Characterization of the structural, mechanical, and electronic properties of fullerene mixtures: a molecular simulations description

2018 ◽  
Vol 6 (14) ◽  
pp. 3642-3650 ◽  
Author(s):  
Naga Rajesh Tummala ◽  
Saadullah G. Aziz ◽  
Veaceslav Coropceanu ◽  
Jean-Luc Bredas
Keyword(s):  
Molecular Dynamics ◽  
Density Functional Theory ◽  
Solar Cells ◽  
Electronic Properties ◽  
Organic Solar Cells ◽  
Density Functional ◽  
Molecular Simulations ◽  
Functional Theory ◽  
Fullerene Derivatives

We investigate mixtures of fullerenes and fullerene derivatives, the most commonly used electron accepting materials in organic solar cells, by using a combination of molecular dynamics and density functional theory methods.

Density-Functional Theory Molecular Dynamics Simulations and Experimental Characterization of a-Al2O3/SiGe Interfaces

2015 ◽  
Vol 7 (47) ◽  
pp. 26275-26283 ◽  
Author(s):  
Evgueni Chagarov ◽  
Kasra Sardashti ◽  
Tobin Kaufman-Osborn ◽  
Shailesh Madisetti ◽  
Serge Oktyabrsky ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Density Functional Theory ◽  
Molecular Dynamics Simulations ◽  
Density Functional ◽  
Experimental Characterization ◽  
Functional Theory ◽  
Dynamics Simulations

Design and characteration of planar star-shaped oligomer electron donors for organic solar cells: a DFT study

2015 ◽  
Vol 93 (11) ◽  
pp. 1181-1190 ◽  
Author(s):  
Dongmei Wang ◽  
Zhiyuan Geng
Keyword(s):  
Density Functional Theory ◽  
Solar Cells ◽  
Charge Transfer ◽  
Energy Level ◽  
Organic Solar Cells ◽  
Density Functional ◽  
Short Circuit ◽  
Frontier Molecular Orbital ◽  
Orbital Energy ◽  
Functional Theory

To seek high-performance oligomer donor materials used in organic solar cells, four star-shaped molecules with a planar donor core derived from the recent reported molecule 3T-P-DPP (phenyl-1,3,5-trithienyl-diketopyrrolopyrrole) were designed. The molecular properties affecting the cell performance, such as structural characteristics, frontier molecular orbital energy level, absorption spectra, exciton character, and charge transfer/transport, were investigated by means of the density functional theory and time-dependent density functional theory methods. Comparative analysis showed that the new designed molecule 3 with a TTT (2,4,6-tri(thiophen-2-yl)-1,3,5-triazine) core has better planarity, a lower HOMO energy level, and a higher absorption efficiency, as well as more favorable exciton dissociation and charge transfer than the others, potentially improving the open-circuit voltage and short-circuit current density. Consequently, 3 maybe superior to 3T-P-DPP and may act as a promising donor material candidate for organic solar cells.

scholarly journals Molecular engineering of indenoindene-3-ethylrodanine acceptors with A2-A1-D-A1-A2 architecture for promising fullerene-free organic solar cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Muhammad Khalid ◽  
Momina ◽  
Muhammad Imran ◽  
Muhammad Fayyaz ur Rehman ◽  
Ataualpa Albert Carmo Braga ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Solar Cells ◽  
Charge Transfer ◽  
Organic Solar Cells ◽  
Density Functional ◽  
Energy Gap ◽  
Molecular Engineering ◽  
Frontier Molecular Orbital ◽  
Functional Theory ◽  
Acceptor Molecules

AbstractConsidering the increased demand and potential of photovoltaic devices in clean, renewable electrical and hi-tech applications, non-fullerene acceptor (NFA) chromophores have gained significant attention. Herein, six novel NFA molecules IBRD1–IBRD6 have been designed by structural modification of the terminal moieties from experimentally synthesized A2-A1-D-A1-A2 architecture IBR for better integration in organic solar cells (OSCs). To exploit the electronic, photophysical and photovoltaic behavior, density functional theory/time dependent-density functional theory (DFT/TD-DFT) computations were performed at M06/6-311G(d,p) functional. The geometry, electrical and optical properties of the designed acceptor molecules were compared with reported IBR architecture. Interestingly, a reduction in bandgap (2.528–2.126 eV), with a broader absorption spectrum, was studied in IBR derivatives (2.734 eV). Additionally, frontier molecular orbital findings revealed an excellent transfer of charge from donor to terminal acceptors and the central indenoindene-core was considered responsible for the charge transfer. Among all the chromophores, IBRD3 manifested the lowest energy gap (2.126 eV) with higher λmax at 734 and 745 nm in gaseous phase and solvent (chloroform), respectively due to the strong electron-withdrawing effect of five end-capped cyano groups present on the terminal acceptor. The transition density matrix map revealed an excellent charge transfer from donor to terminal acceptors. Further, to investigate the charge transfer and open-circuit voltage (Voc), PBDBT donor polymer was blended with acceptor chromophores, and a significant Voc (0.696–1.854 V) was observed. Intriguingly, all compounds exhibited lower reorganization and binding energy with a higher exciton dissociation in an excited state. This investigation indicates that these designed chromophores can serve as excellent electron acceptor molecules in organic solar cells (OSCs) that make them attractive candidates for the development of scalable and inexpensive optoelectronic devices.

