scholarly journals Light Harvesting and Optical-Electronic Properties of Two Quercitin and Rutin Natural Dyes

2019 ◽  
Vol 9 (12) ◽  
pp. 2567 ◽  
Author(s):  
Dongpeng Zhao ◽  
Qiuchen Lu ◽  
Runzhou Su ◽  
Yuanzuo Li ◽  
Meiyu Zhao
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Fourier Transforms ◽  
Light Harvesting ◽  
Absorption Peak ◽  
Conduction Band Edge ◽  
Photovoltaic Properties ◽  
Functional Theory ◽  
Photoelectric Properties ◽  
Reorganization Energies

The photovoltaic properties of two dyes (quercitin (Q) and rutin (R)) were experimentally investigated. The results showed that Q had excellent photoelectric properties with J s c of 5.480 mA·cm−2, V o c of 0.582 V, η of 2.151% larger than R with J s c of 1.826 mA·cm−2, V o c of 0.547 V, and η of 0.713%. For a better understanding of the photoelectric properties of two molecules and illustrating why the performances of Q is better than R from the micro-level, the UV-VIs spectrum, Fourier transforms infrared (FT-IR) spectrum, and cyclic voltage current characteristics were experimentally investigated. What is more, density functional theory (DFT) and time dependent density functional theory (TD-DFT) have been implemented in theoretical calculation. Based on the calculated results, frontier molecular orbitals (FMOs), charge differential density (CDD), infrared vibration, first hyperpolarizability, projected density orbital analysis (PDOS), electrostatic potential (ESP), and natural bond orbital (NBO) were analyzed. Hole/electron reorganization energies ( λ h / λ e ), light harvesting efficiency (LHE), fluorescent lifetime (τ), absorption peak, and the vertical dipole moment ( μ n o r m a l ) were calculated, and the shift of conduction band edge of a semiconductor (ΔECB) has been analyzed, which has a close relationship with J s c and V o c . The results demonstrated that, due to the higher LHE, τ, μ n o r m a l , and red-shifted absorption peak, Q has better photoelectric properties than R as a promising sensitizer.

Preliminary First Principles Study Of Hf and Zr Aluminates as Replacement High-k Dielectrics

2001 ◽  
Vol 670 ◽  
Author(s):  
Michael Haverty ◽  
Atsushi Kawamoto ◽  
Gyuchang Jun ◽  
Kyeongjae Cho ◽  
Robert Dutton
Keyword(s):  
Density Functional Theory ◽  
Dielectric Constant ◽  
Bulk Density ◽  
First Principles ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Conduction Band Edge ◽  
Functional Theory ◽  
Trade Off ◽  
High K

ABSTRACTBulk Density Functional Theory calculations were performed on Hf and Zr substitutions for Al in κ-alumina. The lowest energy configuration found was an octahedrally coordinated Zr site. Zr dissolution was favorable with an enthalpy of -2eV/unit cell for forming Al1.875Zr0.125O3 from pure Zr and κ-alumina. Hf and Zr substitution for Al atoms introduced empty d-states below the conduction band edge reducing the Eg of pure κ-alumina (7.5eV) to 6.4-5.9eV. The edge of the valence band however remained fixed by the O p-state character. The substitution of Hf and Zr into the alumina structure may lead to a higher dielectric constant, but will also reduce Eg and result in a trade off in tunneling currents in devices.

Exploring the Photovoltaic Properties of Metal Bipyridine Complexes (Metal = Fe, Zn, Cr, and Ru) by Density Functional Theory

2018 ◽  
Vol 73 (4) ◽  
pp. 337-344 ◽  
Author(s):  
Ahmad Irfan ◽  
Ghulam Abbas
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Photovoltaic Performance ◽  
Open Circuit ◽  
Band Alignment ◽  
Structure Property ◽  
Ambient Conditions ◽  
Photovoltaic Properties ◽  
Functional Theory ◽  
Solar Cell Performance

AbstractThe synthesis and characterisation of mononuclear Fe complexes were carried out by using bipyridine (Compound 1) at ambient conditions. Additionally, three more derivatives were designed by substituting the central Fe metal with Zn, Cr, and Ru (Compound 2, Compound 3, and Compound 4), respectively. The ground state geometry calculations were carried out by using density functional theory (DFT) at B3LYP/6-31G** (LANL2DZ) level of theory. We shed light on the frontier molecular orbitals, electronic properties, photovoltaic parameters, and structure–property relationship. The open-circuit voltage is a promising parameter that considerably affects the photovoltaic performance; thus, we have estimated its value by considering the complexes as donors whereas TiO2 and/or Si were used as acceptors. The solar cell performance behaviour was also studied by shedding light on the band alignment and energy level offset.

