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.

Wechselwirkungen in Molekülkristallen, 166 [1, 2]. Polyiod-Moleküle I2C=CI2, (IC)4S, (IC)4NH, (IC)4N-CH3 und HCI3: Strukturbestimmung nach Kristallzüchtung oder durch Dichtefunktionaltheorie-Berechnung / Interaction in Molecular Crystals, 166 [1, 2], Polyiodo Molecules I2C=CI2, (IC)4S, (IC)4 NH, (IC)4N-CH and HCI3: Structure Determination Following Crystallization or by Density Functional Theory Calculation

2001 ◽  
Vol 56 (1) ◽  
pp. 13-24 ◽  
Author(s):  
Hans Bock ◽  
Sven Holl ◽  
Volker Krenzel
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Crystal Packing ◽  
Density Functional Theory Calculation ◽  
Density Functional Theory Calculations ◽  
Structural Data ◽  
Basis Sets ◽  
Functional Theory ◽  
Donor Acceptor ◽  
Density Functional Theory Optimization

Abstract The structures of tri-and tetraiodo-substituted carbon compounds are determined either expe­rimentally by X-Ray Structure Analysis or, because crystallization of tetraiodothiophene could not be achieved, approximated by Density Functional Theory optimization of structural data from a donor/acceptor complex. The structures show noteworthy details such as a second po­lymorph of tetraiodoethene crystallized by sublimation or herringbone crystal packing patterns of tetraiodopyrrole derivatives. All molecular geometries are discussed and compared based on relativistic density functional theory calculations with 6 -31G* basis sets including iodine pseudopotentials. They reproduce even finer structural details due to van der Waals repulsion of the bulky iodo substituents. Natural Bond Orbital (NBO) charge distributions suggest positive partial charges at all iodine centers with the strongest polarization Cδ㊀ → Iδ㊉ in HCI3, which contains well over 97% iodine.

scholarly journals Star-shaped and linear π-conjugated oligomers consisting of a tetrathienoanthracene core and multiple diketopyrrolopyrrole arms for organic solar cells

2016 ◽  
Vol 12 ◽  
pp. 1459-1466 ◽  
Author(s):  
Hideaki Komiyama ◽  
Chihaya Adachi ◽  
Takuma Yasuda
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Fullerene Derivative ◽  
Conjugated Oligomers ◽  
Visible Absorption ◽  
Photovoltaic Properties ◽  
Wide Range ◽  
Visible Wavelengths

Solution-processable star-shaped and linear π-conjugated oligomers consisting of an electron-donating tetrathienoanthracene (TTA) core and electron-accepting diketopyrrolopyrrole (DPP) arms, namely, TTA-DPP4 and TTA-DPP2, were designed and synthesized. Based on density functional theory calculations, the star-shaped TTA-DPP4 has a larger oscillator strength than the linear TTA-DPP2, and consequently, better photoabsorption property over a wide range of visible wavelengths. The photovoltaic properties of organic solar cells based on TTA-DPP4 and TTA-DPP2 with a fullerene derivative were evaluated by varying the thickness of the bulk heterojunction active layer. As a result of the enhanced visible absorption properties of the star-shaped π-conjugated structure, better photovoltaic performances were obtained with relatively thin active layers (40–60 nm).

On the dissolution of lithium sulfate in water: anion photoelectron spectroscopy and density functional theory calculations

2015 ◽  
Vol 17 (8) ◽  
pp. 5624-5631 ◽  
Author(s):  
Gang Feng ◽  
Gao-Lei Hou ◽  
Hong-Guang Xu ◽  
Zhen Zeng ◽  
Wei-Jun Zheng
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Photoelectron Spectroscopy ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Lithium Sulfate ◽  
Functional Theory ◽  
Anion Photoelectron Spectroscopy ◽  
Insight Into

Microscopic insight into the dissolution of Li2SO4in water was gained using photoelectron spectroscopy combined with DFT calculations.

scholarly journals The Role of Structural Flexibility in Plasmon-Driven Coupling Reactions: Kinetic Limitations in the Dimerization of Nitro-Benzenes

2021 ◽  
Author(s):  
Wouter Koopman ◽  
Evgenii Titov ◽  
Radwan Mohamed Sarhan ◽  
Tina Gaebel ◽  
Robin Schürmann ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Photoelectron Spectroscopy ◽  
Density Functional ◽  
Bond Activation ◽  
Density Functional Theory Calculations ◽  
Surface Enhanced Raman Spectroscopy ◽  
Bimolecular Reaction ◽  
Structural Flexibility ◽  
Coupling Reactions ◽  
Time Resolved

<div>The plasmon-driven dimerization of 4-nitrothiophenol (4NTP) to 4-4’-dimercaptoazobenzene (DMAB) has become a testbed for understanding bimolecular photoreactions enhanced by nanoscale metals, in particular, regarding the relevance of electron transfer and heat transfer from the metal to the molecule. By adding a methylene group between the thiol bond and the nitrophenyl, we add structural flexibility to the reactant molecule. Time-resolved surface-enhanced Raman-spectroscopy proves that this (4-nitrobenzyl)mercaptan (4NBM) molecule has a larger dimerization rate and dimerization yield than 4NTP and higher selectivity towards dimerization. X-ray photoelectron spectroscopy and density functional theory calculations show that the electron transfer would prefer activation of 4NTP over 4NBM. We conclude that the rate limiting step of this plasmonic reaction is the dimerization step, which is dramatically enhanced by the additional flexibility of the reactant. This study may serve as an example for using nanoscale metals to simultaneously provide charge carriers for bond activation and localized heat for driving bimolecular reaction steps. The molecular structure of reactants can be tuned to control the reaction kinetics.<br></div>

scholarly journals Electronic and vibrational decoupling in chemically exfoliated bilayer 2D-V2O5

