46 research outputs found
Tuning of Optical and Charge Transport Properties in Linear and Star-shaped Thiophene Based Organic Materials: A DFT Insight
No full textDocumentos apresentados no âmbito do reconhecimento de graus e diplomas estrangeirosOrganic materials are fascinating class of materials for large-area and flexible devices for organic semiconductors. Among them thiophene based organic semiconductors with new molecular and macromolecularstructures were explored for the possible applications in optoelectronic devices. The present thesis is divided into five chapters. Chapter 1 includes introduction of organic materials, and their optical, electronic and charge transport properties in these materials are studied in this chapter. Literature survey on thiophene based organic materials and methodology used in achieving the goal are also discussed in this chapter. In Chapter 2, the study starts with simple thiophene based linear acene molecules and calculation of their charge transport parameters using DFT methodology. Further to make study broader and comparative, furan and selenophene based acene molecules are also included. Chapter 3 divided into two subchapters, first part of the chapter deals with optical and charge transport properties of benzotrithiophene (BTT) and their possible isomers. It is shown that the studied isomers are better for hole and electron transport materials. The second part of the chapter 3 deals with the study of optical and transport properties of oligomers of BTT (most stable isomer). It is shown that the addition of BTT-units to the core BTT, results in enhanced charge transport properties. Chapter 4 also discussed in two parts, first part of chapter 4 deals with the study of linear optical and charge transport properties of heteroatomic (O, NH and Se) analogues of BTT isomers. In the second part of chapter 4 is on the study of truxene & isotruxene, thiatruxene & isothiatruxene and their heteroatomic (N, O and Si) analogue and shown that thiatruxene are better for hole transporting material while azatruxene are better for electron transporting materials. Last chapter (i.e. chapter 5) deals with impact of replacement of central benzene ring in anthracene with different heterocyclic ring on optical and charge transport properties in anthratetrathiophene (ATT) and anthratetrathiazole (ATTz) molecules. It is also studied the effect of heteroatom (S and N) on charge transport parameters at the periphery on ATTz molecule. Overall, aim of the thesis is to design those organic materials which are having high hole and electron transport properties and may find applications in organic semiconductor materials
A comparative computational study of C N and C C bonding visible to NIR absorbing croconines
No full textOptoelectronic properties of benzotrithiophene isomers: A density functional theory study
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Impact of polycyclic aromatic hydrocarbons and heteroatomic bridges (N, S, and O) on optoelectronic properties of 1,3,5‐triazine derivatives: A computational insight
No full textImpact of replacement of the central benzene ring in anthracene by a heterocyclic ring on electronic excitations and reorganization energies in anthratetrathiophene molecules
No full textInvestigation of the influence of donor and internal acceptor on photovoltaic parameters in D-A1-π-A Dye sensitizers for efficient DSSCs
No full textIn dye-sensitized solar cells (DSSCs), the efficiency of light-to-electricity conversion is significantly influenced by the choice of donor and internal acceptor units in the dye molecules. In this study, we have designed and investigated the impact of donor groups and internal acceptor units for emphasizing the performance of DSSCs. The performance of the D-A1-π-A system has been evaluated in terms of various photovoltaic parameters such as the highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), HOMO-LUMO energy gap (HLG), excited-state oxidation potential (Edye*), free energy of electron injection (Ginj), and open-circuit voltage (VOC). DFT and TDDFT methodology is used to examine dye's electronic properties, including charge transfer dynamics, energy gaps, and photovoltaic parameters and to determine how these combinations influence light absorption, electron injection, and overall cell efficiency. Our findings indicate that D-A1-π-A architectural dyes enhance light absorption spectra ranging from 309 nm to 523 nm with variation in donor and acceptor groups and facilitating more effective electron transfer to the TiO2 semiconductor and enhancing the overall cell efficiency. Among all the studied dyes, the R4 dye containing substituted carbazole and benzotriazole unit shows a maximum efficiency of 4.48 % at a JSC value of 15 mA cm-2. Hence, this research showed the importance of molecular design of organic dyes and provided insights into the development of next-generation dyes for solar energy applications
Glutathione as a potent inhibitor against SARS CoV-2 Main protease (Mpro): Molecular docking and dynamics simulations
No full textThe emergence of a zoonotic pathogen causing disease entitled as novel coronavirus disease 2019 (COVID-19) which keeps rapid spreading and has become a pandemic threat for the entire world. Right now no medications are approved for coronaviral infection, albeit some of the medications have been attempted. Chloroquine, hydroxychloroquine, remdesivir, favipiravir, lopinavir and ritonavir are broadly used for the treatment of COVID-19. To study the interactions of glutathione with COVID-19 main protease and spike glycoprotein, computational approaches like molecular docking and molecular dynamics (MD) simulation studies are explored. The ligand-receptor interactions of glutathione-Mpro (PDB: 6LU7) and glutathione-spike glycoprotein (PDB: 6VSB) complexes were explored by using molecular docking tools. Further glutathione-Mpro complex was subjected to MD simulation study. MD simulation results shows the protein stability by exploring the RMSD and RMSF of the protein. The MD simulation also shows ligand-protein interactions as well as ligand properties. The present study concludes that glutathione shows better interactions with COVID-19 main protease in comparison to the above mentioned drugs which were used for the treatment of SARS-CoV-2
Dicyanomethylene substituted oxocarbon dianions: A comparative computational study
No full text1121-1127A comparative and computational study of various dicyanomethylene substituted dianions of squarate (SQ1-SQ3), croconate (CR1-CR4) and rhodizonate (RH1-RH7) with absorption in the visible to the near-infrared region (300-800 nm) is reported. Rhodizonate dianions show ~100 nm red-shifted absorption as compared to corresponding croconate dianions. Similarly, croconate dianions show ~100 nm red-shifted absorption as compared to the corresponding squarate dianions. Further, on increasing the number of dicyanomethylene substitutions on the central ring, there is a change in electronic properties (absorption shifts toward longer wavelength). The drastic changes in absorption properties are due to the variation in size of the central ring as shown by DFT, TDDFT and SAC-CI data
