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ABSTRACT:We report a theoretical study of a new copolymer based on (Carbazole and Ethylenedioxythiophene) n (n ¼ 1-3) in their neutral and oxidized states, by using B3LYP/6-311G(d,p) calculations and thus deduce its optoelectronic properties. We discuss the influence of chain length of these properties. We also discuss the experimental UV-Visible spectrum for (PolyvinylcarbazolePoly(3,4-ethylenedioxythiophene)) (PVK-PEDOT) copolymer powder for comparison. Conformational analysis shows that there are no big changes in the structural parameters of the oligomers in their neutral form. After oxidation the oligomers become more planar and show a quinoidal character. The electronic states of monomers (Cbz-Edot) based Carbazole (Cbz) and Ethylenedioxythiophene (Edot), were elucidated by molecular orbital calculations using B3LYP/6-311G(d,p). The HOMO, LUMO, and gap energies E g were also deduced for the stable structure of the neutral, polaronic, and bipolaronic forms. Electronic transition energies and oscillator strengths of copolymers were obtained by the ZINDO, TD-DFT, and CIS methods. Band gaps of the corresponding polymers were obtained by extrapolating oligomer gaps to infinite chain lengths. These results will be compared with the experimental values obtained by optical spectrum. The optoelectronic properties of the (Cbz-Edot) 3 led us to suggest that this oligomer is a good model to reflect those of the parent polymer.

Conjugated polymers containing carbazole moieties either in the main or in the side chains have attracted much attention because of their unique electronic properties, to their high photoluminescence quantum efficiency, and thermal stability. The aim of this work is to study a new organic copolymer which combines the PVK properties and those of PHT. We will describe in this study the protocol synthesis, the chemical structure, and the electronic and vibrational properties of the resulting copolymer. The experimental and theoretical studies are combined in order to describe the properties of this material. These properties suggest this compound (PVK-PHT) to be a good candidate for optoelectronic application.

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The solar cell ITO/PEDOT/[(Cbz-Mth)-B-DT]2-A:PCBM/Al under study and the results obtained, including a power conversion efficiency of 11%. The impact of several parameters on the performance has been studied to obtain the optimal device architecture.