Papers by Mohamed Bourass
Journal of Photochemistry and Photobiology A: Chemistry
SSRN Electronic Journal, 2022
The aim of this work is to study the optoelectronic properties and photovoltaic (PV) of organic m... more The aim of this work is to study the optoelectronic properties and photovoltaic (PV) of organic material based on anthracene and pyrrole units named Anthracene-Pyrole and noted ANT-PPY; the discussion and interpretation of the obtained results will be devoted to the characterization based on an theoretical analysis (FTIR, UV-vis and PL), using the method DFT level of the B3LYP (Becke three-parameter Lee-Yang-Parr) exchange correlation functional with 6-31G (d, p). Electronic charge distribution and the intramolecular charge transfer (ICT) and electron density difference maps (EDDM) between the excited and ground states of copolymer have been examined through a computational approach with the density functional theory (DFT) and time-dependent-DFT (TD-DFT) and CAM-B3LYP methods. Non-linear optical (NLO) property of the copolymer, the dipole moment, polarizability and first-order hyperpolarizability have been studied and interpreted in this study. The obtained results show that optoelectronic qualities and photovoltaic properties are related (PV) of the copolymer suggest that this copolymer can be a better candidate for used in organic electronic devices that will be mentioned and studied.
The research in the organic p-conjugated molecules has become one of the most interesting topics ... more The research in the organic p-conjugated molecules has become one of the most interesting topics in chemistry physics and materials science. To improve the quality of device of the solar cells, it's important to highlight the low band gap for these materials. The electronic properties, geometries and absorption of these studied compounds are determined by using the DFT method (density functional theory) and TD/DFT (time-dependent density functional theory). The theoretical knowledge of the HOMO and LUMO energy levels of the components is major in studying organic solar cells. In this work, new materials p-conjugated containing heterocyclic structures will be studied using a quantum analysis DFT. The objective is to determine the structural and optoelectronic parameters (HOMO, LUMO, Egap, Voc…) starting from the optimized structures of studied materials. So these parameters have been calculated and reported. The effects of the structure length and the substituents on the geometri...
This research is a fundamental study of the structure activity relationship of a series of novel ... more This research is a fundamental study of the structure activity relationship of a series of novel N-phenylbenzamide and N-phenylacetophenone. In this study we used the quantum chemical calculation using density functional theory DFT (B3LYP/6-31G) methods to determine the quantum chemical parameters,the electronics and energy associated with molecules studied. The QSAR studies have been performed on twenty one molecules of a series of novel N-phenylbenzamide and N-phenylacetophenone analogues. The compounds are characterized by the effect for the development of anti-EV 71 drugs. A multiple linear regression (MLR) and a multiple non-linear regression procedure were been carried out to develop the relationships between descriptors and molecular properties antiviral activity. The statistical results indicate that these models are statistically significant and represent a very good stability for high values of the correlation coefficients (R(pIC50 = 0.87) and R(pTC50) = 0.95 for MLR and R...
BHJ or dye-sensitized solar cells (DSSC) have emerged as an economically viable photovoltaic tech... more BHJ or dye-sensitized solar cells (DSSC) have emerged as an economically viable photovoltaic technology. Despite the many studies in this area, it is clear that the photo-conversion efficiencies have not yet exceeded 12% with this type of cells. In this work, the main goal is to study the π-conjugated molecules used in photovoltaic solar cells in order to enhance their efficiency. This study was done through DFT and TD-DFT quantum methods, with the aim to predict optoelectronic properties of these materials. These works contain mainly theoretical calculations which aim firstly to engage in predictive studies to model the electronic and optical properties of different sequences based on conjugates thienopyrazine and thiophene to select, before any synthesis step, good fragments include for optimized properties and secondly to assess in electronic spectroscopy (absorption, emission, photoelectron UV, ...) in their relevant photovoltaic cells.
