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Pozycja Volume conductivity of polycrystalline tetracene and p-quaterphenyl layers modified under influence of the surface adsorption(Wydawnictwo Politechniki Łódzkiej, 2021) Kania, Sylwester; Kuliński, Janusz; Kościelniak-Mucha, Barbara; Słoma, Piotr; Wojciechowski, KrzysztofVolume conductivity of thin organic layers in contact with the ambient atmosphere depends on the volume properties and on the adsorption processes on the free surface of the layer. In order to clarify the role of the surface, experiments were carried out at a temperature close to 293 K to determine the influence of the adsorption dynamics on the change of characteristic relationships observed for the transport of electric charge in vacuum, in the ambient atmosphere and in the controlled atmosphere of the ethyl alcohol vapors. The investigations were carried out for two linear tetracyclic molecular structures, i.e. p-tetraphenyl and tetracene. These molecular systems differ in organization of the rings. The results show an increase in conductivity measured for both compounds when there are the molecules capable of adsorbing to the surface and to transfer or receive charge carriers connected with the process of diffusion or drift transport in the volume of the layer. The nature of the observed increase in conductivity proves that the hopping mechanism is present in the case of conductivity of both tested materials.Pozycja Intermolecular interactions for two chosen anthracene derivatives(Wydawnictwo Politechniki Łódzkiej, 2021) Kania, Sylwester; Kuliński, Janusz; Kościelniak-Mucha, Barbara; Słoma, Piotr; Wojciechowski, KrzysztofThe nature of intermolecular interactions for anthrone and anthraquinone differs due to the symmetry of substitution of the central benzene ring, i.e. anthrone substituted with only one keto group and anthraquinone substituted with two keto groups. In order to interpret the interactions among the molecules, the interaction energies between molecules in crystals were calculated using DFT B3LYP calculations. The results reveal the consistency between calculated “lattice energies” and theirs terms and thermodynamical properties as density, boiling point and melting point of examined compounds.Pozycja A DFT study of reorganization energy of some chosen carbazole derivatives(Wydawnictwo Politechniki Łódzkiej, 2020) Kania, Sylwester; Kościelniak-Mucha, Barbara; Kuliński, Janusz; Słoma, Piotr; Wojciechowski, KrzysztofStrong efforts toward finding an organic semiconductor with a molecule characterized by a low charge transfer energy applying quantum-chemical calculations are undertaken. Density Functional Theory (DFT) calculations made for carbazole (Cz) and three isomers of benzocarbazole, benzo (a) carbazole (BaCz), benzo (b) carbazole (BbCz) and benzo (c) carbazole (BcCz) proves the possibility of lacking the growth of reorganization energy despite the molecule dimentions enlargement. Benzo(b)carbazole molecules with high longitudinal dimension of the rigid skeleton d = 9,05 Å posses the low value of reorganization energy for both hole and electron transport of 0,18 eV and 0,11 eV, respectively. We suggest that the reduction of reorganization energy may be related to the diminishing of intramolecular hydrogen interactions.Pozycja Charge carrier mobility in non-equilibrated transport in molecular materials(Lodz University of Technology Press, 2019) Kania, Sylwester; Kościelniak-Mucha, Barbara; Kuliński, Janusz; Słoma, Piotr; Wojciechowski, KrzysztofNon-equilibrated transport of charge carriers in the molecular material depends on the structure and packing of the molecules. Explanation of the measurements of the photocurrent generated with use of UV flash light in organic layer needs to define the quantity of charge carriers mobility. Definition of this quantity in the scope of some defined transport model requires the detailed analysis of generation, recombination and charge transfer between neighbouring molecules. The problem is discuss on the basis of transport properties of two anthracene derivativesPozycja Polarization of organic aromatic molecule in anionic and cationic state(Lodz University of Technology Press, 2019) Kania, Sylwester; Kościelniak-Mucha, Barbara; Kuliński, Janusz; Słoma, Piotr; Wojciechowski, KrzysztofThe modification of electron states and the change in the geometry of the structure of molecule during hopping transport of charge carriers depends on the symmetry of the molecule. During electric