Papers by Mazmira Mohamad
Organic semiconductor materials (OSMs) involving thiophene, vinazene, di-indenoperylene (DIP) and... more Organic semiconductor materials (OSMs) involving thiophene, vinazene, di-indenoperylene (DIP) and copper phthalocyanine (CuPc) are computationally explored at both the isolated molecule and the molecular crystal levels, to expose their potential in optoelectronics. The calculations are performed within the first-principles pseudo-potential quantum mechanical approaches designed within density functional theory at the level of different flavors of exchange-correlation energy/potential functional. All the studied molecules exhibit π-orbital and free electron pairs. The study revealed that the total energy values of isolated molecules of thiophene, vinazene, di-indenoperylene (DIP) and CuPc are 552.7140Ha, 487.7079Ha, 1227.9865Ha and 1887.9308Ha respectively, and those for the corresponding molecular crystals are 5337.5117Ha, 3901.8748Ha, 2455.2992Ha and 3775.2523Ha respectively. In the electronic structure investigations, it is found that the delocalization of electrons from the π-con...
Journal of Nanomaterials & Molecular Nanotechnology
Interfacial study between thiophene molecule and graphene surface is presented by employing densi... more Interfacial study between thiophene molecule and graphene surface is presented by employing density functional theory methods. To do so, interfacing separation distance is varied from 1.00A to 2.50A. Our reported HOMO-LUMO energy gap values, adsorption energy as well as binding energy show the existence of intermolecular forces accumulated from the attractive van der Waals and Pauli repulsion forces. It is noted subsequently that the growing intermolecular forces are very sensitive even to relatively a small change in the interfacing separation distance between the molecule and surface. In the electronic density of states, dense electrons population of the thiophene/graphene system is found with appearance of spinpolarization at energy Fermi level. Moreover, a slight magnetic behaviour on thiophene molecule, accompanied by a decrease in the magnetization of graphene surface, is observed in the presence of the molecule near to the surface.
Jurnal Teknologi, 2016
In this study, we performed our calculations using the full-potential linearized-augmented plane ... more In this study, we performed our calculations using the full-potential linearized-augmented plane wave (FP-LAPW) method as implemented in the WIEN2k code based on DFT. The generalized gradient functional with the Wu-Cohen (WC) parameterization was used to evaluate the structural, electronic, optical and thermoelectric properties of the materials under this study. We have calculated the structural parameters and our obtained results are in good agreement with available experimental and previous theory calculations. The density of states and band structure figures have been calculated and analyzed. The optical properties that covered by dielectric function, absorption coefficient, refractive index, extinction coefficient, reflectivity and energy-loss function have been calculated and analyzed in a range energy from 0eV to 30eV.
Journal of Nanomaterials & Molecular Nanotechnology
Interfacial study between thiophene molecule and graphene surface is presented by employing densi... more Interfacial study between thiophene molecule and graphene surface is presented by employing density functional theory methods. To do so, interfacing separation distance is varied from 1.00A to 2.50A. Our reported HOMO-LUMO energy gap values, adsorption energy as well as binding energy show the existence of intermolecular forces accumulated from the attractive van der Waals and Pauli repulsion forces. It is noted subsequently that the growing intermolecular forces are very sensitive even to relatively a small change in the interfacing separation distance between the molecule and surface. In the electronic density of states, dense electrons population of the thiophene/graphene system is found with appearance of spinpolarization at energy Fermi level. Moreover, a slight magnetic behaviour on thiophene molecule, accompanied by a decrease in the magnetization of graphene surface, is observed in the presence of the molecule near to the surface.
Chemistry Central journal, Jan 2, 2017
Theoretical simulations were designed by first principles approach of density functional theory t... more Theoretical simulations were designed by first principles approach of density functional theory to investigate the structural and optoelectronic properties of different structural classes of perylene; isolated perylene, diindeno[1,2,3-cd:1',2',3'-lm]perylene (DIP) molecule and DIP molecular crystal. The presence of molecular interactions in DIP crystal proved its structure-dependent behaviours. The herringbone molecular arrangement of DIP crystal has influenced the electronic properties by triggering the intermolecular interactions that reduced the energy gaps between HOMO and LUMO of the crystal. Strong hybridization resulting from dense charges population near zero Fermi energy has pushed valence band maxima in the density of states of all perylene structures to higher energies. Under small energy input, charges are transferred continuously as observed in the spectra of conductivity and dielectric. The existence of strong absorption intensities are consistent with the ...
