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).

14.7% all-small-molecule organic solar cells enabled with fullerene derivative incorporation

2021 ◽  
Author(s):  
Hu Dingqin ◽  
Hua Tang ◽  
Haiyan Chen ◽  
Jie Lv ◽  
Shirong Lu ◽  
...  
Keyword(s):  
Solar Cells ◽  
Small Molecule ◽  
Organic Solar Cells ◽  
Fullerene Derivative ◽  
Photovoltaic Properties

Ternary strategy is promising to enhance the photovoltaic properties of organic solar cells (OSCs). Nevertheless, it is full of challenging when this approach involving only small molecule. Herein, a fullerene...

scholarly journals Designing and Theoretical study of fluorinated small molecule donor materials for organic solar cells

2021 ◽  
Author(s):  
Usama Mubashar ◽  
Afifa Farhat ◽  
Rasheed Ahmad Khera ◽  
Rabia Saleem ◽  
Javed IQBAL
Keyword(s):  
Band Gap ◽  
Organic Solar Cells ◽  
Density Functional ◽  
Optical Band Gap ◽  
Transition Density ◽  
Reorganization Energy ◽  
Binding Energies ◽  
Fullerene Derivative ◽  
Photovoltaic Properties ◽  
Enhanced Absorption

Abstract A recently synthesized photoactive donor named fluorinated thienyl substituted benzodithiophene (DRTB-FT), modified with four novel end capped acceptor molecules, have been investigated through different electrical, quantum and spectrochemical techniques for their enhanced electro-optical and photovoltaic properties. DRTB-FT was connected to 2-methylenemalononitrile (D-1), 2-methylene-3-oxobutanenitrile (D-2), 2-(2-methylene-3-oxo-2,3-dihydro-1H-inden-1-ylidene) malonitrile (D-3) and 3-methyl-5methylene-2-thioxothiazolidin-4-one (D-4) as terminal acceptor moieties. The architectural D-1 and D-3 molecules owe reduced optical band gap of 2.45 and 2.28 eV benefited from A-D-A configuration and have broaden maximum absorption band (λmax) at 617 and 602 nm in polar organic solvent (chloroform). Reduced optical band gap set the ease for enhanced absorption. Reorganization energy of electron (λe) of D-3 molecule (0.00397 eV) was smaller amongst all which disclosed its greater mobility of conducting electrons (ICT). Larger values of dipole moment (µ) of D-1(5.939 Debye) and D-3 (3.661 Debye) molecules in comparison to R indicated greater solubilities of the targeted molecules. Among the tailored molecules, D-3 showed lowest binding energy of 0.25 eV in solvent phase and 0.08 eV in gaseous phase. The voltaic strength of designed molecules was examined with respect to fullerene derivative (PC61BM) which exposed that D-1 is the best choice for achieving higher PCE. TDM (transition density matrix), DOS (density of states) analysis and binding energies all were estimated at MPW1PW91/6-31G (d, p) level of DFT (density functional theory).

Theoretical, spectroscopical, and experimental investigations of small azomethine molecules for organic solar cells

2020 ◽  
Vol 44 (9-10) ◽  
pp. 625-631
Author(s):  
Cigdem Yorur Goreci
Keyword(s):  
Solar Cells ◽  
Molecular Orbital ◽  
Organic Solar Cells ◽  
Density Functional ◽  
Diphenyl Ether ◽  
Photovoltaic Performance ◽  
Acid Methyl Ester ◽  
Density Functional Theory Calculations ◽  
Experimental Investigations ◽  
Potential Surfaces

