scholarly journals Synthesis and Thermal, Photophysical, Electrochemical Properties of 3,3-di[3-Arylcarbazol-9-ylmethyl]oxetane Derivatives

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5569
Author(s):  
Mateusz Korzec ◽  
Daiva Tavgeniene ◽  
Nizy Sara Samuel ◽  
Raminta Beresneviciute ◽  
Gintare Krucaite ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Electrochemical Properties ◽  
Density Functional ◽  
Energy Levels ◽  
Perovskite Solar Cells ◽  
Frontier Molecular Orbital ◽  
Orbital Energy ◽  
Hole Transporting ◽  
Photoluminescence Studies ◽  
The Impact

Novel oxetane-functionalized derivatives were synthesized to find the impact of carbazole substituents, such as 1-naphtyl, 9-ethylcarbazole and 4-(diphenylamino)phenyl, on their thermal, photophysical and electrochemical properties. Additionally, to obtain the optimized ground-state geometry and distribution of the frontier molecular orbital energy levels, density functional theory (DFT) calculations were used. Thermal investigations showed that the obtained compounds are highly thermally stable up to 360 °C, as molecular glasses with glass transition temperatures in the range of 142–165 °C. UV–Vis and photoluminescence studies were performed in solvents of differing in polarity, in the solid state as a thin film on glass substrate, and in powders, and were supported by DFT calculations. They emitted radiation both in solution and in film with photoluminescence quantum yield from 4% to 87%. Cyclic voltammetry measurements revealed that the materials undergo an oxidation process. Next, the synthesized molecules were tested as hole transporting materials (HTM) in perovskite solar cells with the structure FTO/b-TiO2/m-TiO2/perovskite/HTM/Au, and photovoltaic parameters were compared with the reference device without the oxetane derivatives.

scholarly journals DFT Characteristics of Charge Transport in DBTP-Based Hole Transport Materials

2019 ◽  
Vol 9 (11) ◽  
pp. 2244 ◽  
Author(s):  
Ming Qiu ◽  
Weiwei Pei ◽  
Qiuchen Lu ◽  
Zhuo Li ◽  
Yuanzuo Li ◽  
...  
Keyword(s):  
Density Functional ◽  
Perovskite Solar Cells ◽  
Hole Transport ◽  
Frontier Molecular Orbital ◽  
Functional Theory ◽  
Photoelectric Properties ◽  
Hole Transporting ◽  
Negative Effect ◽  
Hopping Model ◽  
Ground State Geometry

To improve the hole-transport ability and photoelectric properties of perovskite solar cells, the ground-state geometry, frontier molecular orbital, and mobility of two organic molecules were investigated using density functional theory (DFT) with the Marcus hopping model. The absorption spectra were calculated using time-dependent DFT. The result indicated that the increase in the conjugated chain and change in the substituted group location from meta to para cause low mobility, which has a negative effect on the hole-transporting ability.

scholarly journals Fluorescence quenching based detection of nitroaromatics using luminescent triphenylamine carboxylic acids

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aamnayee Mishra ◽  
R. Dheepika ◽  
P. A. Parvathy ◽  
P. M. Imran ◽  
N. S. P. Bhuvanesh ◽  
...  
Keyword(s):  
Carboxylic Acids ◽  
Density Functional ◽  
Picric Acid ◽  
Energy Levels ◽  
Density Functional Theory Calculations ◽  
Frontier Molecular Orbital ◽  
Orbital Energy ◽  
Spectroscopic Techniques ◽  
Contact Mode ◽  
Research Fields

AbstractDetection of nitroaromatics employing greener techniques has been one of the most active research fields in chemistry. A series of triphenylamine (TPA) functionalized carboxylic acids were synthesized and characterized using various spectroscopic techniques including single-crystal X-ray diffraction analysis. The interaction of carboxylic acid-decorated TPAs with nitroaromatic compounds was photophysically explored using absorption and emission spectroscopy. Stern–Volmer plot accounts for the appreciable quenching constant of the TPA-acids. Density functional theory calculations were carried out to study the new compounds' frontier molecular orbital energy levels and the possible interactions with picrate anion and revealed an unusual charge transfer interaction between acids and picrate anion. The contact mode detection shows the TPA-acids can be used as dip-strip sensors for picric acid detection.

scholarly journals Rhodanine-Bridged Core-Expanded Naphthalene Diimide Derivatives for n-Type Semiconductors

