Search

In present investigation, we limelight the key electro-optical properties including electronic structure, optical, charge transport and nonlinear optical properties of two novel chalcone derivatives (( E )-1-(2,5-Dimethyl-3-Thienyl)-3-(2-hydroxyphenyl)prop-2-en-1-one ( chalc1 ) and (2 E )-3-[4-(Dimethylamino)phenyl]-1-(2,5-dimethyl-3-Thienyl)prop-2-en-1-one ( chalc2 ). The ground (S 0 ) and excited state (S 1 ) geometries are optimized using B3LYP/6-31G** and TD-B3LYP/6-31G** levels of theory, respectively, which show reasonably good agreement to the available experimental data of respective crystal structures. A comprehensive electronic structure-property relationship is elucidated through the prism of frontier molecular orbitals (FMOs), orbital energy gap (E g ) analysis, density of states (DOS), as well as molecular electrostatic potential (MEP) plots. The effect of electron donating groups (-OH and −N(CH 3 ) 2 ) is investigated on the absorption and emission wavelengths, ionization potentials (IP), electron affinities (EA), reorganization energies. Finally, the n -channel charge transport nature of these compounds is considered on the bases of our calculated transfer integrals and intrinsic mobilities. [ABSTRACT FROM AUTHOR]

Pyrazole compounds are gaining noteworthy attention in our daily life from better biological active to the semiconducting materials. Present work deals in depth study of indigenously synthesized pyrazole compound, i.e., 2-[(3,5-dimethyl-1-phenyl-1H-pyrazol-4-yl)methylidene]indan-1,3-dione ( DMPI ) with respect to the structural, electronic, optical and charge transport properties. The ground and excited state geometries were optimized by applying density functional theory (DFT) and time dependent DFT, respectively. The frontier molecular orbitals (FMOs) have been spotlighted. The comprehensible intra-molecular charge transfer (ICT) from the highest occupied molecular orbital (HOMO) to the lowest unoccupied molecular orbital (LUMO) was observed. The absorption and emission wavelengths were studied at the TD-B3LYP/6-31G** level of theory. The total and partial density of states (T/PDOS) has been studied to understanding the contribution of different states in the electronic properties. The ionization potentials (IP), electron affinities (EA), reorganization energies, transfer integrals, intrinsic mobility and structure-property relationship have been discussed intensively. The smaller hole reorganization energy and superior transfer integral values resulting improved hole intrinsic mobility than the electron ones is revealing that DMPI would be better hole transport material. [ABSTRACT FROM AUTHOR]

Using the first principles calculations, optical and nonlinear optical (NLO) properties are calculated for three crossed shaped chromophores having alike benzoic acid π-conjugated side chains but different central cores i.e. phenyl in 1-Ph , pyrazino[2,3- g ]quinoxaline in 2-PyQ and tetrathiafulvalene in 3-TTF . Molecular geometries are effectively reproduced and compared to their experimental crystallographic structures. The third-order NLO polarizability is calculated with three different DFT functionals including M06, PBE0 and B3LYP using 6-311G* basis set. Our calculated third-order NLO polarizability amplitudes and their comparison to those of standard and contemporary NLO chromophores indicate that all the three compounds have remarkably larger NLO response. The γ amplitudes of compounds 1-Ph , 2-PyQ and 3-TTF are 429.6 × 10 −36 , 1871.7 × 10 −36 and 967.5 × 10 −36 esu, respectively, at M06/6-311G* level of theory. Interestingly, in present investigation the γ amplitude of the best-studied NLO compound 2-PyQ is 257 times larger than that of para nitroaniline (7.279 × 10 −36 esu) at the same M06/6-311G* level of theory. The TD-DFT calculations are used to trace the origin of larger NLO response. Additionally, total and partial densities of states are calculated to compare the effect and contributions of central cores in all adopted compounds. Thus, the present investigation will not only highlight the NLO potential of entitled compounds but also provoke the interest of experimentalists to effectively modify the central cores for such other applications. [ABSTRACT FROM AUTHOR]