Small azomethine molecules ( 4,4′-bis((2-hydroxy-4-octyloxyphenyl)methylimino)diphenylmethane (BP-DPM) and 4,4′-bis((2-hydroxy-4-octyloxyphenyl)methylimino)diphenyl ether (BP-DPE)) for photovoltaic applications were synthesized by condensation of appropriate arylaldehydes and arylendiamines and characterized using Fourier-transform infrared spectroscopy, 1H NMR, 13C NMR, and liquid chromatography–mass spectrometry. Azomethine molecules are additives in organic solar cells. The effect of a possible energy transfer between BP-DPE and P3HT on the photovoltaic performance of devices employing ternary blends of BP-DPE:P3HT: phenyl-C61-butyric acid methyl ester (PCBM) was investigated by absorption and emission spectra. The devices employing BP-DPE:P3HT:PCBM with 1:4 ratio exhibited a Jsc of 4.2 mA cm−2, Voc of 575 mV, and FF of 0.27 which led to a power conversion efficiency (PCE) of 0.65%. In addition, density functional theory calculations (DFT/B3LYP/6-31G(d)) were used to determine the optimized molecular geometry, highest occupied molecular orbital–lowest unoccupied molecular orbital energies, electronic structures, and the molecular electrostatic potential surfaces of the molecules.

scholarly journals Efficient Molecular Modelling of Butterfly-Shaped Hole Transport Materials With Remarkable Photovoltaic Properties For High-Performance Organic Solar Cells

2021 ◽  
Author(s):  
Muhammad Yasir Mehboob ◽  
Muhammad Adnan ◽  
Riaz Hussain ◽  
Zobia Irshad
Keyword(s):  
Solar Cells ◽  
Density Of States ◽  
Organic Solar Cells ◽  
Density Functional ◽  
Transition Density ◽  
Open Circuit ◽  
Hole Transport ◽  
Excitation Energies ◽  
Strong Electron ◽  
Photovoltaic Properties

Abstract Currently, organic solar cells (OSCs) with non-fullerene electron acceptors offer the highest efficiencies among all reported OSCs. To further improve the efficiencies and stabilities of fullerene-free organic solar cells, end-capped acceptor variations is built with strong electron withdrawing groups. In this report, we have theoretically calculated five new butterfly-shaped fullerene-free acceptors (FD1-FD6) by making end-capped modifications on reference molecule (R) with the purpose to study the improvement in photophysical, opto-electronic, and photo-voltaic properties of newly designed molecules by employing density functional theory (DFT) and time dependent (TD-DFT). Besides, some properties like position of frontier molecular orbitals (FMOs), excitation and binding energy, hole-electron overlap, density of states, overlap density of states, molecular electrostatic potential, open circuit voltage, transition density matrix, and reorganizational energy of electron and hole are also considered and associated with experimentally synthesized reference compound. All calculated molecules displayed a good red-shifting with high charge mobility of electrons among low binding and excitation energies as opposed to reference molecule. Furthermore, all designed molecules (FD1-FD6) and the reference R shows narrow band-gap along-with great charge shifting capability. This theoretical framework proves that end-capped acceptors variation is a modest and effective strategy to accomplish the desirable opto-electronic properties. Therefore, FD1-FD6 are suggested to experimentalist for out-looking future developments to fabricate highly efficient solar cells devices.

scholarly journals Molecular Packing of Non-Fullerene Acceptors for Organic Solar Cells: Distinctive Local Morphology in Y6 Versus ITIC Derivatives

2021 ◽  
Author(s):  
Grit Kupgan ◽  
XianKai Chen ◽  
Jean-Luc Bredas
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Molecular Packing ◽  
Exciton Transport ◽  
Major Interest ◽  
Electron Holes ◽  
Dynamics Simulations ◽  
Conversion Efficiencies

Since a couple of years ago, Y6 has emerged as one of the main non-fullerene acceptors for organic solar cells as its use leads to superior power conversion efficiencies. It is thus of major interest to investigate the multi-scale phenomena that are responsible for Y6’s efficacy. Here, we modeled neat films of Y6 and earlier non-fullerene acceptors, IT-4F and ITIC, using a combination of density functional theory calculations and molecular dynamics simulations, to investigate the various factors that control their charge and exciton transport rates. We find that the molecular packing in Y6 is drastically different from that in IT-4F and ITIC. At the nano-scale, the local morphology of Y6 consists of a large number of directional face-on stackings and well-connected transport networks. Y6 also consistently shows higher electronic couplings for LUMOs, HOMOs, and local excitations than ITIC-type acceptors, which results in fast transport rates for electron, holes, and excitons. Importantly, when considering dimers, their configurations in Y6 are more diverse than in ITIC-type acceptors, with many of those similar to the configurations observed in the Y6 crystal structure reported recently. Most Y6 dimer configurations exhibit strong binding interactions, large electronic couplings, and high transport rates, which when taken together rationalize the better performance of OSCs based on Y6.