Current Applied Physics, 2017
Journal of molecular modeling, 2016
Some important optoelectronic properties of naphtho[2,1-b:6,5-b']difuran (DPNDF) and its two ... more Some important optoelectronic properties of naphtho[2,1-b:6,5-b']difuran (DPNDF) and its two derivatives have been limelighted by applying the density functional theory (DFT). Due to their low cost, high stability and earth abundance, the DPNDF and its derivatives are considered as potential organic semiconductor materials for their optoelectronics applications. Highly proficient derivatives are obtained systematically by attaching -CN (cyanide) to DPNDF at various sites. Our calculations indicate that DPNDF has a wide and direct band gap with an energy gap of 3.157 eV. Whereas the band gaps of its derivatives are found to be decreased by 88 meV for derivative "a" and 300 meV for derivative "b" as a consequence of p orbitals present in C and N atoms in derivative structures. The narrowing of the energy gap and density of states for the derivatives of DPNDF in the present investigation suggest that energy gap can be engineered for desirable optoelectronic appl...
Journal of Molecular Modeling, 2016
Some important optoelectronic properties of naphtho[2,1-b:6,5-b&a... more Some important optoelectronic properties of naphtho[2,1-b:6,5-b']difuran (DPNDF) and its two derivatives have been limelighted by applying the density functional theory (DFT). Due to their low cost, high stability and earth abundance, the DPNDF and its derivatives are considered as potential organic semiconductor materials for their optoelectronics applications. Highly proficient derivatives are obtained systematically by attaching -CN (cyanide) to DPNDF at various sites. Our calculations indicate that DPNDF has a wide and direct band gap with an energy gap of 3.157 eV. Whereas the band gaps of its derivatives are found to be decreased by 88 meV for derivative "a" and 300 meV for derivative "b" as a consequence of p orbitals present in C and N atoms in derivative structures. The narrowing of the energy gap and density of states for the derivatives of DPNDF in the present investigation suggest that energy gap can be engineered for desirable optoelectronic applications via derivatives designing. Furthermore, their obtained results for optical parameters such as the dielectric and conductivity functions, reflectivity, refractive index, and the extinction coefficients endorses their aptness for optoelectronic applications. Graphical Abstract Real part of dielectric function for derivative "b".
ECS Journal of Solid State Science and Technology, 2016
6 7 The analysis of electrical and optical properties of organic semiconductor materials with qua... more 6 7 The analysis of electrical and optical properties of organic semiconductor materials with quantum mechanically approaches is a comprehensive tool to get close outlook about their performance in optoelectronic devices. By adopting ab initio approach of Density Functional Theory (DFT) implemented within DMol3 code, optoelectronic characterization of isolated single molecule and molecular crystal in β phase of Cu-Phthalocyanine is studied. It was observed that the stacking herringbone geometry of CuPc molecule in β-CuPc subsequently initiates the formation of covalent bonding between the molecules. However reactions with copper atom, existence of nitrogen atoms and accumulation of free charges greatly affect the electronic properties of CuPc molecule and β-CuPc. The lingering of free charges in β-CuPc is found to give rise to dense electrons population accompanied with an intense optical spectra. An extremely high absorption and low value of the loss function have been observed on the optical part of this study as well.
Computational Materials Science, 2016
III–V compounds containing heavy Bi anion are distinguished from remaining III–V family in terms ... more III–V compounds containing heavy Bi anion are distinguished from remaining III–V family in terms of their narrower electronic energy gap and potential application for infrared/near infra devices. In the present work, modeling of X–Bi (X = B, Al, Ga and In) compounds and the investigations pertaining to their physical properties were carried out using density functional theory (DFT) based full-potential linearized augmented plane wave plus local orbital, FP-L(APW + lo) approach within various functional of the exchange correlation potentials. The calculated total energies of X–Bi in various geometries reveal that zinc blende phase is the stable ground state structure of BBi, AlBi and GaBi. However, InBi adapts PbO phase at ground state. It was also found that BBi exhibit an electronic structure with an indirect energy gap. However, AlBi, GaBi and InBi are semi-metallic with a narrower or zero band gap. The calculation of the optical properties show that among X–Bi compounds, BBi was found to exhibit higher absorption coefficient values, lower reflectivity and refractive index, enlightening their potential for infrared/near infra devices and other optoelectronic applications as well.
Advanced Materials Research, 2015
The injection impurity element into ZnO has added new dimension to its versatile applications par... more The injection impurity element into ZnO has added new dimension to its versatile applications particularly in spintronics and optoelectronics. In this work, we are reporting effect of non magnetic Ti, and magnetic V impurities in ZnO. The substitution of impurity atoms have been done in ground state wurtzite (WZ) and meta stable zinc-blende (ZB) structure. Our investigations have revealed a small difference in WZ and ZB geometries of contaminated ZnO reflecting on the possibility of their experimental fabrication. Spin polarized electronic structures resembled nonmagnetic nature of Ti:ZnO in WZ and magnetic nature in ZB geometry. Similarly introduction of V in to ZnO induced magnetization in ZnO in both WZ and ZB geometry. For these investigations, we have adapted DFT approach using FP-L(APW+lo) method implemented in WIEN2k code.
