A theoretical investigation of tetrahydroquinoline dyes with different spacers used for sensitized solar cells

2011 ◽  
Vol 89 (8) ◽  
pp. 978-986 ◽  
Author(s):  
Jie Xu ◽  
Lei Wang ◽  
Li Liu ◽  
Zikui Bai ◽  
Luoxin Wang ◽  
...  
Keyword(s):  
Absorption Spectra ◽  
Density Functional ◽  
Photovoltaic Performance ◽  
Molecular Structures ◽  
Absorption Bands ◽  
Functional Theory ◽  
Spacer Length ◽  
Solvent Interaction ◽  
Td Dft ◽  
Sensitized Solar Cells

The molecular structures and absorption spectra of three tetrahydroquinoline dyes (C2–1, C1–1, and C1–5) with a tetrahydroquinoline moiety as the electron donor, a cyanoacrylic acid moiety as the electron acceptor, and different thiophene-containing electron spacers were investigated by density functional theory (DFT) and time-dependent DFT (TD-DFT). The calculated geometries indicate that a strong conjugation is formed in the dyes and the conjugate length increases with the increase of spacer length. The interfacial charge transfer between the semiconductor electrode and the tetrahydroquinoline dyes are electron-injection processes from the excited dyes to the semiconductor conduction band. The simulated absorption bands are assigned to π–π* transitions, which exhibit appreciable red-shift with respect to the experimental bands owing to the lack of direct solute–solvent interaction and the inherent approximations in TD-DFT. Moreover, the effect of different spacers on the molecular structures, absorption spectra, and photovoltaic performance were comparatively discussed.

scholarly journals Unraveling the electrochemical and spectroscopic properties of neutral and negatively charged perylene tetraethylesters

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christian Wiebeler ◽  
Joachim Vollbrecht ◽  
Adam Neuba ◽  
Heinz-Siegfried Kitzerow ◽  
Stefan Schumacher
Keyword(s):  
Absorption Spectra ◽  
Density Functional ◽  
Energy Levels ◽  
Spectroscopic Properties ◽  
Absorption Bands ◽  
Functional Theory ◽  
Vertical Excitation ◽  
Hartree Fock ◽  
Tauc Plot ◽  
Electrochemical Approach

AbstractA detailed investigation of the energy levels of perylene-3,4,9,10-tetracarboxylic tetraethylester as a representative compound for the whole family of perylene esters was performed. It was revealed via electrochemical measurements that one oxidation and two reductions take place. The bandgaps determined via the electrochemical approach are in good agreement with the optical bandgap obtained from the absorption spectra via a Tauc plot. In addition, absorption spectra in dependence of the electrochemical potential were the basis for extensive quantum-chemical calculations of the neutral, monoanionic, and dianionic molecules. For this purpose, calculations based on density functional theory were compared with post-Hartree–Fock methods and the CAM-B3LYP functional proved to be the most reliable choice for the calculation of absorption spectra. Furthermore, spectral features found experimentally could be reproduced with vibronic calculations and allowed to understand their origins. In particular, the two lowest energy absorption bands of the anion are not caused by absorption of two distinct electronic states, which might have been expected from vertical excitation calculations, but both states exhibit a strong vibronic progression resulting in contributions to both bands.

scholarly journals A Theoretical Investigation of Decorated Novel Triazoles as DSSCs in PV Devices

2021 ◽  
Author(s):  
Louis-Charl Cloete Coetzee ◽  
Adedapo Adeyinka ◽  
Nomampondo Magwa
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Dye Sensitized Solar Cells ◽  
Fluorescence Emission ◽  
Photovoltaic Properties ◽  
Functional Theory ◽  
Dye Sensitized ◽  
Td Dft ◽  
Photovoltaic Applications ◽  
Sensitized Solar Cells

Abstract Some novel metal-free 1,2,4-triazole compounds A1-A8, based on the 3,5-bis(2-hydroxyphenyl)-1,2,4-triazole derivatives were examined for Photovoltaic properties using density functional theory (DFT) and time dependent density functional theory (TD-DFT) calculations for the use of dye sensitized solar cells (DSSCs). Through deductive logic, the fluorescence emission (Φf) and charge collection (ηc) efficiencies of these compounds as dyes were obtained and used to determine each dye’s incident conversion efficiency (IPCE). Furthermore, these parameters were also employed to assess the dye’s potential for photovoltaic technology. However, this technique is more suitable to predict the suitability of the dye for photovoltaic applications, and cannot measure the efficiency of DSSCs

POM-based dyes featuring rigidified bithiophene π linkers: potential high-efficiency dyes for dye-sensitized solar cells

