scholarly journals Understanding the Electronic Interactions, Vertical Excitation Analysis, and the Photovoltaic Properties of 5-(2-ethylhexyl)-1,3-di(furan-2-yl)-4H-thieno[3,4-c]pyrrole-4,6-dione

2021 ◽  
Author(s):  
Obieze Christian Enudi ◽  
Hitler Louis ◽  
Goodness J. Ogunwale ◽  
Michael T. Kadiri ◽  
Prince M. Okibe ◽  
...  
Keyword(s):  
Density Functional ◽  
Low Cost ◽  
Volume Ratio ◽  
Theoretical Method ◽  
Electron Excitation ◽  
Photovoltaic Properties ◽  
Vertical Excitation ◽  
Singlet States ◽  
Donor Acceptor ◽  
Conversion Efficiencies

Abstract Organic photovoltaic (OPV) are a promising new class of photovoltaic as they offer several advantageous features including large surface area to volume ratio, low cost, lightweight properties, and durability. The limitation of OPV that prevented their adoption for use in the past was their low power conversion efficiency (PCE) but that drawback has been solved by the development of the donor-acceptor-donor (D-A-D) system with high conversion efficiencies. Herein, 5-(2-ethylhexyl)-1,3-di (furan-2-yl)-4H-thieno [3,4-c]pyrrole-4,6(5H)-dione (FTPF), a donor-acceptor-donor monomer was investigated for its optoelectronic, excited state, and photovoltaic properties using a density functional theory (DFT) and time-dependent density function theory (TD-DFT) at the B3LYP/6-31+G(d,p) theoretical method. The spectral analysis (FT-IR, UV-vis, and NMR), electronic molecular properties, natural bonding orbitals (MOs and NBOs) analyses, and excitation were studied at this level in gas, hexane, DMF, and THF. The UV-Vis spectrum showed that FTPF exhibited mono-absorption in non-polar gas and hexane, but dual absorptions in polar solvents (DMF and THF) having maximum wavelength (λmax) at 351, 359, 371 and 373 nm in gas, hexane, THF, and DMF respectively, showing a major red shift as solvent became polar. The hole-electron excitation studies of the first five singlet states: S0→S1/S2/S3/S4/S5 in gas and DMF phases showed that S0→S1 is a delocalized π→π* Rydberg excitations originating from the D-A-D C=C π bonds, S0→S2 is π→π* local excitation, while S0→S3 in water occurred as an n→π* from the carbonyl and azolide groups of the acceptor unit, but n→π* charge transfer (CT) in DMF. The S0→S5 in water and S0→S4 are n→π* LE type excitations, while S0→S5 in DMF conformed to a delocalized π→π* excitation extended over the D-A-D conjugated backbone. FTPF provided efficient electron injection in all studied solvent; showing that FTPF is a sure-bet for opto-electronic application.

scholarly journals Performance of Natural Dye Extracted from Annatto, Black Plum, Turmeric, Red Spinach, and Cactus as Photosensitizers in TiO2NP/TiNT Composites for Solar Cell Applications

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Shibu Joseph ◽  
Albin John P. Paul Winston ◽  
S. Muthupandi ◽  
P. Shobha ◽  
S. Mary Margaret ◽  
...  
Keyword(s):  
Solar Cell ◽  
Low Cost ◽  
Short Circuit ◽  
Dye Sensitized Solar Cells ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Photovoltaic Properties ◽  
Ft Ir ◽  
Conversion Efficiencies ◽  
Sensitized Solar Cells

This paper is aimed at how to select, extract, and characterize natural dyes and to use them as sensitizers in dye-sensitized solar cells (DSSCs). Dyes obtained from fresh sources of annatto fruits, black plums, cactus fruits, turmeric roots, and red spinach leaves were used as sensitizers. The dye pigments were analyzed using UV-Vis spectrophotometer and FT-IR for the characterization of their spectral properties. The combination from Titanium dioxide paste with the powdered nanotubes was used as photoanodes for DSSCs. The photovoltaic properties of the DSSCs such as efficiency, fill factor, open-circuit voltage, and short circuit current were studied using a standard illumination of air-mass 1.5 global (AM 1.5 G) having an irradiance of 100 mW/cm2. The highest power conversion efficiencies (η) of 0.7% was achieved for the DSSCs fabricated using dye extracted from annatto fruits and 0.4% each for dyes extracted from black plum fruits and cactus fruits, respectively. The widespread accessibility of these fruits, roots, and leaves and ease of extraction of dyes from these ordinarily available natural resources render them unique and low-cost candidates for solar cell fabrication.

