One of the biggest challenges from an application point of view is to increase their processability (both in solid state and in solution phase) and to interface them with a matrix, or molecules that are able to provide electronic energy or charges. Various approaches have been used and adapted in this regard such as incorporating these materials in a polymer matrix (for OLED applications) or combining them with mesoporous TiO2 (for photovoltaic applications). Our approach is to functionalize these materials with (electro)luminescent metal complexes based on Ir(III) and Ru(II) metal ions, coordinated with ligands possessing appropriate anchoring groups that will interact with the surface of the quantum dot. These metal complexes are chosen as they are redox active chromophores with very rich photophysics (particularly emissive triplet states and electroluminescence) and electrochemistry (excellent charge transfer properties) and hence are excellent candidates for optoelectronic applications. By combining these two different classes of materials, one could fabricate a bifunctional nanoassembly with a possibility to control the band gap properties of both the constituent fragments synergistically. Understanding of basic photophysical processes that occur in such materials are of quintessential importance for the development of practical applications and further design. This thesis deals with the design of assemblies incorporating quantum dots and organic or organometallic chromophores. The photoinduced processes in such organic-inorganic hybrid nanosystems are investigated.
|Award date||25 Mar 2010|
|Place of Publication||Enschede|
|Publication status||Published - 25 Mar 2010|