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Information × Registration Number 0211U000429, 0109U006141 , R & D reports Title Charge transport modeling and defect characterization in organic semiconductors. popup.stage_title Head Kadashchuk Andrey, Registration Date 07-02-2011 Organization Institute of physics NASU popup.description2 Using the effective medium approach an analytical model of charge transport in disordered materials was developed which gives an adequate description of the temperature, field and concentration dependence of the mobility, including the range of large concentration of charge carriers that is relevant to the organic field effect transistors (OFET), and also validates the Meyer-Neldel rule which is fulfilled for charge carrier mobility in OFET. The model provides compact analytical relations for the evaluation of material parameters and effective concentration of charge carriers in OFET channel, that allows to calculate their values for promising organic compounds. The study of the charge carrier mobility in fullerene C60 based OFET enables not only to prove the model and obtain the main material parameters, but also to link these values with the film morphology and technological conditions of their growth, and, as a result, to achieve the record values of OFET mobility. It was also proposed to use the Meyer-Neldel Energy as criterion for OFET optimization and selection of functional materials. The AFM investigation of the surface of thin films of rubrene, which were grown on the mica substrates by Hot Wall Epitaxy, reveals clear relationship of film morphology with the technological parameters, mainly growth duration and substrate temperature. The study of photoluminescence (PL) of the films and microcrystalline samples of rubrene at wide temperature interval proves the exciton nature of emission in these objects and demonstrates the dependence of the exhibition of excitonic effects (such as spectral diffusion, temperature quenching of PL) from the film morphology. By means of thermally stimulated luminescence and PL it was shown that concentration of defects and accidental impurities is low at all samples, and the traps for charge carriers and excitons in the films, which formed from spherulites, are not connected with oxidation products, but rather due to specific structure defects. Product Description popup.authors Вахнін Олександр Юрійович Кадащук Андрій Костянтинович Скришевський Юрій Антонович Фіщук Іван Іванович popup.nrat_date 2020-04-02 Close