scholarly journals A Theoretical Investigation of Decorated Novel Triazoles as DSSCs in PV Devices

2021 ◽  
Author(s):  
Louis-Charl Cloete Coetzee ◽  
Adedapo Adeyinka ◽  
Nomampondo Magwa
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Dye Sensitized Solar Cells ◽  
Fluorescence Emission ◽  
Photovoltaic Properties ◽  
Functional Theory ◽  
Dye Sensitized ◽  
Td Dft ◽  
Photovoltaic Applications ◽  
Sensitized Solar Cells

Abstract Some novel metal-free 1,2,4-triazole compounds A1-A8, based on the 3,5-bis(2-hydroxyphenyl)-1,2,4-triazole derivatives were examined for Photovoltaic properties using density functional theory (DFT) and time dependent density functional theory (TD-DFT) calculations for the use of dye sensitized solar cells (DSSCs). Through deductive logic, the fluorescence emission (Φf) and charge collection (ηc) efficiencies of these compounds as dyes were obtained and used to determine each dye’s incident conversion efficiency (IPCE). Furthermore, these parameters were also employed to assess the dye’s potential for photovoltaic technology. However, this technique is more suitable to predict the suitability of the dye for photovoltaic applications, and cannot measure the efficiency of DSSCs

scholarly journals Simulation Study of Structural and Electronic Properties for Adducts complexes of Bis(Acetylacetonato)oxoVandium (IV) with 4-(Para-substituted phenyl)-1,2,3-Selenadiazole

2021 ◽  
Vol 2063 (1) ◽  
pp. 012002
Author(s):  
Dalal H Alsawad ◽  
Ali A Al-Riyahee ◽  
Ali J Hameed
Keyword(s):  
Density Functional Theory ◽  
Electronic Properties ◽  
Molecular Orbital ◽  
Density Functional ◽  
Functional Theory ◽  
Structural And Electronic Properties ◽  
Lowest Unoccupied Molecular Orbital ◽  
Reorganization Energies ◽  
Cis And Trans ◽  
Optimized Geometries

Abstract A series of 4-(para-substituted phenyl)-1,2,3-selenadiazole adducts of [VO(acac)2] were studied by density functional theory (DFT) calculations. The 4-(para-substituted phenyl)-1,2,3-selenadiazole molecules have been selected to be bound with vanadium atom in [VO(acac)2] through Se, N2 and N3. The resulting adducts have been investigated in two geometries (cis and trans) in order to show the effect of such structural change on the electronic properties of the studied adducts. The optimized geometries, (binding and reorganization) energies and the spatial distribution of the highest molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of the adducts are presented and discussed.

scholarly journals Optical Absorption and Electron Injection of 4-(Cyanomethyl)benzoic Acid Based Dyes: A DFT Study

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Yuehua Zhang ◽  
Penghui Ren ◽  
Yuanzuo Li ◽  
Runzhou Su ◽  
Meiyu Zhao
Keyword(s):  
Density Functional Theory ◽  
Benzoic Acid ◽  
Density Functional ◽  
Photovoltaic Performance ◽  
Dye Sensitized Solar Cells ◽  
Electron Injection ◽  
Oxidation Potential ◽  
Conduction Band Edge ◽  
Functional Theory ◽  
Sensitized Solar Cells

Density functional theory (DFT) and time-dependent density functional theory (TDDFT) calculations were carried out to study the ground state geometries, electronic structures, and absorption spectra of 4-(cyanomethyl)benzoic acid based dyes (AG1 and AG2) used for dye-sensitized solar cells (DSSCs). The excited states properties and the thermodynamical parameters of electron injection were studied. The results showed that (a) two dyes have uncoplanar structures along the donor unit and conjugated bridge space, (b) two sensitizers exhibited intense absorption in the UV-Vis region, and (c) the excited state oxidation potential was higher than the conduction band edge of TiO2photoanode. As a result, a solar cell based on the 4-(cyanomethyl)benzoic acid based dyes exhibited well photovoltaic performance. Furthermore, nine dyes were designed on the basis of AG1 and AG2 to improve optical response and electron injection.

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