Exploring the Effect of Electron Withdrawing Groups on Optoelectronic Properties of Pyrazole Derivatives as Efficient Donor and Acceptor Materials for Photovoltaic Devices

2019 ◽  
Vol 233 (11) ◽  
pp. 1625-1644 ◽  
Author(s):  
Ahmad Irfan ◽  
Mehboobali Pannipara ◽  
Abdullah G. Al-Sehemi ◽  
Muhammad Waseem Mumtaz ◽  
Mohammed A. Assiri ◽  
...  
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
Density Functional ◽  
Dye Sensitized Solar Cells ◽  
Acid Methyl Ester ◽  
Good Choice ◽  
Band Alignment ◽  
Photovoltaic Devices ◽  
Photovoltaic Properties ◽  
Donor And Acceptor

Abstract Multifunctional pyrazole derivative, i.e. 3-amino-1-(5-hydroxy-3-methyl-1H-pyrazol-4-yl)-1H-benzo[f]chromene-2-carbonitrile (PBCC) has been synthesized and characterized. To shed light on various properties of interests, the ground state geometry was optimized by adopting Density Functional Theory (PBE/TZ2P). The effect of different functionals on the absorption wavelengths was studied by using Time-Domain DFT (TDDFT), e.g. GGA functional PBE, hybrid functionals B3LYP and PBE0, rang separated functionals CAM-B3LYP, LCY-PBE and CAMY-B3LYP, Dispersion Corrections PBE-D3 and B3LYP-D3. Among all these functionals PBE and PBE-D3 were found to be good choices which reproduced the absorption spectra of the PBCC. With the aim to enhance the electro-optical, charge transfer and photovoltaic properties, five new derivatives were designed by di-substituting the –F, –Cl, –Br, –COOH and –CN at benzochromene moiety. The electron injection barrier, band gap alignment and related calculated photovoltaic parameters revealed that PBCC and its newly designed derivatives would be proficient to be used in photovoltaic devices. These compounds can be used as donor materials in dye-sensitized solar cells (DSSCs) with favorable type-II band alignment. Moreover, PBCC and most of its derivatives might also be good choice as efficient acceptors with poly(dithieno[3,2-b:2,3-d]pyrrole thiophene) (PDTPr-T) and donor materials with Phenyl-C61-butyric acid methyl ester (PC61BM) in organic solar cells.

scholarly journals Molecular Packing of Non-Fullerene Acceptors for Organic Solar Cells: Distinctive Local Morphology in Y6 Versus ITIC Derivatives

2021 ◽  
Author(s):  
Grit Kupgan ◽  
XianKai Chen ◽  
Jean-Luc Bredas
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Molecular Packing ◽  
Exciton Transport ◽  
Major Interest ◽  
Electron Holes ◽  
Dynamics Simulations ◽  
Conversion Efficiencies

Since a couple of years ago, Y6 has emerged as one of the main non-fullerene acceptors for organic solar cells as its use leads to superior power conversion efficiencies. It is thus of major interest to investigate the multi-scale phenomena that are responsible for Y6’s efficacy. Here, we modeled neat films of Y6 and earlier non-fullerene acceptors, IT-4F and ITIC, using a combination of density functional theory calculations and molecular dynamics simulations, to investigate the various factors that control their charge and exciton transport rates. We find that the molecular packing in Y6 is drastically different from that in IT-4F and ITIC. At the nano-scale, the local morphology of Y6 consists of a large number of directional face-on stackings and well-connected transport networks. Y6 also consistently shows higher electronic couplings for LUMOs, HOMOs, and local excitations than ITIC-type acceptors, which results in fast transport rates for electron, holes, and excitons. Importantly, when considering dimers, their configurations in Y6 are more diverse than in ITIC-type acceptors, with many of those similar to the configurations observed in the Y6 crystal structure reported recently. Most Y6 dimer configurations exhibit strong binding interactions, large electronic couplings, and high transport rates, which when taken together rationalize the better performance of OSCs based on Y6.