2020 ◽  
Vol 44 (21) ◽  
pp. 8996-9003
Author(s):  
Yu Gao ◽  
Wei Guan ◽  
Li-Kai Yan ◽  
Yan-Hong Xu
Keyword(s):  
Solar Cells ◽  
Density Functional ◽  
High Efficiency ◽  
Dye Sensitized Solar Cells ◽  
Functional Theory ◽  
Dye Sensitized ◽  
Acceptor Group ◽  
Td Dft ◽  
C And N ◽  
Sensitized Solar Cells

A series of POM-based dyes with a triphenylamine electron donor group, cyanoacrylic acid electron acceptor group and different π linkers of thiophene derivatives were systematically investigated to analyze the influence of a rigidified bithiophene with fastening atoms (C and N) on the performance of dye-sensitized solar cells (DSSCs) based on density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations.

scholarly journals Computational studies of Ni(II) photosensitizers complexes containing 1,1′-bis(diphenylphosphino)ferrocene and dithio ligands

2020 ◽  
Vol 98 (4) ◽  
pp. 194-203 ◽  
Author(s):  
Sefia Brahim ◽  
Houari Brahim ◽  
Stéphane Humbel ◽  
Ali Rahmouni
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Dye Sensitized Solar Cells ◽  
Substituent Effects ◽  
Spectroscopic Properties ◽  
Basis Sets ◽  
Functional Theory ◽  
Square Planar ◽  
Td Dft ◽  
Sensitized Solar Cells

Detailed theoretical studies of Ni(II) complexes in a distorted square planar form and containing dithio and (P, P) chelating ligands were performed. These Ni(II) complexes are investigated for their use in dye-sensitized solar cells (DSSC). Structures and UV–vis spectra are calculated at density functional theory (DFT) and time-dependent density functional theory (TD-DFT) theories using B3LYP and CAM-B3LYP functionals and 6-31G(d,p) and 6-31G+(d) basis sets. Geometry optimizations result in excellent agreement with the experimental results. Moreover, the analysis of the frontier molecular orbitals (FMOs) allowed a detailed assignment and a clear analysis of the electronic transitions. The TD-DFT calculations reproduce the main spectroscopic properties observed and substituent effects. The results reveal that all absorption spectra are characterized by mixed character mainly dominated by metal to ligand and ligand to ligand charge transfers (MLCT and LLCT). We unveil how the substituent variations affect the DSSCs features of the complexes.

scholarly journals Terahertz Absorption Spectroscopy of Benzamide, Acrylamide, Caprolactam, Salicylamide, and Sulfanilamide in the Solid State

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Ye Jiang ◽  
Fengshan Zhou ◽  
Xiaodong Wen ◽  
Limin Yang ◽  
Guozhong Zhao ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Solid State ◽  
Absorption Spectra ◽  
Density Functional ◽  
Room Temperature ◽  
Solid Phase ◽  
Absorption Bands ◽  
Functional Theory ◽  
Terahertz Absorption ◽  
Thz Absorption

Terahertz (THz) absorption spectra of the similarly structured molecules with amide groups including benzamide, acrylamide, caprolactam, salicylamide, and sulfanilamide in the solid phase at room temperature and 7.8 K for salicylamide are reported and compared to infrared vibrational spectral calculations using density functional theory. The results of THz absorption spectra show that the molecules have characteristic bands in the region of 0.2–2.6 THz (~7–87 cm−1). THz technique can be used to distinguish different molecules with amide groups. In the THz region benzamide has three bands at 0.83, 1.63, and 1.73 THz; the bands are located at 1.44 and 2.00 THz for acrylamide; the bands at 1.24, 1.66 and 2.12 THz are observed for caprolactam. The absorption bands are located at 1.44, 1.63, and 2.39 THz at room temperature, and at 1.22, 1.46, 1.66, and 2.41 THz at low temperature for salicylamide. The bands at 1.63, 1.78, 2.00, and 2.20 THz appear for sulfanilamide. These bands in the THz region may be related to torsion, rocking, wagging, and other modes of different groups in the molecules.

Role of heteroatoms and substituents on the structure, reactivity, aromaticity, and absorption spectra of pyrene: a density functional theory study

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Bapan Saha ◽  
Pradip Kumar Bhattacharyya
Keyword(s):  
Density Functional Theory ◽  
Absorption Spectra ◽  
Density Functional ◽  
Structural Parameters ◽  
Visible Absorption ◽  
Functional Theory ◽  
Solvent Phase ◽  
Visible Spectra ◽  
Td Dft ◽  
Uv Visible

Abstract Effect of heteroatoms viz. BN and substituents viz. –Me (methyl), –OH (hydroxyl), –NH2 (amine), –COOH (carboxyl), and –CN (cyano) on the structural parameters, global reactivity, aromaticity, and UV-visible spectra of pyrene are studied with the help of density functional theory (DFT). Global reactivity parameters such as global hardness (η) and electrophilicity (ω) are calculated using density functional reactivity theory (DFRT). Time dependent density functional theory (TD-DFT) is explored for interpreting the UV-visible absorption spectra. Aromaticity of the pyrene rings are predicted from the nucleus independent chemical shift (NICS) values. Presence of BN unit and substituent induces reasonable impact on the studied parameters. The observed absorption spectra lie predominantly within the UV-region (both blue and red shifts are observed in presence of BN and substituent). HOMO energy and absorption spectra are affected nominally in solvent phase.