Advanced Materials Research, 2014
Gallium Arsenide (GaAs) because of having unique characteristics like direct band gap, higher ele... more Gallium Arsenide (GaAs) because of having unique characteristics like direct band gap, higher electron mobility and saturated electron velocity etcetera, has wide applications specifically in optoelectronic devices. In this research work we present a comprehensive density functional theory (DFT) based first principles study of optical properties of GaAs. Exchange correlation functional (XC) play a key role in the DFT investigations. A comparative study of the optical properties is presented based upon local density approximation (LDA) by Perdew and wang, Perdew-Burke-Ernzerhof parameterized generalized gradient approximation (GGA-PBE), Wu-Cohen parameterized GGA (GGA-WC) and Engel and Vosko proposed GGA (GGA-EV). Computations in this study have been performed by full potential (FP) linearized augmented plane wave (LAPW) plus local orbitals (lo) approach designed within DFT as realized in the computational code WIEN2k. Our investigations, for the optical properties of GaAs with menti...
Journal of Molecular Modeling, 2015
Escalating demand for sustainable energy resources, because of the rapid exhaustion of convention... more Escalating demand for sustainable energy resources, because of the rapid exhaustion of conventional energy resources as well as to maintain the environmental level of carbon dioxide (CO2) to avoid its adverse effect on the climate, has led to the exploitation of photovoltaic technology manifold more than ever. In this regard organic materials have attracted great attention on account of demonstrating their potential to harvest solar energy at an affordable rate for photovoltaic technology. 2-vinyl-4,5-dicyanoimidazole (vinazene) is considered as a suitable material over the fullerenes for photovoltaic applications because of its particular chemical and physical nature. In the present study, DFT approaches are employed to provide an exposition of optoelectronic properties of vinazene molecule and molecular crystal. To gain insight into its properties, different forms of exchange correlation energy functional/potential such as LDA, GGA, BLYP, and BL3YP are used. Calculated electronic structure of vinazene molecule has been displayed via HOMO-LUMO isosurfaces, whereas electronic structure of the vinazene molecular crystal, via electronic band structure, is presented. The calculated electronic and optical properties were analyzed and compared as well. Our results endorse vinazene as a suitable material for organic photovoltaic applications.
Intermetallics, 2011
ABSTRACT Using a density functional scheme, we have investigated for the first time the structura... more ABSTRACT Using a density functional scheme, we have investigated for the first time the structural, electronic, elastic and thermal properties of the ideal cubic antiperovskite carbides ACRu3 (A = V, Nb, Ta). The computed equilibrium lattice constants are in excellent agreement with the experimental data. The electronic band structures and densities of states profiles show that the studied compounds are conductors. Analysis of atomic site projected local density of states reveals that the bonding character may be described as a mixture of covalent–ionic and, due to the d states in the vicinity of the Fermi level, metallic. Pressure dependence up to 50 GPa of the single crystal and polycrystalline elastic constants has been investigated in details. Analysis of the B/G ratios shows that VCRu3 is slightly brittle while NbCRu3 and TaCRu3 are slightly ductile. We have estimated the sound velocities in the principal directions. Through the quasi-harmonic Debye model, in which the phononic effects are taken into account, the temperature and pressure effects on the lattice constant, bulk modulus, heat capacity and Debye temperature are performed.
Intermetallics, 2012
ABSTRACT The crystal and electronic structures, and the thermodynamic properties of Ni6Si2B and N... more ABSTRACT The crystal and electronic structures, and the thermodynamic properties of Ni6Si2B and Ni6Ge2B with the Fe2P-type structure have been investigated by means of first principles calculations. The enthalpy of formation at T = 0 K of the Ni6Si2B compound is −46.75 kJ/mol of atoms. The calculated structural parameters and internal parameters of the Ni6Si2B compound are in very good agreement with the experimental data. The ternary compound Ni6Ge2B with the Fe2P-type structure is found to be stable in the Ni–Ge–B system with an enthalpy of formation of −30.79 kJ/mol of atoms. The total electronic densities of states have been computed. First principles calculations have also allowed to show that the Co6Si2B and Pd6Si2B ternary compounds with the Fe2P-type structure are not stable.
Journal of molecular modeling, 2015
Escalating demand for sustainable energy resources, because of the rapid exhaustion of convention... more Escalating demand for sustainable energy resources, because of the rapid exhaustion of conventional energy resources as well as to maintain the environmental level of carbon dioxide (CO2) to avoid its adverse effect on the climate, has led to the exploitation of photovoltaic technology manifold more than ever. In this regard organic materials have attracted great attention on account of demonstrating their potential to harvest solar energy at an affordable rate for photovoltaic technology. 2-vinyl-4,5-dicyanoimidazole (vinazene) is considered as a suitable material over the fullerenes for photovoltaic applications because of its particular chemical and physical nature. In the present study, DFT approaches are employed to provide an exposition of optoelectronic properties of vinazene molecule and molecular crystal. To gain insight into its properties, different forms of exchange correlation energy functional/potential such as LDA, GGA, BLYP, and BL3YP are used. Calculated electronic ...
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Papers by Mazmira Mohamad