The degradation of dyes and colors from textile contaminants has been a major source of concern owing to issues with visibility, health, and toxicity. Therefore, the dye must be treated before being released into the environment. Co-precipitation was employed to synthesis pristine and Co (0.01 M, 0.03 M, and 0.05 M) doped NiMnO 3 catalysts for the purpose of this study. Analytical methods such as X-ray diffraction, fourier transform infrared spectroscopy and ultraviolet-visible spectroscopy were utilized in the process of characterizing of the synthesized catalysts. The band gap of NiMnO 3 (3.0 eV) has been confirmed from UV-Vis. spectra and doping has also been shown to cause a reduction in the band gap. In the XRD spectrum, a peak (110) at 36° has confirmed the rhombohedral crystal structure of NiMnO 3. Both intense peaks on 504 and 635 cm−1 in the FTIR spectra also confirmed the functional present in NiMnO 3. These synthesized catalysts were employed for the photocatalytic breakdown of the synthetic dye methylene violet. The highest degradation of methylene violet was obtained by using Co (0.05 M) doped NiMnO 3 (91.9%). Three cycles of recycling showed a modest drop in dye degradation from 91.8% to 90%, indicating the great stability of the catalyst. The major species taking part in photo-catalysis were found to be h+ and .O2- by using IPA, BQ and 2NA-EDTA scavenger. The above results show that Co (0.05) doped NiMnO 3 can be the suitable photocatalyst for the photocatalytic breakdown of methylene violet and it can be also used in different energy storage applications. [ABSTRACT FROM AUTHOR]

• Optoelectronic properties of DPPQ derivatives are analysed at molecular and bulk scales. • Effect of various electron donating amines was explored on various properties of interests. • Green, yellow, orange and red light emitters were explored. • The p -type or balanced charge transport nature of compounds has been explored. • DOS, dielectric constant, conductivity function and intrinsic mobility displayed them as multifunctional materials. Effect of various electron donating amines, i.e. , dimethylamine (DMA), diphenylamine (DPA), phenylnaphthylamine (PNA) and dinaphthylamine (DPA) at 6 position on the electronic, photophysical and charge transfer properties of 1,3-diphenyl-1H-pyrazolo[3,4- b quinolone (DPPQ) as a parent molecule has been explored at the molecular and solid state bulk level. The effect of substituents on absorption and emission was studied at TD-B3LYP/6-31G** level in acetonitrile. The computed emission wavelengths were being red shifted for DMA-DPPQ , DPA-DPPQ , PNA-DPPQ than that of parent molecule which might be green, yellow, orange and red light emitters. The charge transfer nature of various DPPQ derivatives has been explored on the bases of ionization potential, hole extraction potential, electron affinity, reorganization energies, transfer integrals and intrinsic mobility. The DMA substitution at position 6 of DPPQ boost up the electron transfer integrals leading to balanced charge transport for holes and electrons. Moreover, total/partial density of states and optical properties (dielectric constant, extinction coefficient refractive indices, reflectivity and conductivity) at solid state bulk scale have been explored. Different properties of interest at molecular and solid state levels revealed that 1,3-diphenyl-1H-pyrazolo[3,4-b]quinolone derivatives would be efficient materials to be used in multifunctional organic semiconductor devices. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract The graphene nanoribbons (GNRs) have been established for device applications in numerous fields due to their superb electro-optical properties. GNRs are used in many nanoscale electronic devices, e.g., solar cells, semiconductors, field effect transistors and nonlinear optics. The isolated molecule precursor of boron doped GNR parent compound 5,10-bis(10-bromoanthracene-9-yl)-5,10-dihydroboranthrene (Br-GNR) and its newly designed derivatives 5,10-bis(10-fluoroanthracene-9-yl)-5,10dihydroboranthrene (F-GNR) and 5,10-bis(10-chloroanthracene-9-yl)-5,10dihydroboranthrene (Cl-GNR) were optimized using density functional theory (DFT) at PBE0/6-311G* level. By replacing the –Br by –F atoms in Br-GNR, the ionization potential (IP) and electron affinity (EA) declined. The hole and electron reorganization energies (λ(h)/λ(e)) of halogenated doped GNRs has been systematically compared with some standard hole and electron transfer materials. The smaller λ(h) values are showing that the studied compounds would be superior hole transfer candidates. The density of states and optical properties at bulk level (including dielectric function, refractive indices, conductivity and loss function) have been probed. The polarizability (γ) amplitudes of F-GNR, Cl-GNR and Br-GNR are 34, 21 and 22 times larger than that of para -nitroaniline at same PBE0/6-311G* level. The calculated non-linear optical (NLO) polarizability amplitudes, optoelectronic and charge transfer properties showed that all the compounds would be good contenders for NLO and semiconductor devices. [ABSTRACT FROM AUTHOR]