2020 ◽  
Vol 02 (02) ◽  
pp. 165-172
Author(s):  
Jiangao Li ◽  
Jing Li ◽  
Congwu Ge ◽  
Xike Gao
Keyword(s):  
Energy Levels ◽  
Perovskite Solar Cells ◽  
Frontier Molecular Orbital ◽  
Orbital Energy ◽  
Organic Thin Film ◽  
Optical Band Gaps ◽  
Naphthalene Diimide ◽  
T1 And T2 ◽  
Naphthalene Diimides ◽  
Improve Device

The core expansion of naphthalene diimides (NDIs) is an effective strategy to modulate frontier molecular orbital energy levels and improve device performances. Herein two new rhodanine-bridged and core-extended NDIs T1 and T2 were designed and synthesized. The rhodanine moiety could act not only as a π-spacer to enlarge the molecular conjugated system, but also as an electron-donating unit to tune the molecular energy levels. As a result, both T1 and T2 showed slightly lower lying LUMO energy levels (< − 4.2 eV) by ca. 0.1 eV and narrower optical band gaps (ca. 1.5 eV) by 0.5 eV compared to those of n-type organic semiconductor (OSC) NDI2DT-DTYM2.The solution-processed organic thin-film transistors based on T1 and T2 exhibited electron motilities in the range of 10−4–10−3 cm2 V−1 s−1, and the inverted perovskite solar cells constructed using T2 as electron transport materials provided a power conversion efficiency value of 8.82%. The results demonstrated that embedding rhodanine units in a NDI2DT-DTYM2 backbone is an effective approach to tune the energy levels and optical properties of OSCs, providing a new way to construct novel n-type OSCs with multifunctional optoelectronic applications.

scholarly journals A New Piano-Stool Ruthenium(II) P-Cymene-Based Complex: Crystallographic, Hirshfeld Surface, DFT, and Luminescent Studies

Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 13
Author(s):  
Mohd. Muddassir ◽  
Abdullah Alarifi ◽  
Mohd. Afzal
Keyword(s):  
Density Functional ◽  
Weak Interactions ◽  
Energy Levels ◽  
Hirshfeld Surface ◽  
Binding Energies ◽  
Orbital Energy ◽  
Aminosalicylic Acid ◽  
Full Characterization

A new complex (Ru(η6-p-cymene)(5-ASA)Cl2) (1) where 5-ASA is 5-aminosalicylic acid has been prepared by reacting the ruthenium arene precursors ((η6-arene)Ru(μ-Cl)Cl)2, with the 5-ASA ligands in a 1:1 ratio. Full characterization of complex 1 was accomplished by elemental analysis, IR, and TGA following the structure obtained from a single-crystal X-ray pattern. The structural analysis revealed that complex 1 shows a “piano-stool” geometry with Ru-C (2.160(5)- 2.208(5)Å), Ru-N (2.159(4) Å) distances, which is similar to equivalents sister complex. Density functional theory (DFT) was used to calculate the significant molecular orbital energy levels, binding energies, bond angles, bond lengths, and spectral data (FTIR, NMR, and UV–VIS) of complex 1, consistent with the experimental results. The IR and UV–VIS spectra of complex 1 were computed using all of the methods and choose the most appropriate way to discuss. Hirshfeld surface analysis was also executed to understand the role of weak interactions such as H⋯H, C⋯H, C-H⋯π, and vdW interactions, which play a significant role in the crystal environment’s stability. Moreover, the luminescence results at room temperature show that complex 1 gives a more intense emission band positioned at 465 nm upon excitation at 330 nm makes it a suitable candidate for the building of photoluminescent material.

scholarly journals Theoretical Study of Solvent Effects on the Electronic and Thermodynamic Properties of Tetrathiafulvalene (TTF) Molecule Based on DFT

2021 ◽  
pp. 42-54
Author(s):  
Rabiu Nuhu Muhammad ◽  
N. M. Mahraz ◽  
A. S Gidado ◽  
A. Musa
Keyword(s):  
Thermodynamic Properties ◽  
Bond Length ◽  
Density Functional ◽  
Theoretical Study ◽  
Energy Gap ◽  
Basis Set ◽  
Basis Sets ◽  
Frontier Molecular Orbital ◽  
Orbital Energy ◽  
Chemical Hardness