2021 ◽  
Author(s):  
Reshma P R ◽  
Anees Pazhedath ◽  
Ganesan Karuppiah ◽  
Arun Prasad ◽  
Sandip Dhara
Keyword(s):  
Transition Metal ◽  
Photoelectron Spectroscopy ◽  
Density Functional ◽  
Blue Shift ◽  
X Ray Diffraction ◽  
Phonon Modes ◽  
Visible Absorption ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force

Abstract Recently emerged transition metal oxide (TMO) based 2D nanostructures are gaining a foothold in advanced applications. Unlike, 2D transition metal dichalchogenides, it is strenuous to obtain high quality thin TMOs due to exotic surface reconstruction during synthesis. Herein, we report the synthesis of bilayer thin 2D-V2O5 nanosheets using chemical exfoliation. Synchrotron X-ray diffraction, X-ray photoelectron spectroscopy and atomic force microscopy substantiate the successful formation of bilayer thin 2D-V2O5. Ultraviolet-visible absorption spectra exhibit a thickness dependent blue shift in the optical band gap, signifying the emergence of electronic decoupling. Raman spectroscopy fingerprinting shows a thickness dependent vibrational decoupling of phonon modes. Further, it has been verified by computing the lattice vibrational modes using density functional perturbation theory. In this study, the manifestation of the electronic and vibrational decoupling is used as a novel probe to confirm the successful exfoliation of bilayer 2D-V2O5 from its bulk counterpart.

scholarly journals Resonant Ta Doping for Enhanced Mobility in Transparent Conducting SnO2

2019 ◽  
Author(s):  
Benjamin Williamson ◽  
Thomas Featherstone ◽  
Sanjayan Sathasivam ◽  
Jack Swallow ◽  
Huw Shiel ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Consumer Electronics ◽  
Electron Effective Mass ◽  
Conducting Oxides ◽  
Transparent Conducting ◽  
Earth Abundant ◽  
Sb Doping

<div>Transparent conducting oxides (TCOs) are ubiquitous in modern consumer electronics. SnO<sub>2</sub> is an earth abundant, cheaper alternative to In<sub>2</sub>O<sub>3</sub> as a TCO however, its performance in terms of electrical properties lags behind that of In<sub>2</sub>O<sub>3</sub>. Based on the recent discovery of mobility and conductivity enhancements in In<sub>2</sub>O<sub>3</sub> from resonant dopants, we use a combination of state-of-the-art hybrid density functional theory calculations, high resolution photoelectron spectroscopy and semiconductor statistics modelling to understand what the optimal dopant is to maximise performance of SnO<sub>2</sub>-based TCOs. We demonstrate that Ta is the optimal dopant for high performance SnO<sub>2</sub>, as it is a resonant dopant which is readily incorporated into SnO<sub>2</sub> with the Ta 5d states sitting ~1.4 eV above the conduction band minimum. Experimentally, the electron effective mass of Ta doped SnO<sub>2</sub> was shown to be 0.23m<sub>0</sub>, compared to 0.29m<sub>0</sub> seen with conventional Sb doping, explaining its ability to yield higher mobilities and conductivities.</div><div><br></div>

scholarly journals Resonant Ta Doping for Enhanced Mobility in Transparent Conducting SnO2

2019 ◽  
Author(s):  
Benjamin Williamson ◽  
Thomas Featherstone ◽  
Sanjayan Sathasivam ◽  
Jack Swallow ◽  
Huw Shiel ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Consumer Electronics ◽  
Electron Effective Mass ◽  
Conducting Oxides ◽  
Transparent Conducting ◽  
Earth Abundant ◽  
Sb Doping

<div>Transparent conducting oxides (TCOs) are ubiquitous in modern consumer electronics. SnO<sub>2</sub> is an earth abundant, cheaper alternative to In<sub>2</sub>O<sub>3</sub> as a TCO however, its performance in terms of electrical properties lags behind that of In<sub>2</sub>O<sub>3</sub>. Based on the recent discovery of mobility and conductivity enhancements in In<sub>2</sub>O<sub>3</sub> from resonant dopants, we use a combination of state-of-the-art hybrid density functional theory calculations, high resolution photoelectron spectroscopy and semiconductor statistics modelling to understand what the optimal dopant is to maximise performance of SnO<sub>2</sub>-based TCOs. We demonstrate that Ta is the optimal dopant for high performance SnO<sub>2</sub>, as it is a resonant dopant which is readily incorporated into SnO<sub>2</sub> with the Ta 5d states sitting ~1.4 eV above the conduction band minimum. Experimentally, the electron effective mass of Ta doped SnO<sub>2</sub> was shown to be 0.23m<sub>0</sub>, compared to 0.29m<sub>0</sub> seen with conventional Sb doping, explaining its ability to yield higher mobilities and conductivities.</div><div><br></div>

Sign in / Sign up

Export Citation Format

Share Document