scholarly journals Structural, Electronic, and Optical Properties of Group 6 Doped Anatase TiO2: A Theoretical Approach

2021 ◽  
Vol 11 (4) ◽  
pp. 1657
Author(s):  
Petros-Panagis Filippatos ◽  
Nikolaos Kelaidis ◽  
Maria Vasilopoulou ◽  
Dimitris Davazoglou ◽  
Alexander Chroneos
Keyword(s):  
Optical Properties ◽  
Solar Cells ◽  
Electron Transport ◽  
Density Functional ◽  
Perovskite Solar Cells ◽  
Solar Spectrum ◽  
Type Conductivity ◽  
Electronic And Optical Properties ◽  
Group 6 ◽  
Visible Wavelengths

Titania (TiO2) is a key material used as an electron transport in dye-sensitized and halide perovskite solar cells due to its intrinsic n-type conductivity, visible transparency, low-toxicity, and abundance. Moreover, it exhibits pronounced photocatalytic properties in the ultra-violet part of the solar spectrum. However, its wide bandgap (around 3.2 eV) reduces its photocatalytic activity in the visible wavelengths’ region and electron transport ability. One of the most efficient strategies to simultaneously decrease its bandgap value and increase its n-type conductivity is doping with appropriate elements. Here, we have investigated using the density functional theory (DFT), as well as the influence of chromium (Cr), molybdenum (Mo), and tungsten (W) doping on the structural, electronic, and optical properties of TiO2. We find that doping with group 6 elements positively impacts the above-mentioned properties and should be considered an appropriate method for photocatalystic applications. In addition to the pronounced reduction in the bandgap values, we also predict the formation of energy states inside the forbidden gap, in all the cases. These states are highly desirable for photocatalytic applications as they induce low energy transitions, thus increasing the oxide’s absorption within the visible. Still, they can be detrimental to solar cells’ performance, as they constitute trap sites for photogenerated charge carriers.

scholarly journals Single particle dual plasmonic effect for efficient organic solar cells

2021 ◽  
Author(s):  
Adi Prasetio ◽  
Soyeon Kim ◽  
Muhammad Jahandar ◽  
Dong Chan Lim
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
Light Absorption ◽  
Resonance Effect ◽  
Localized Surface Plasmon ◽  
Main Role ◽  
Charge Generation ◽  
One Pot ◽  
Wide Range ◽  
Light Reflectance

AbstractIncorporating localized surface plasmon resonance (LSPR) into organic solar cells (OSCs) is a popular method for improving the power conversion efficiency (PCE) by introducing better light absorption. In this work, we designed a one-pot synthesis of Ag@SiO2@AuNPs dual plasmons and observed an immense increase in light absorption over a wide range of wavelengths. Ag@SiO2 plays the main role in enhancing light absorption near the ultraviolet band. The silica shell can also further enhance the LSP resonance effect and prevent recombination on the surface of AgNPs. The AuNPs on the Ag@SiO2 shell exhibited strong broad visible-light absorption due to LSP resonance and decreased light reflectance. By utilizing Ag@SiO2@AuNPs, we could enhance the light absorption and photoinduced charge generation, thereby increasing the device PCE to 8.57% and Jsc to 17.67 mA cm−2, which can be attributed to the enhanced optical properties. Meanwhile, devices without LSPR nanoparticles and Ag@SiO2 LSPR only showed PCEs of 7.36% and 8.18%, respectively.

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