scholarly journals Density Functional Theory Study on the Electronic Structures of Oxadiazole Based Dyes as Photosensitizer for Dye Sensitized Solar Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Umer Mehmood ◽  
Ibnelwaleed A. Hussein ◽  
Khalil Harrabi ◽  
Shakeel Ahmed
Keyword(s):  
Density Functional Theory ◽  
Absorption Spectra ◽  
Density Functional ◽  
Energy Levels ◽  
Dye Sensitized Solar Cells ◽  
Electron Injection ◽  
Molecular Structures ◽  
Visible Absorption ◽  
Functional Theory ◽  
Oxidation Potentials

The molecular structures and UV-visible absorption spectra of complex photosensitizers comprising oxadiazole isomers as theπ-bridges were analyzed by density functional theory (DFT) and time-dependent DFT. The ground state and excited state oxidation potentials, HOMOs and LUMOs energy levels, and electron injection from the dyes to semiconductor TiO2have been computed in vacuum here. The results show that all of the dyes may potentially be good photosensitizers in DSSC. To justify the simulation basis, N3 dye was also simulated under the similar conditions. Simulated absorption spectrum, HOMO, LUMO, and band gap values of N3 were compared with the experimental values. We also computed the electronic structure properties and absorption spectra of dye/(TiO2)8systems to elucidate the electron injection efficiency at the interface. This work is expected to give proper orientation for experimental synthesis.

scholarly journals Optical Absorption and Electron Injection of 4-(Cyanomethyl)benzoic Acid Based Dyes: A DFT Study

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Yuehua Zhang ◽  
Penghui Ren ◽  
Yuanzuo Li ◽  
Runzhou Su ◽  
Meiyu Zhao
Keyword(s):  
Density Functional Theory ◽  
Benzoic Acid ◽  
Density Functional ◽  
Photovoltaic Performance ◽  
Dye Sensitized Solar Cells ◽  
Electron Injection ◽  
Oxidation Potential ◽  
Conduction Band Edge ◽  
Functional Theory ◽  
Sensitized Solar Cells

Density functional theory (DFT) and time-dependent density functional theory (TDDFT) calculations were carried out to study the ground state geometries, electronic structures, and absorption spectra of 4-(cyanomethyl)benzoic acid based dyes (AG1 and AG2) used for dye-sensitized solar cells (DSSCs). The excited states properties and the thermodynamical parameters of electron injection were studied. The results showed that (a) two dyes have uncoplanar structures along the donor unit and conjugated bridge space, (b) two sensitizers exhibited intense absorption in the UV-Vis region, and (c) the excited state oxidation potential was higher than the conduction band edge of TiO2photoanode. As a result, a solar cell based on the 4-(cyanomethyl)benzoic acid based dyes exhibited well photovoltaic performance. Furthermore, nine dyes were designed on the basis of AG1 and AG2 to improve optical response and electron injection.

Computational study on zinc porphyrin analogs for use in dye-sensitized solar cells

2014 ◽  
Vol 18 (05) ◽  
pp. 406-415 ◽  
Author(s):  
Hong-Qiang Xia ◽  
Jie Chen ◽  
Fu-Quan Bai ◽  
Hong-Xing Zhang
Keyword(s):  
Absorption Spectra ◽  
Density Functional ◽  
Computational Study ◽  
Dye Sensitized Solar Cells ◽  
Absorption Enhancement ◽  
Zinc Porphyrin ◽  
The Density Functional Theory ◽  
Td Dft ◽  
Sensitized Solar Cells ◽  
Porphyrin Analogs

The density functional theory (DFT) and time-dependent DFT (TD-DFT) approaches have been applied to obtain the optimized geometries, electronic structures, molecular orbitals and absorption spectra of a series of meso-substituted zinc porphyrin analogs with phenyl and thiophene groups as the π bridging unit and cyanoacrylic acid as the acceptor unit. The results showed that the introduction of thiophene group increases the orbital splitting and changes the absorption spectra properties significantly. It is indicated that when there is only one thiophene group included in the π bridge, the oscillator strength of B absorption band is much stronger. The increasing length of thiophene chain just changes the scope of specific absorption enhancement. The effect of attaching an additional electron-donating group diphenylamine instead of phenyl to the porphyrin core also has been shown. It is found that the diphenylamine group reduces the band gap, and leads to facile intramolecular charge transfer from diphenylamine and porphyrin ring unit to acceptor unit. These kinds of zinc porphyrin analogs have the LUMO energy close to the conduction band of TiO 2 and more red-shifted absorption spectrum compared with phenyl substituted analogs.

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