With the aim to tune the optoelectronic, charge transport and nonlinear optical properties, four novel star shaped compounds were designed from the initial structure 4,6-di(anthracenothiophen-2-yl)pyrimidine (DATP). The (2,5-di-(thiophen-2-yl)-4,6-di-(anthracenothiophen-2-yl)pyrimidine) ( 1 ), (2,5-di(benzo-thiophen-2-yl)-4,6-di-(anthracenothiophen-2-yl)pyrimidine) ( 2 ), 2,5-di(naphthothiophen-2-yl)-4,6-di-(anthracene-thiophen-2-yl)-pyrimidine ( 3 ), and 2,4,5,6-tetrakis(anthracene-thiophen-2-yl)pyrimidine ( 4 ) were deliberated by substituting the thiophene, benzothiophene, naphthothiophene and anthracenothiophene moieties at positions 2 and 5 of the pyrimidine unit in DATP, respectively. The ground and excited state geometries were optimized by adopting the density functional theory (DFT) and time-dependent DFT at B3LYP/6-31G** and TD-B3LYP/6-31G** level of theories, respectively. We shed light on the energies of the frontier molecular orbitals (FMOs), energy gaps (E gaps ), absorption, fluorescence, total/partial density of states (T/PDOS), molecular electrostatic potentials (MEP) and non-linear optical (NLO) properties. The comprehensible intra-molecular charge transport has been noticed from side wings to the electron-deficient central core at both the ground and excited states. The increment in the wings length increases the electron affinity, reduces the ionization potential and lowered the hole reorganization energy. The higher electron affinity and smaller hole reorganization energy values revealed that newly designed materials might be thermodynamically more stable with enhanced intrinsic hole mobility. [ABSTRACT FROM AUTHOR]

The naphthalene is good contender which is intensively used in organic semiconductors. Here, three new naphthalene based compounds were prepared by the condensation of 1,5-diaminonaphthalene, 5-methylfurfural and 5-nitrofurfural. The prepared Schiff base compounds were analyzed by Fourier Transmission Infrared spectroscopy (FTIR), UV–vis spectroscopy (UV-vis) and single crystal x-ray studies. The compound 1 was obtained in P21/n crystal packing. A comprehensive electronic structure-property relationship was elucidated through the prism of frontier molecular orbitals (FMOs). The calculated absorption wavelengths at TD-B3LYP/6-31G** level displayed reasonably decent agreement to the experimental data. The effect of electron donating groups and electron withdrawing groups was discussed on optoelectronic properties, ionization potentials, electron affinities and reorganization energies. On the basis of transfer integrals and intrinsic mobility nature of the charge transport of compound 1 was discussed. The electron injection, electronic coupling constant and light harvesting efficiency revealed that the studied Schiff base compounds would be good contestants to be used in dye-sensitized solar cells. Compounds 2 and 3 have 8 and 6 times larger β tot than that of para-nitro aniline revealing that these materials might be good for nonlinear optics as well. [ABSTRACT FROM AUTHOR]

One of the main goals of researchers is to develop renewable, ecologic and efficient energy sources to meet energy needs in the near future. In this context, chalcogenide materials are the most promising candidates for the production of clean energy from solar radiations using a new generation of technologically advanced solar cells. In this paper, we use first-principles GGA+ U calculations to study the optoelectronic and elastic properties of TmCu 3 S 4 (Tm = V, Ta, Nb) in terms of their potential applications in optoelectronic devices. Our calculations show that VCu 3 S 4 is a half-metallic compound, showing metallic properties in the spin up channel and semiconducting properties in the spin down channel. On the other hand, NbCu 3 S 4 and TaCu 3 S 4 are semiconductors. VCu 3 S 4 has a direct bandgap in spin down channel as the CBM (conduction band minima) and VBM (valence band maxima) occur at the same point Γ. However, NbCu 3 Se 4 and TaCu 3 Se 4 are indirect bandgap semiconductors. The values of bandgaps for above-mentioned materials are increased by replacing Nb with Ta and V. The prospect of TmCu 3 S 4 (Tm = V, Ta, Nb) for optoelectronic applications is demonstrated by detailed examination of optical parameters. This study reveals that TmCu 3 S 4 (Tm = V, Ta, Nb) are week reflectors of incoming photons, and a maximum of 50% reflection of incoming photo radiations is depicted by these materials in the upper UV region for both spins. In the elastic properties, the values of Zener anisotropy factor A indicate that the cubic materials mentioned above are anisotropic and have covalent bonds. The material will be brittle if value of the Pugh's ratio (B/G) is less than 1.75, otherwise it will be substantially plastic. In this study, values of Pugh's ratio (B/G) TmCu 3 S 4 (Tm = V, Ta, Nb) are below 1.75. Therefore, these cubic chalcogenides are fragile. [ABSTRACT FROM AUTHOR]

