Z. El Malki; M. Haddad;M. Bouachrine; M. Hamidi; J-P Lere-Porte; F. Serein-Spirau; L. Bejjit
Abstract
In this work the geometrical and electronic properties of (Carbazole-3.4-Ethylenedioxythiophene) (Cbz-Edot) based alternating donor-acceptor conjugated oligomers were studied by the density functional theory (DFT) at the B3LYP level with 6-31G(d) basis set. The acceptors investigated include thiazole ...
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In this work the geometrical and electronic properties of (Carbazole-3.4-Ethylenedioxythiophene) (Cbz-Edot) based alternating donor-acceptor conjugated oligomers were studied by the density functional theory (DFT) at the B3LYP level with 6-31G(d) basis set. The acceptors investigated include thiazole (Z), thiadiazole (D), thienopyrazine (TP), thienothiadiazole (TD), benzothiadiazole (BT) and thiadiazolothienopyrazine (TPD). A low band gap will be expected in polymers containing donor-acceptor (D-A) repeating units. In order to predict the band gaps for guiding the synthesis of novel materials with low band gaps, we apply quantum-chemical techniques to calculate the band gaps in several oligomers. The results have been compared with those of thiophene and 3,4-ethylenedioxythiophene polymers with donor-acceptor fragment. The lowest excitation energies (Eex) and the maximal absorption wavelength (λabs) are studied using the time dependent density functional theory (TD-DFT), method. The electronic transitions of the absorption spectrum derived by TD-DFT method give useful structural and electronic information for designing novel conducting organic polymer materials. The theoretical results suggest that both the acceptor strength and the stable geometry contribute significantly to the electronic properties of alternating donor-acceptor conjugated copolymers.
M. Amine; M. Hamidi; S.M. Bouzzine; A. Amine; M. Bouachrine
Abstract
Organic conjugated polymers based on heterocylic ring exhibit semiconducting properties associated with the π molecular orbitals delocalized along the polymer chains. These materials have attracted much interest for potential applications in optoelectronic devices due to their unique electronic and ...
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Organic conjugated polymers based on heterocylic ring exhibit semiconducting properties associated with the π molecular orbitals delocalized along the polymer chains. These materials have attracted much interest for potential applications in optoelectronic devices due to their unique electronic and photonic properties. Recently, interesting studies have been devoted to the synthesis, characterization, physical and chemical properties and variety of these materials. In this work, a quantum-chemical investigation on the structural and opto-electronic properties of new polymer named poly (4-methylythioazole-2.5- diyl)s is carried out. We present a detailed DFT study of geometrical structures and electronic properties of this organic material. Calculated results are compared with experimental data and based on such comparison we try first, to propose an oligomer model and then, to obtain a qualitative understanding the properties of polymer. We discuss the influence of chain length on structural and optoelectronic properties. The numerical predictions are compared to our experimental results. The ground state optimized structures and energies are obtained using the molecular orbital theory and the DFT (B3LYP/6-31G (d)) calculations.