transport the molecule reversibly transforms from neutral state to cation when hole conductivity occurs or to anion when electron conductivity occurs. The energies of orbitals HOMO and HOMO1 of anthrone and anthrachinone are always negative, what allows for holes transport. Positive energies of LUMO and LUMO+1 orbitals of anion of anthrone and anthraquinone in structure of anion or neutral molecule make electron transport difficult.Pozycja Ab initio investigation of ethanol-tetracene interactions during adsorption(Wydawnictwo Politechniki Łódzkiej, 2018) Kania, Sylwester; Kościelniak-Mucha, Barbara; Słoma, Piotr; Wojciechowski, KrzysztofAb initio calculations presented in this work are performed to investigate the geometry, interaction energy and bonding properties of binary complexes formed between neutral ethanol and tetracene molecules. Two different geometries were applied for the study. The interaction energies between molecules in the complex posses minimum at the distance of about 3.6 A among oxygen atom in ethanol and the neighbouring carbon atom of tetracene skeleton.Pozycja Sensitivity of tetracene layer as an effect of entanglement(Wydawnictwo Politechniki Łódzkiej, 2017) Kania, Sylwester; Kościelniak-Mucha, Barbara; Kuliński, Janusz; Słoma, Piotr; Wojciechowski, KrzysztofApplication of the method of quantum-mechanical calculations allowed for studies of variability of interactions between molecules of ethanol and tetracene. Entanglement of quantum states is seen during calculations in two ways: as a change of electric dipole moment and as an increase of the basis set superposition error (BSSE) with decreasing distance between molecules under study. There are observed the dependences of the total energy of the system due to the mutual arrangement of the long axes of the molecules and due to the orientation of the bond of the oxygen atom to the carbon atom with respect to the plane of benzene skeleton of tetracene molecule.Pozycja The effect of the dipole moment on hole conductivity of polycrystalline films of two anthracene derivatives(Wydawnictwo Politechniki Łódzkiej, 2017) Kania, Sylwester; Kościelniak-Mucha, Barbara; Kuliński, Janusz; Słoma, Piotr; Wojciechowski, KrzysztofHole mobility in the polycrystalline layers of anthrone and anthraquinone differs in one order of magnitude in spite of nearly the same crystalline structure. The origin of this difference was determined with use of the quantum-mechanical calculations carried out at the density functional theory level using the B3lYP functional in conjunction with the 6-311++G(d,p) basis set. Based on theses calculations, we suppose that these difference can result from the presence of the dipol moment in the anthrone molecules.Pozycja The effect of symmetry of a molecule electronic density on the dipole moment of unit cell and hole conductivity of thin polycrystalline films of anthrone and anthraquinone.(Wydawnictwo Politechniki Łódzkiej, 2016) Kania, Sylwester; Kościelniak-Mucha, Barbara; Kuliński, Janusz; Słoma, Piotr; Wojciechowski, KrzysztofThe electronic structure of anthrone and anthraquinone molecules in the gas state and in the simulated crystal unit cell were calculated with time dependent-density functional theory (TD-DFT) method. The values of dipole moment of single molecule and of single crystal unit cell were also determined with TD-DFT method. The results of TD-DFT were compared with known crystal structures of both compounds [1,2]. For both molecules it was observed improvement of matching the length of corresponding bonds when calculated for the unit cell. Unexpectedly high value of dipole moment was calculated for the single unit cell of anthrone. This fact can be responsible for the nano-dimension properties of anthrone as the carriers mobility or high boiling point.Pozycja Effect of molecule dipolemoment on hole conductivity of polycrystalline anthrone and anthrachinone layers.(Wydawnictwo Politechniki Łódzkiej, 2015) Kania, Sylwester; Kościelniak-Mucha, Barbara; Kulinski, Janusz; Słoma, PiotrComplex analyzes were made using methods of molecular quantum mechanics to investigate the effect of the dipole moment of the molecule carrier drift mobility in polycrystalline layers composed of anthrone and anthrachinone molecules. The differences in the measured mobility values seems to be originated in the variations of the geometry of the frontier orbitals rather than the differences inherent in the crystal arrangement of these molecules, which after all, for both are nearly identical.