ИСТИНА

https://www.rug.nl/research/portal/publications/photoluminescence-and-raman-spectroscopy-of-highly-ordered-organic-semiconductor-structures(43e1fe88-5fb2-4b64-96a3-6a6284541fbf).html Organic optoelectronics is a rapidly growing field of fundamental and applied research promising cheap, light weighted, mechanically flexible, and – for some applications – even semitransparent devices. The state-of-the-art organic semiconductors stand as the basis for indispensable optoelectronic devices such as light-emitting diodes, photovoltaic devices and, in a longer term, light-emitting transistors and injection lasers. Apart from the chemical structure of the molecules, such characteristics of their solid phase as molecular packing, crystallinity, short- and long-range order, impurities, and doping govern electrophysical and photophysical processes in an organic semiconductor. Molecular packing is one of the key features that allows for fine-tuning the architecture of the organic semiconductor to gain new material properties. This Thesis focuses on the understanding of photophysics and morphology in ordered organic semiconductor systems – semicrystalline polymer-fullerene blended films, various types of luminescent single crystals and monolayers. The Thesis aims to answer the following questions: How could the polymer crystallinity be monitored during thermal annealing the polymer-fullerene organic photovoltaic devices? What are the fundamental dynamic processes that control the exciton dynamics, energy transfer efficiency, and luminescence polarization in doped organic single crystals? What are the differences in luminescence dynamics of the crystalline monolayers and single crystals? Experimentally, the photophysics and morphology are probed by ultrafast photoluminescence and Raman spectroscopies. Such an extensive study in various highly ordered organic semiconducting structures provides the essential connections between the fast photophysics and the structural properties of the material, and aims to develop new approaches for improving the performance of organic optoelectronic devices.