The optoelectronic properties of new dyes based on thienopyrazine

International audienceIn this article, we present the quantum result of six dyes based on thienopyrazine (D1–D6) with donor–π–acceptor structure (D–π–A) using DFT/B3LYP/6-31G(d,p) and TD-DFT/CAM-B3LYP/6-31G(d,p) levels. The donor unit varied and the influence was investigated. The study of structural, electronic, and optical properties of these dyes could help design more efficient functional photovoltaic organic materials. Key parameters in close connection with the short-circuit current density (J sc ) including light harvesting efficiency, injection driving force (ΔG inject ), and total reorganization energy (λ total ) are discussed in this work

DFT study of molecular properties , potential energy surface and Stability of the dioxide of the group 12 M(O2): M=Zn, Cd and Hg

Two potential energy surfaces PESs in the lowest energy multiplicities triplet 3A'' and singlet 1A' for the dioxide of heavy metals of the group 12 Zn(O2), Cd(O2) and Hg(O2) have been studied through DFT methods with the B3LYP functional. The core electrons of Zn (30 electrons), Cd (48 electrons) and Hg (60 electrons) are represented by pseudopotential ECP and the valences electrons are explicitly treated with the quasi-relativistic basis MWB and the full relativist basis AVTZ-PP. Both linear C∞v and D∞h or bent Cs and cyclic C2v structures of M(O2)have been considered in this work. The different pathways of dissociation and formation of M(O2) and their dissociative limits M+O2 and MO+O have been examined to discuss the stability of these molecules. Structural, spectroscopic and thermodynamic properties of stationary points are presented and compared with previous theoretical and experimental studies

Effects of the terminal donor unit on the photovoltaic parameters of benzocarbazole-based dyes for DSSCs: DFT/TD-DFT investigations

In this paper, a computational study on five organic p-conjugated molecules based benzocarbazole (BC) is reported. These new dyes were characterize theoretically by density functional theory (DFT) and time-dependent (TD-DFT) approaches. Different electron side groups were introduced as a terminal donor to investigate their effects on the electronic structure; the HOMO, LUMO, free energy of electron injection (∆Ginject), free energy regeneration (∆Greg), open circuit voltage (Voc), the gap energy and UV–visible absorption spectra analysis of these dyes have been reported and discussed. The calculated results show that dye M3 with phenoxazine as a terminal donor groups can be used as a potential donor of electron in DSSCs, due to its best electronic and optical properties and good photovoltaic

Repliements induits par l'asparagine et l'acide aspartique dans les peptides

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

DFT, DFTB and TD-DFT theoretical investigations of π-conjugated molecules based on thieno[2,3-b] indole for dye-sensitized solar cell applications

In this study, the electrochemical, photovoltaic and absorption properties of the new designed organic sensitizers dyes: Dye-1, Dye-2, Dye-3 and Dye-4 based on Dye-R, of D-π-A architecture, before and after binding to the TiO2 cluster surface on the ability to inject electrons to the surface. The D donor is the thieno[2,3-b] indole, π-spacer is thiophene, A acceptor is cycnoacrylic acid (CA). The properties were calculated using functional density theory (DFT), time-dependent TD-DFT and the density-functional tight-binding (DFTB) approach. Our study also focused on the analysis of the effects of the introduction of the auxiliary donor (D′)/acceptor (A′) groups on the main photovoltaic properties of the reference molecule Dye-R and to study the relationship between the molecular structure and optoelectronic properties. The analysis of the calculated properties of the new designed compounds D-D′-π-A (Dye-1), D-π-D′-A (Dye-2), D-A′-π-A (Dye-3) and D-π-A′-A (Dye-4), where A′ is benzothiadiazole and D′ is 9,9-diethyl-9H-fluorene, indicate that the molecular architecture has a significant effect on various properties of the studied dyes and that nature (donor D ′or acceptor A′) of the introduced groups, as well as the choice of their locations with respect to the π bridge, is of great importance. Indeed, among the four designed compounds Dye-4 (D-π-A′-A) and Dye-3 (D-A′-π-A) display significantly better properties than those of the reference molecule Dye-R (D-π-A) and of the two other designed dyes Dye-1 (D-D′-π-A), Dye-2 (D-π-D′-A). © 2022 Elsevier B.V

DFT theoretical investigations of π-conjugated molecules based on thienopyrazine and different acceptor moieties for organic photovoltaic cells

In this work, theoretical study by using the DFT method on eleven conjugated compounds based on thienopyrazine is reported. Different electron side groups were introduced to investigate their effects on the electronic structure; The HOMO, LUMO and Gap energy of these compounds have been calculated and reported in this paper. A systematic theoretical study of such compound has not been reported as we know. Thus, our aim is first, to explore their electronic and spectroscopic properties on the basis of the DFT quantum chemical calculations. Second, we are interested to elucidate the parameters that influence the photovoltaic efficiency toward better understanding of the structure–property relationships. The study of structural, electronic and optical properties for these compounds could help to design more efficient functional photovoltaic organic materials

DFT theoretical investigations of p-conjugated molecules based on thienopyrazine and different acceptor moieties for organic photovoltaic cells

International audienceIn this work, theoretical study by using the DFT method on eleven conjugated com- pounds based on thienopyrazine is reported. Different electron side groups were introduced to investigate their effects on the electronic structure; The HOMO, LUMO and Gap energy of these compounds have been calculated and reported in this paper. A systematic theoretical study of such compound has not been reported as we know. Thus, our aim is first, to explore their electronic and spectroscopic properties on the basis of the DFT quantum chemical calculations. Second, we are interested to elucidate the parameters that influence the photovoltaic efficiency toward better under- standing of the structure-property relationships. The study of structural, electronic and optical properties for these compounds could help to design more efficient functional photovoltaic organic materials