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Information × Registration Number 0222U001235, 0121U114054 , R & D reports Title Multicolored organic LEDs (OLEDs) based on ambipolar compounds that exhibit thermally activated delayed fluorescence and aggregate-induced radiation (META) popup.stage_title Head Yashchuk Valerii M., Доктор фізико-математичних наук Registration Date 25-01-2022 Organization Taras Shevchenko National University of Kyiv popup.description2 The object of research is electronic processes that occur in thin organic composite films when excited. The aim of the project is to study the luminescent properties of organic materials, including those with delayed fluorescence (TADF), for use in nanoelectronics and organic LEDs. Research methods - quantum chemical calculations and optical spectroscopy. The design of molecular emitters with high quantum yield, which can effectively intercept excitation from matrix molecules in composite thin films, has been carried out. Experimental methods for recording the absorption and luminescence spectra of the studied compounds have been developed. Quantum chemical optimization of the spatial geometry of boron-containing molecules has been performed and their molecular orbitals have been calculated. It was found that the spatial geometry of these molecules is close to flat, which can provide a high quantum yield in these compounds. The absorption and luminescence spectra of these compounds in liquid solutions, one-component thin films and the Alq3 matrix have been recorded. It is established that efficient transmission of electronic excitation is possible at the concentration of impurity boric emitters less than 1-2%, and at higher concentrations the formation of aggregates, which significantly reduces the efficiency of such composite films for practical use as light-emitting layers of organic LEDs. The absorption and luminescence spectra of compounds LS26, LS26, LS29 were recorded. Preliminary results indicate that at a temperature of 300 K there is generally no delayed radiation for these compounds. At the same time at 77-200 K this radiation is present. The physical properties of new fluorene-containing organic compounds and films based on them with a significant quantum yield and high efficiency of electronic excitation energy transfer were also studied.  Product Description popup.authors Hryn Dmytro М. Dmynrenko Oksana P Losytsʹkyy Mykhaylo Yu. Myagchenko Yuriy О. Navozenko Oleksandr M. popup.nrat_date 2022-03-09 Close