One of the main goals of researchers is to develop renewable, ecologic and efficient energy sources to meet energy needs in the near future. In this context, chalcogenide materials are the most promising candidates for the production of clean energy from solar radiations using a new generation of technologically advanced solar cells. In this paper, we use first-principles GGA+ U calculations to study the optoelectronic and elastic properties of TmCu 3 S 4 (Tm = V, Ta, Nb) in terms of their potential applications in optoelectronic devices. Our calculations show that VCu 3 S 4 is a half-metallic compound, showing metallic properties in the spin up channel and semiconducting properties in the spin down channel. On the other hand, NbCu 3 S 4 and TaCu 3 S 4 are semiconductors. VCu 3 S 4 has a direct bandgap in spin down channel as the CBM (conduction band minima) and VBM (valence band maxima) occur at the same point Γ. However, NbCu 3 Se 4 and TaCu 3 Se 4 are indirect bandgap semiconductors. The values of bandgaps for above-mentioned materials are increased by replacing Nb with Ta and V. The prospect of TmCu 3 S 4 (Tm = V, Ta, Nb) for optoelectronic applications is demonstrated by detailed examination of optical parameters. This study reveals that TmCu 3 S 4 (Tm = V, Ta, Nb) are week reflectors of incoming photons, and a maximum of 50% reflection of incoming photo radiations is depicted by these materials in the upper UV region for both spins. In the elastic properties, the values of Zener anisotropy factor A indicate that the cubic materials mentioned above are anisotropic and have covalent bonds. The material will be brittle if value of the Pugh's ratio (B/G) is less than 1.75, otherwise it will be substantially plastic. In this study, values of Pugh's ratio (B/G) TmCu 3 S 4 (Tm = V, Ta, Nb) are below 1.75. Therefore, these cubic chalcogenides are fragile. [ABSTRACT FROM AUTHOR]

• Electronic and charge transport nature of 10-(1,3-Dithiol-2-ylidene)anthracene based OSMs was explored. • Effect of bridge and anchoring group was probed on intrinsic mobility. • p - or n -type charge transport ability was systematically probed. • 3,4-ethylenedioxythiophene bridge would be decent to design p -type materials. • Dicyanovinylene might be a good for designing n -type semiconductors. Electronic and charge transport nature of 10-(1,3-Dithiol-2-ylidene)anthracene based organic semiconductor materials (OSMs) have been explored at the molecular level. Effect of phenyl and 3,4-ethylenedioxythiophene of conjugated π-bridge and electron anchoring groups (−CHO and dicyanovinylene) was explored on various properties. The dicyanovinylene group lead to diminish electron reorganization energies while 3,4-ethylenedioxythiophene moiety enhance the hole transfer integrals. The dicyanovinylene groups along with 3,4-ethylenedioxythiophene moiety is favouring to reduce the HOMO and LUMO energy levels as well as their energy gap. The 3,4-ethylenedioxythiophene as bridge in OSMs would be decent to design p -type semiconductors. It is anticipated that dicyanovinylene as anchoring group might be a good approach for designing n -type semiconductors. The p - or n -type charge transport ability of anthracene derivatives was probed here. The transfer integrals, frontier molecular orbitals (FMO), ionization energy (IE), electron affinity (EA), reorganization energy, and intrinsic mobility showed that anthracene based derivatives might be proficient competitors to be applied in semiconductor devices. [ABSTRACT FROM AUTHOR]

Herein we report the crystal structure geometry, optoelectronic and charge transport properties of (E)-1-(4-Bromophenyl)-3-(2-chlorophenyl)prop-2-en-1-one (1), (E)-3-(3-Bromophenyl)-1-(4-methoxyphenyl)prop-2-en-1-one (2) and (E)-3-(4-Chlorophenyl)-1-(2-furyl)prop-2-en-1-one (3) chalcone derivatives. In experimental part UV–vis-NIR, X-ray diffraction and Photoluminescence spectroscopy techniques were used. Additionally, quantum chemical density functional theory calculations were executed with a clear view to explore the linear optical, second and third-order nonlinear optical (NLO) properties as well as transfer integrals of all three systems. The experimental and theoretically calculated properties are found to be in excellent accord with each other. Comprehensible intra- and inter-molecular charge transport was observed from occupied to unoccupied molecular orbitals illuminating that these chalcones would be good choice to be used in various semiconductor devices. The compound (3) is found to have better NLO activities and thermal stability compared to (1) and (2). Larger electron transfer integral values than hole ones exposed that studied compounds would be better electron transport materials and can function as n -type in organic semiconductor devices. [ABSTRACT FROM AUTHOR]