Matvienko O. Regularities of formation and properties of nanocomposite films based on photosensitive polymers and semiconductor nanoparticles

Thesis is devoted to the development of the preparation technology of new polymer-quantum dotes light emitting diodes based on polymer-quantum dots nanocomposites (PQDNCs) as an emitter layer. The spatial organization mechanisms of CdZnSeS QD PQDNCs thin films with two type of conjugated polymers polyvinylcarbazole (PVK) and polydioctylfluorenyl (PFO) has been demonstrated. The morphological radial distribution function and potential of mean force of the QD in PVK/QD and PFO/QD in the QD loading from 3,6 to 54 vol.% were investigated. Three types of PQDNCs films phase state (vertical, lateral and uniform) were obtained by the effect of different interface modifiers: pyridine PY and dendritic phosphonic acid possessing alkyl- (AD) or cyano- (CD) terminal groups. It is demonstrated that the nanoparticle-polymer interaction define the nanocomposite phase state. It was shown that PVK-CdZnSeS/TOPO, PVK-CdZnSeS/AD, PFO-CdZnSeS/CD favors to phase segregation of QD in the nanocomposite with formation of two-dimensional aggregates are localized near surface layer of polymer film. In contrast, PFO-CdZnSeS/TOPO, PVK-CdZnSeS/CD, PFO-CdZnSeS/AD provides the homogeneous QD distribution through the film thickness with higher photoluminescence quantum yield (~35%). The ITO/PEDOT:PSS/PFO+QD/Bu-PBD/Al (brightness 1,5 *103 Cd/m2, current efficiency 0,8 Cd/A at voltage 11 V) PQDLED structures are obtained. Key words: polymer-inorganic nanocomposite, film, quantum dot, interface modifier, light emitting diodes, phase state, luminescence quantum yield, CdSeZnS, spin-coating.