To understand the importance of the organic material of type donor-π-acceptor dyes (D-π-A), used ... more To understand the importance of the organic material of type donor-π-acceptor dyes (D-π-A), used for dyesensitized solar cells (DSSCs), we present in this paper the result of six compounds based on thienopyrazine (D1-D6) studied by density functional theory (DFT) and time dependent DFT (TD-DFT) approaches to shed light on how the π-conjugation order influence the performance of the dyes. The electron acceptor (anchoring) group was 2-cyanoacrylic acid for all dyes whereas the electron-donor unit varied and the influence was investigated. The theoretical results have shown that TD-DFT calculations using the Coulomb attenuating method CAM-B3LYP with the polarized split-valence 6-31G (d, p) basis sets and the polarizable continuum model (PCM) were reasonably capable of predicting the excitation energies, the absorption and the emission spectra of the dyes. The study of structural, electronic and optical properties for these dyes could help to design more efficient functional photovoltai...
Journal of Molecular Structure, 2021
Research on Chemical Intermediates, 2020
A theoretical study on four organic dyes based on bis(4-hexyloxy)triphenylamine as donor and elec... more A theoretical study on four organic dyes based on bis(4-hexyloxy)triphenylamine as donor and electron acceptor cyanoacrylic acid with a donor–π–acceptor structure (D–π–(D–A–)–A) using DFT/DFT (TD-DFT)/6-31G( d , p ) having a difference of π spacer was designed. The theoretical study of the structural, electronic and optical properties of these dyes (D1, D4) suggests that these materials would be excellent sensitizers as a candidate for the production of dye solar cells, due to the efficient photoinduced electron transfer and strong absorption as well as the electronic properties (HOMO, LUMO, E gap ) low band gap, The improved light-harvesting efficiency and free energy change of electron injection (Δ G inject ), of new designed sensitizers revealed that these materials would be excellent sensitizers. This theoretical designing paves the way for experimentalists to synthesize more efficient sensitizers for solar cells.
New Journal of Chemistry, 2019
The compounds with the D–π–A structure are found to be good candidates for blue-emitting materials.
Pure and Applied Chemistry, 2019
In order to understand the electronic contribution of the thienopyrazine building block on the el... more In order to understand the electronic contribution of the thienopyrazine building block on the electronic properties of π-conjugated systems, small molecules containing thiophene and thienopyrazine moieties are synthesized and jointly studied by theoretical (DFT) and experimental methods (UV-Vis, UPS). Taking advantages of these preliminar attractive results, four low band gap extended structures have been elaborated on the base of Donor-Acceptor-Donor sequences (DAD); these elongated π-conjugated molecules exhibit noticeable electronic and absorption properties spreading from the near UV to NIR regions.
Canadian Journal of Chemistry, 2019
Onze nouvelles molécules organiques de structure donneurs-espaceur-accepteurs (D-π-A) utilisées p... more Onze nouvelles molécules organiques de structure donneurs-espaceur-accepteurs (D-π-A) utilisées pour les cellules solaires organiques (OSC) basées sur la thiénopyrazine et le thiophène ont été étudiées par la théorie de la densité fonctionnelle (DFT) et la théorie de la densité fonctionnelle dépendante de temps DFT (TD-DFT), pour expliquer comment l’ordre de conjugaison influe sur les performances des cellules solaires. Le groupe accepteur d’électrons (ancrage) était composé de 2-cyanoacrylique pour tous les composés, tandis que l’unité donneuse d’électrons était variée et que son influence fut étudiée. Les résultats théoriques ont montré que les calculs TD-DFT, avec une fonction hybride d’échange – corrélation utilisant la méthode d’atténuation de Coulomb (CAM-B3LYP) en conjonction avec un modèle de solvatation à cycle continu polarisable (modèle de continuum polarisable, PCM) combinée avec la base 6-31G(d,p), était raisonnablement capable de prédire les énergies d’excitation, les ...