An Alternating Donor–Acceptor Conjugated Polymer Based on Benzodithiophene and [3,4-c]pyrrole-4,6-dione: Synthesis, Characterization, and Application in Photovoltaic Devices

2015 ◽  
Vol 68 (11) ◽  
pp. 1773 ◽  
Author(s):  
Erika Bicciocchi ◽  
Matthias Haeussler ◽  
Ezio Rizzardo ◽  
Andrew D. Scully ◽  
Kenneth P. Ghiggino
Keyword(s):  
Photoelectron Spectroscopy ◽  
Conjugated Polymer ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Photovoltaic Devices ◽  
Contributing Factors ◽  
Visible Absorption ◽  
Concomitant Reduction ◽  
Donor Acceptor ◽  
Conversion Efficiencies

The synthesis is described of a new alternating donor–acceptor semiconducting polymer based on an N-octylthieno[3,4-c]pyrrole-4,6-dione building block together with a newly designed 2,3-bis(2-ethylhexyl)thiophenylethynyl substituted benzodithiophene (BDT). The introduction of electron-rich thiophene units to BDT raises the highest occupied molecular orbital (HOMO) level of the conjugated polymer and the concomitant reduction of the bandgap enhances the harvesting of solar radiation. This modification also introduces less sterically demanding triple bonds, thereby potentially enabling more favourable molecular interactions and an extra dimension of conjugation perpendicular to the main polymer chain. The optoelectronic properties of this new conjugated polymer were evaluated using UV-visible absorption and fluorescence spectroscopy, photoelectron spectroscopy in air, photo-induced charge extraction by linearly increasing voltage (Photo-CELIV), and density functional theory calculations. The polymer absorbs broadly in the wavelength range 300–700 nm in solution and the solid state. The estimated HOMO and LUMO levels of −5.4 and −3.6 eV, respectively, correspond to a bandgap of 1.8 eV. Photovoltaic devices fabricated using the polymer as the active layer displayed power conversion efficiencies (PCEs) of up to 1 %. Photo-CELIV results provide evidence that rapid recombination and poor charge mobility are likely contributing factors to the relatively low PCE values observed.

scholarly journals Fluorescent Probe for Simultaneous Detection of Human Serum Albumin and Sulfur Dioxide: A Theoretical Analysis

2021 ◽  
Author(s):  
ang jia ◽  
he huang ◽  
zhong-fu zuo ◽  
xuezheng liu ◽  
Yongjin Peng
Keyword(s):  
Density Functional ◽  
Simultaneous Detection ◽  
Optical Excitation ◽  
Theoretical Method ◽  
Underlying Mechanism ◽  
Electron Excitation ◽  
Synergistic Action ◽  
Functional Theory ◽  
Hydrophobic Cavity ◽  
Theoretical Results

A small molecule probe for simultaneous detection of HSA and SO2 via their distinct fluorescent signals was designed recently. This effective tool provided a significant boost in understand underlying mechanism of synergistic action between SO2 and HSA in disease. The structure and fluorescent character of this probe molecule were studied under density functional theory in this work. The different stable conformations of probe C23 were found through theoretical method which explained the no experimental fluorescent character of the probe itself. The electron excitation analysis indicated the charge transfer process in the restricted C23 (binding to the hydrophobic cavity of HSA) and CS (C23 reaction with SO2) when the molecules were under optical excitation. The theoretical results could be helpful for understanding the electronical properties in the probe and providing the insights for designing new probe molecules.

