scholarly journals Density Functional Theory (DFT) Study of Electronic and Optical Properties of Donor (D)- Acceptor (A) Monomers Based on 2,7-Carbazole Linked with Some Acceptor Groups

2021 ◽  
Vol 33 (9) ◽  
pp. 2073-2081
Author(s):  
Charitha Annam ◽  
N. Murali Krishna ◽  
Mannam Subbarao
Keyword(s):  
Optical Properties ◽  
Solar Cells ◽  
Organic Solar Cells ◽  
Density Functional ◽  
Open Circuit ◽  
Optoelectronic Properties ◽  
Basis Set ◽  
Bandgap Energy ◽  
Electronic And Optical Properties ◽  
Solvent Phase

In present study, a progression of low bandgap carbazole molecules was developed and rendered to increase their performance for organic solar cells. Thus, a design of D-A monomers from 2,7-carbazole donors (D) and a few acceptors (A) based D-A monomers was attempted. The calculation of the electronic and optical properties of the D-A monomers considered was based on the techniques of DFT and TD-DFT at the level of B3LYP with a basis set of 6-31G (d) in the gas and chlorobenzene. The HOMO and LUMO orbital energies, the bandgap energy (Eg), and the open-circuit voltage (VOC) were calculated in the gas and solvent phase. The impacts of the acceptor groups on the calculations and optoelectronic properties of these D-A monomers are discussed in the study of the link between the electronic structure and the optoelectronic properties. Some of these D-A monomers suggested that the after-effects of this work are a good possibility for formation of organic solar cells.

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.

A comparative study of structural, electronic and optical properties based on metal-doped methylammonium lead halidesviafirst-principles calculations

2019 ◽  
Vol 43 (24) ◽  
pp. 9453-9457 ◽  
Author(s):  
Diwen Liu ◽  
Huijuan Jing ◽  
Rongjian Sa ◽  
Kechen Wu
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Solar Cells ◽  
Comparative Study ◽  
Density Functional ◽  
Perovskite Solar Cells ◽  
Functional Theory ◽  
Electronic And Optical Properties ◽  
Metal Doped

To reduce the toxicity of Pb in perovskite solar cells, the structural stabilities, and electronic and optical properties of the mixed perovskites MAPb0.75B0.25I3(B = Mg, Ca, Sr, and Ba) were predicted using density functional theory.

Tuning of optoelectronic properties of triphenylamines-based donor materials for organic solar cells

2019 ◽  
Vol 18 (07) ◽  
pp. 1950036
Author(s):  
Maria Naeem ◽  
Sobia Jabeen ◽  
Rasheed Ahmad Khera ◽  
Usama Mubashar ◽  
Javed Iqbal
Keyword(s):  
Solar Cells ◽  
Acrylic Acid ◽  
Organic Solar Cells ◽  
Density Functional ◽  
Acid Methyl Ester ◽  
Reorganization Energy ◽  
Optoelectronic Properties ◽  
Functional Theory ◽  
Acid Methyl ◽  
Donor Moiety

In the present study, four molecules have been designed by substituting various acceptor moieties around the triphenylamine donor moiety like 2-cyano acrylic acid (R), 2-methylene malonitrile (M1), 2-cyano acrylic acid methyl ester(M2), 2-(2-methylene-3-oxo-indan-1-ylidene)-malonitrile (M3), 2-(6,7-difluoro-2-methylene-3-oxo-indan-1-ylidene)-malonitrile (M4), respectively. CAM-B3LYP/6-31G (d, p) level of theory by using density functional theory (DFT) has been used for the investigation of optoelectronic properties of four new triphenylamine (TPA)-based donor materials (M1–M4) for organic solar cells. In comparison with the recently reported reference molecule, the optoelectronic properties of designed molecules were evaluated. M4 showed absorption maxima at 520[Formula: see text]nm due to extended conjugation with bridged thiophene group. Results of reorganization energy calculations also favor M4 exhibiting highest transfer rate of hole as depicted from its low reorganization energy of hole ([Formula: see text].

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.

The electronic and optical properties of SiO2–Al–SiO2 with density functional theory

2021 ◽  
pp. 2150136
Author(s):  
Geoffrey Tse
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Energy Gap ◽  
Optoelectronic Device ◽  
Bandgap Energy ◽  
Al Alloy ◽  
Total Thickness ◽  
Functional Theory ◽  
Electronic And Optical Properties ◽  
Visible Part

In this work, a novel stishovite–aluminum alloy with chemical formula SiO2–Al–SiO2 is proposed. The structural, electronic and optical properties were obtained using GGA-PBE functional. The study of electronic properties of SiO2–Al–SiO2 shows that it has a bandgap energy at 22 meV, compared to a much wider energy gap inside stishovite. The band structure of SiO2–Al–SiO2 reported in this work indicates that the SiO2–Al alloy proposed is found to be a semi-metal. Also, we report a reflectivity of 73% (2.53 eV) and 70% (7.97 eV), based on 8.36 nm of its total thickness. The strong optical absorption at 2.11 eV and 5.79 eV is suggesting the SiO2–Al–SiO2 can be used as both visible part (orange) sensing and the UV photodetectors. Thus, the SiO2–Al alloy can have potential application in optoelectronic device fabrications.

scholarly journals First-Principles Studies on Structural, Electronic and Optical Properties of Fe-doped Nis2 Counter Electrode for Dye-Sensitized Solar Cells using Dft+U

2020 ◽  
Vol 17 (2) ◽  
pp. 81
Author(s):  
Nur Aisyah Ab Malik Marwan ◽  
Nurakma Natasya Md Jahangir Alam ◽  
Mohd Hazrie Samat ◽  
Muhammad Zamir Mohyedin ◽  
Nur Hafiz Hussin ◽  
...  
Keyword(s):  
Optical Properties ◽  
Solar Cells ◽  
First Principles ◽  
Density Functional ◽  
Counter Electrode ◽  
Dye Sensitized Solar Cells ◽  
Dft Method ◽  
Electronic And Optical Properties ◽  
Dye Sensitized ◽  
Sensitized Solar Cells

The structural, electronic and optical properties of nickel disulfide (NiS2) and iron (Fe)-doped NiS2 were computed by using first-principles calculations through the density functional theory (DFT) method. The Fe was used as a dopant element to understand the behavior and the key mechanism of Fe-doped NiS2 as a counter electrode in dye-sensitized solar cells (DSSC). The results indicated that the structural properties of the NiS2 as the cubic crystal structure with the space group Pa3 (205) (pyrite structure type) agree with experimental data. The density of states (DOS) of NiS2 and Fe-doped NiS2 shows a gapless bandgap due to Mott insulator behavior. As for optical properties, the optical absorption of NiS2 is shifted towards the infrared (IR) region when doping with Fe while the conductivity of Fe-doped NiS2 is slightly higher in conductivity. These optical properties show that Fe-doped NiS2 is good for photocatalytic activity and may provide an excellent electron charge transfer for a counter electrode in DSSC

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