Comptes Rendus Chimie, 2019
Journal of Computational Electronics, 2019
Density functional theory and time-dependent approaches are applied for theoretical investigation... more Density functional theory and time-dependent approaches are applied for theoretical investigation of a new class of novel carbazole-based d-D-π-A-type dyes, where the carbazole moiety is the main electron donor, bithiophene behaves as a π-bridge, and cyanoacetic acid as an electron acceptor for all the studied dyes, whereas the terminal electron donor unit is varied to thiophene, thienothiophene, carbazole, dimethoxyphenyl, and indole. The influence of the terminal electron donor on the optoelectronics properties is investigated for the dyes in isolated state and in chloroform solvent. Their absorption spectra and electronic and structural properties are evaluated and discussed. The theoretical results show that all the dyes exhibit excellent optoelectronic properties. In particular, D5 with indole as the terminal electron donor moiety has potential for use as a sensitizer for nanocrystalline TiO 2 solar cells based on its red-shifted absorption spectrum, reduced energy gap, lowest λ total value, and higher ΔG Inject and ΔG Reg values.
Journal of Molecular Modeling, 2019
In this paper, we present a series of sensitizers to shed light on the influence of π-spacers on ... more In this paper, we present a series of sensitizers to shed light on the influence of π-spacers on the performance of dye-sensitized solar cells. We have accurately calculated key properties in energy conversion, including sunlight absorption, electron injection, electron/hole reorganization energy, ionization potential (IP) and electronic affinity (EA). We chose a series of donor-π-acceptor dyes based on methyl-indole-carbazole as the electron donor group and cyano-acrylic acid as an acceptor with various πconjugated systems. The results obtained show that, with incorporation of the thieno(3,4-b)pyrazine in the two π-spacer parts, D4 may be the best candidate among the dyes studied, due to its many advantages such as low gap energy, red-shift absorption spectra, large ΔG Inj , low hole/electron reorganization energies, low IP and high EA, which indicate its better optoelectronic properties, which present more balanced transport rates and provide good injection ability.
Research on Chemical Intermediates, 2018
We used density functional theory at B3LYP level with 6-31G(d,p) basis set for all atoms to study... more We used density functional theory at B3LYP level with 6-31G(d,p) basis set for all atoms to study the electrochemical, photovoltaic, and absorption properties of four new organic p-conjugated donor-p-acceptor structures based on diketo-pyrrolo-pyrrole for use in dye-sensitized solar cells (DSSCs). Meanwhile, the cyanocarboxylic acid function of these compounds was used as electron acceptor to attract electrons from the donor unit via the p-spacer and also to attach the dye to a TiO 2 surface. This study focuses on the effect of the p-spacer on structural, electronic, and photovoltaic properties including the highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), energy gap, density of states (DOS), ultraviolet-visible (UV-Vis) absorption spectrum, free energy change of electron injection DG inject , light harvesting efficiency, intramolecular charge transfer, and electrochemical properties (chemical potential l, electronegativity v, and global hardness g). Moreover, the structure-properties correlation for all dyes is discussed. Our quantum calculations reveal that the dye based on furan as p-spacer (Dye-Fu) may represent a potential electron donor for use in DSSCs.
New Journal of Chemistry, 2017
A triphenylamine compound bridged with a pyrazine derivative was characterized theoretically usin... more A triphenylamine compound bridged with a pyrazine derivative was characterized theoretically using DFT and TD-DFT as a promising acceptor in BHJs.
Optical and Quantum Electronics, 2019
The aim of this work is to search for new molecules with a photovoltaic performance for use in th... more The aim of this work is to search for new molecules with a photovoltaic performance for use in the field of organic solar cells. To achieve this goal, starting from a series of D-AD bis-dipolar emissive oligoarylfluorenes and derivatives, the acceptor unit (A) is replaced by other different acceptors to improve their electronic optical and photovoltaic properties. The calculations were done using the B3LYP method with the base 6-31G(d,p) to optimize the geometry of the studied molecules and to determine the energies of HOMO, LUMO and band Gap. On the other hand, in order to study the electronic excitation spectra, the TD-B3LYP/6-31G (d,p) were used to calculate the absorption properties (λ max , OS). The results show that the designed molecules proposed here exhibit better performances including lower HOMO energy, a larger absorption range and better theoretical open circuit voltage (V OC). These compounds can be used as potential electron donors in organic solar cells Hetero-junction (BHJ), thanks to their better electronic and optical properties and good photovoltaic PV.
Advances in Physical Chemistry, 2017
Karbala International Journal of Modern Science, 2017
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Papers by Mohamed Bourass