2,2’-Dipyridylamine as Organic Molecular Electrocatalyst for Hydrogen Evolution Reaction in Acidic Electrolytes

2019 ◽  
Author(s):  
Xi Yin ◽  
Ling Lin ◽  
Hoon T. Chung ◽  
Ulises Martinez ◽  
Andrew M. Baker ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Density Functional ◽  
Low Cost ◽  
Membrane Electrode Assembly ◽  
Carbon Surface ◽  
Membrane Electrode ◽  
Durability Test ◽  
Onset Potential ◽  
Precious Metal Catalysts

Finding a low-cost and stable electrocatalyst for hydrogen evolution reaction (HER) as a replacement for scarce and expensive precious metal catalysts has attracted significant interest from chemical and materials research communities. Here, we demonstrate an organic catalyst based on 2,2’-dipyridylamine (dpa) molecules adsorbed on carbon surface, which shows remarkable hydrogen evolution activity and performance durability in strongly acidic polymer electrolytes without involving any metal. The HER onset potential at dpa adsorbed on carbon has been found to be less than 50 mV in sulfuric acid and in a Nafion-based membrane electrode assembly (MEA). At the same time, this catalyst has shown no performance loss in a 60-hour durability test. The HER reaction mechanisms and the low onset overpotential in this system are revealed based on electrochemical study. Density functional theory (DFT) calculations suggest that the pyridyl-N functions as the active site for H adsorption with a free energy of -0.13 eV, in agreement with the unusually low onset overpotential for an organic molecular catalyst.<br>

2,2’-Dipyridylamine as Organic Molecular Electrocatalyst for Hydrogen Evolution Reaction in Acidic Electrolytes

2019 ◽  
Author(s):  
Xi Yin ◽  
Ling Lin ◽  
Hoon T. Chung ◽  
Ulises Martinez ◽  
Andrew M. Baker ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Density Functional ◽  
Low Cost ◽  
Membrane Electrode Assembly ◽  
Carbon Surface ◽  
Membrane Electrode ◽  
Durability Test ◽  
Onset Potential ◽  
Precious Metal Catalysts

Finding a low-cost and stable electrocatalyst for hydrogen evolution reaction (HER) as a replacement for scarce and expensive precious metal catalysts has attracted significant interest from chemical and materials research communities. Here, we demonstrate an organic catalyst based on 2,2’-dipyridylamine (dpa) molecules adsorbed on carbon surface, which shows remarkable hydrogen evolution activity and performance durability in strongly acidic polymer electrolytes without involving any metal. The HER onset potential at dpa adsorbed on carbon has been found to be less than 50 mV in sulfuric acid and in a Nafion-based membrane electrode assembly (MEA). At the same time, this catalyst has shown no performance loss in a 60-hour durability test. The HER reaction mechanisms and the low onset overpotential in this system are revealed based on electrochemical study. Density functional theory (DFT) calculations suggest that the pyridyl-N functions as the active site for H adsorption with a free energy of -0.13 eV, in agreement with the unusually low onset overpotential for an organic molecular catalyst.<br>

scholarly journals Completely non-fused electron acceptor with 3D-interpenetrated crystalline structure enables efficient and stable organic solar cell

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Lijiao Ma ◽  
Shaoqing Zhang ◽  
Jincheng Zhu ◽  
Jingwen Wang ◽  
Junzhen Ren ◽  
...  
Keyword(s):  
Organic Solar Cell ◽  
Low Cost ◽  
Three Dimensional ◽  
Molecular Geometry ◽  
Interpenetrating Network ◽  
Fused Ring ◽  
Molecule Design ◽  
End Capping ◽  
Conversion Efficiencies ◽  
Insight Into

AbstractNon-fullerene acceptors (NFAs) based on non-fused conjugated structures have more potential to realize low-cost organic photovoltaic (OPV) cells. However, their power conversion efficiencies (PCEs) are much lower than those of the fused-ring NFAs. Herein, a new bithiophene-based non-fused core (TT-Pi) featuring good planarity as well as large steric hindrance was designed, based on which a completely non-fused NFA, A4T-16, was developed. The single-crystal result of A4T-16 reveals that a three-dimensional interpenetrating network can be formed due to the compact π–π stacking between the adjacent end-capping groups. A high PCE of 15.2% is achieved based on PBDB-TF:A4T-16, which is the highest value for the cells based on the non-fused NFAs. Notably, the device retains ~84% of its initial PCE after 1300 h under the simulated AM 1.5 G illumination (100 mW cm−2). Overall, this work provides insight into molecule design of the non-fused NFAs from the aspect of molecular geometry control.

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.

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