Tetrathiafulvalene () is an organosulfur compound used in the production of molecular devices such as switches, sensors, nonlinear optical devices and rectifiers. In this work, a theoretical study on the effects of solvent on TTF molecule was investigated and reported based on Density Functional Theory (DFT) as implemented in Gaussian 03 package using B3LYP/6-31++G(d,p) basis set. Different solvents were introduced as a bridge to investigate their effects on the electronic structure. The HUMO, LUMO, energy gap, global chemical index, thermodynamic properties, NLO and DOS analysis of the TTF molecule in order to determine the reactivity and stability of the molecule were obtained. The results obtained showed that the solvents have effects on the electronic and non-linear-optical properties of the molecule. The optimized bond length revealed that the molecule has strong bond in gas phase with smallest bond length of about 1.0834Å than in the rest of the solvents. It was observed that the molecule is more stable in acetonitrile with HOMO-LUMO gap and chemical hardness of 3.6373eV and 1.8187eV respectively. This indicates that the energy gap and chemical hardness of TTF molecule increases with the increase in polarity and dielectric constant of the solvents. The computed results agreed with the results in the literature. The thermodynamics and NLO properties calculation also indicated that TTF molecule has highest value of specific heat capacity (Cv), total dipole moment () and first order hyperpolarizability () in acetonitrile, while acetone has the highest value of entropy and toluene has a slightly higher value of zero point vibrational energy (ZPVE) than the rest of the solvents. The results show that careful selection of the solvents and basis sets can tune the frontier molecular orbital energy gap of the molecule and can be used for molecular device applications.

Stable perovskite solar cells with efficiency exceeding 24.8% and 0.3-V voltage loss

Science ◽  
2020 ◽  
Vol 369 (6511) ◽  
pp. 1615-1620 ◽  
Author(s):  
Mingyu Jeong ◽  
In Woo Choi ◽  
Eun Min Go ◽  
Yongjoon Cho ◽  
Minjin Kim ◽  
...  
Keyword(s):  
High Efficiency ◽  
Noncovalent Interactions ◽  
Energy Levels ◽  
Perovskite Solar Cells ◽  
Structure Property ◽  
Large Area ◽  
Long Term Stability ◽  
Voltage Loss ◽  
Hole Transporting ◽  
Hole Transporting Material

Further improvement and stabilization of perovskite solar cell (PSC) performance are essential to achieve the commercial viability of next-generation photovoltaics. Considering the benefits of fluorination to conjugated materials for energy levels, hydrophobicity, and noncovalent interactions, two fluorinated isomeric analogs of the well-known hole-transporting material (HTM) Spiro-OMeTAD are developed and used as HTMs in PSCs. The structure–property relationship induced by constitutional isomerism is investigated through experimental, atomistic, and theoretical analyses, and the fabricated PSCs feature high efficiency up to 24.82% (certified at 24.64% with 0.3-volt voltage loss), along with long-term stability in wet conditions without encapsulation (87% efficiency retention after 500 hours). We also achieve an efficiency of 22.31% in the large-area cell.

scholarly journals Resolving Site-Specific Energy Levels of Small-Molecule Donor-Acceptor Heterostructures Close to Metal Contacts

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1618
Author(s):  
Amani Benhnia ◽  
Shinta Watanabe ◽  
Rouzhaji Tuerhong ◽  
Masato Nakaya ◽  
Jun Onoe ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Density Functional ◽  
Energy Levels ◽  
Active Material ◽  
Single Atom ◽  
Scanning Tunneling ◽  
Metal Contacts ◽  
Model Complex ◽  
Donor Acceptor ◽  
Organic Optoelectronic

The active material of optoelectronic devices must accommodate for contacts which serve to collect or inject the charge carriers. It is the purpose of this work to find out to which extent properties of organic optoelectronic layers change close to metal contacts compared to known properties of bulk materials. Bottom-up fabrication capabilities of model interfaces under ultrahigh vacuum and single-atom low temperature (LT)-STM spectroscopy with density functional theory (DFT) calculations are used to detect the spatial modifications of electronic states such as frontier-orbitals at interfaces. The system under consideration is made of a silver substrate covered with a blend of C60 and ZnPc molecules of a few monolayers. When C60 and ZnPc are separately adsorbed on Ag(111), they show distinct spectroscopic features in STM. However, when C60 is added to the ZnPc monolayer, it shows scanning tunneling spectra similar to ZnPc, revealing a strong interaction of C60 with the ZnPc induced by the substrate. DFT calculations on a model complex confirm the strong hybridization of C60 with ZnPc layer upon adsorption on Ag(111), thus highlighting the role of boundary layers where the donor-acceptor character is strongly perturbed. The calculation also reveals a significant charge transfer from the Ag to the complex that is likely responsible for a downward shift of the molecular LUMO in agreement with the experiment.

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.

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