scholarly journals Molecular dynamics with constrained nuclear electronic orbital density functional theory: Accurate vibrational spectra from efficient incorporation of nuclear quantum effects

2021 ◽  
Author(s):  
Xi Xu ◽  
Zehua Chen ◽  
Yang Yang
Keyword(s):  
Molecular Dynamics ◽  
Density Functional Theory ◽  
Vibrational Spectra ◽  
Density Functional ◽  
Molecular Simulations ◽  
Quantum Effects ◽  
Functional Theory ◽  
Chemical And Biological Systems ◽  
Nuclear Quantum Effects ◽  
Orbital Density

Nuclear quantum effects play a crucial role in many chemical and biological systems involving hydrogen atoms yet are difficult to include in practical molecular simulations. In this Letter, we combine our recently developed methods of constrained nuclear-electronic orbital density functional theory (cNEO-DFT) and constrained minimized energy surface molecular dynamics (CMES-MD) to create a new method for accurately and efficiently describing nuclear quantum effects in molecular simulations. Using this new method, dubbed cNEO-MD, the vibrational spectra of a set of small molecules are calculated and compared with those from conventional ab initio molecular dynamics (AIMD) as well as from experiments. With the same formal scaling, cNEO-MD greatly outperforms AIMD in describing the vibrational modes with significant hydrogen motion characters, demonstrating the promise of cNEO-MD for simulating chemical and biological systems with significant nuclear quantum effects.

scholarly journals Exploration of promising optical and electronic properties of (non-polymer) small donor molecules for organic solar cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Muhammad Khalid ◽  
Muhammad Usman Khan ◽  
Saeed Ahmed ◽  
Zahid Shafiq ◽  
Mohammed Mujahid Alam ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Solar Cells ◽  
Organic Solar Cells ◽  
Density Functional ◽  
Reorganization Energy ◽  
Energy Difference ◽  
Open Circuit ◽  
Frontier Molecular Orbital ◽  
Functional Theory ◽  
Td Dft

AbstractNon-fullerene based organic compounds are considered promising materials for the fabrication of modern photovoltaic materials. Non-fullerene-based organic solar cells comprise of good photochemical and thermal stability along with longer device lifetimes as compared to fullerene-based compounds. Five new non-fullerene donor molecules were designed keeping in view the excellent donor properties of 3-bis(4-(2-ethylhexyl)-thiophen-2-yl)-5,7-bis(2ethylhexyl) benzo[1,2-:4,5-c′]-dithiophene-4,8-dione thiophene-alkoxy benzene-thiophene indenedione (BDD-IN) by end-capped modifications. Photovoltaic and electronic characteristics of studied molecules were determined by employing density functional theory (DFT) and time dependent density functional theory (TD-DFT). Subsequently, obtained results were compared with the reference molecule BDD-IN. The designed molecules presented lower energy difference (ΔΕ) in the range of 2.17–2.39 eV in comparison to BDD-IN (= 2.72 eV). Moreover, insight from the frontier molecular orbital (FMO) analysis disclosed that central acceptors are responsible for the charge transformation. The designed molecules were found with higher λmax values and lower transition energies than BDD-IN molecule due to stronger end-capped acceptors. Open circuit voltage (Voc) was observed in the higher range (1.54–1.78 V) in accordance with HOMOdonor–LUMOPC61BM by designed compounds when compared with BDD-IN (1.28 V). Similarly, lower reorganization energy values were exhibited by the designed compounds in the range of λe(0.00285–0.00370 Eh) and λh(0.00847–0.00802 Eh) than BDD-IN [λe(0.00700 Eh) and λh(0.00889 Eh)]. These measurements show that the designed compounds are promising candidates for incorporation into solar cell devices, which would benefit from better hole and electron mobility.

scholarly journals Characterization of β-turns by electronic circular dichroism spectroscopy: a coupled molecular dynamics and time-dependent density functional theory computational study

2020 ◽  
Vol 22 (3) ◽  
pp. 1611-1623
Author(s):  
Mattia Migliore ◽  
Andrea Bonvicini ◽  
Vincent Tognetti ◽  
Laure Guilhaudis ◽  
Marc Baaden ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Density Functional Theory ◽  
Molecular Dynamics Simulations ◽  
Density Functional ◽  
Computational Study ◽  
Time Dependent ◽  
Functional Theory ◽  
Dynamics Simulations ◽  
Dependent Density

TDDFT coupled with molecular dynamics simulations are used for β-turn characterization by ECD spectroscopy.

Sign in / Sign up

Export Citation Format

Share Document