barnali bhattacharya - Academia.edu (original) (raw)
Papers by barnali bhattacharya
Journal of Physics: Conference Series, 2014
ABSTRACT The electronic properties of graphyne and graphdiyne consisting of sp and sp2 hybridized... more ABSTRACT The electronic properties of graphyne and graphdiyne consisting of sp and sp2 hybridized carbon atom have been investigated within the density functional theory (DFT) method. The corresponding changes in the electronic properties due to systematic functionalization by fluorine at different possible sites are reported.
AIP Conference Proceedings, 2017
Density functional theory (DFT) methodology have been used to investigate the global reactivity p... more Density functional theory (DFT) methodology have been used to investigate the global reactivity parameters and non-linear optical properties of pristine C20 and C19X (X = Fe, Co) fullerenes. We find that noticeable structural change takes place in C20 when one of its carbon atoms is substituted with Fe or Co. The energy gap of the doped fullerenes also decreases significantly making these more reactive as compared to C20. The negligible static first hyperpolarizability and zero dipole moment of C20 climb to a considerably higher value even for the presence of single dopant atom. Considering all the studied properties, it may be inferred that the applicability of C20 fullerene as a nanoelectronic and non-linear optical (NLO) material would increase on doping with Fe and Co atom. Specifically, C19Fe would be better among them.
International Journal of Nanoscience, 2017
The stabilities and reactivities of two transition metal ([Formula: see text], Zn)-doped structur... more The stabilities and reactivities of two transition metal ([Formula: see text], Zn)-doped structures of C[Formula: see text] fullerene have been investigated by density functional theory approach. We have observed a noticeable structural change in pristine C[Formula: see text] due to the substitution of one of its carbon atom by Cu or Zn atom. From our findings, it is found that the energy gap of C[Formula: see text]Cu and C[Formula: see text]Zn increases with respect to pristine C[Formula: see text], thus making the two doped fullerenes more stable than their pristine counterpart. The reactivity parameters such as chemical hardness, chemical potential and electrophilicity index for these structures are also studied. Interestingly, our calculations reveal that both the doped fullerenes obey the maximum hardness principle and minimum electrophilicity principle. Also, from the electronic absorption spectra analysis, it can be inferred that the maximum absorption peak of the two heteroa...
Journal of Nanoparticle Research, 2016
AIP Conference Proceedings, 2016
Using density functional theory (DFT) calculations with generalized gradient approximation, the i... more Using density functional theory (DFT) calculations with generalized gradient approximation, the interaction between H2O molecule and (2, 2) graphyne nanotube (GNT) has been investigated. The stable configuration due to the insertion of H2O molecule inside (2, 2) GNT is determined on the basis of binding energy. The band gap of the GNT decreases due to the confinement of H2O molecule. The charge analysis reveals that electrons are shifted from the H2O molecule to the GNT. The electronic property of the GNT is highly influenced by the presence of H2O molecule; thus, we may design a GNT based sensor for the detection of water molecule.
The Journal of Physical Chemistry C, 2016
We have investigated the capacitive behavior of bilayer graphyne and its boron nitride derivative... more We have investigated the capacitive behavior of bilayer graphyne and its boron nitride derivatives by first-principles simulations based on density functional theory, including van der Waals interactions. Our predicted energy and charge storing capacity are greater than those predicted for nanocapacitors based on graphene and hexagonal boron nitride. In the most stable configuration, the two layers are stacked on top of each other, just as in bulk graphyne. The stacking arrangement has a strong effect on the electronic properties of the system: the stable stacking configurations for the graphyne systems are semiconductors with direct band gaps of 0.38 eV and 0.50 eV respectively. Substitutional boron-nitrogen doping provides a way to tune the band gap of the system. The band gap generally increases in presence of the dopants, but the value of the band gap depends on the substitution sites. This suggests that controlled boron nitride doping of graphyne could be a useful and flexible method to build nanoscale electronic and optoelectronic devices.
Journal of Molecular Structure, 2022
Handbook of Graphene, 2019
AIP Advances, 2019
The first-principle calculation with many-body effects explore the electronic and optical propert... more The first-principle calculation with many-body effects explore the electronic and optical properties of newly designed 'graphyne with BP at hexagonal ring' (labeled as BP-yne). Our calculations show that BP-yne surface is a direct band gap semiconductor having band gap greater than pristine graphyne and this band gap value is sufficient to overcome the endothermic character of water-splitting reaction and further indicates its possible photocatalytic activities. The Raman and IR spectra analysis indicates quite different feature compare to its structural analogous 'graphyne with 3BN at ring' which may help to identify it during synthesis. Its optical absorption can be tuned from near-infrared to UV region depending on the polarization of electric field vector. The optical band gap, as well as the strong absorption peak, lies in the near-infrared region (NIR) and this promising trait can be exploited in biomedical arena.
Applied Surface Science, 2019
This study aims to engineer electronic and optical properties of newly designed 'graphyne with XN... more This study aims to engineer electronic and optical properties of newly designed 'graphyne with XN at hexagonal ring' (labeled as XN-ynes, where X = B, Al, Ga). Except BN-yne, all XN-ynes are indirect band gap semiconductors, having larger gap than pristine graphyne. The Raman and IR spectra of XN-yne exhibit quite distinct feature with respect to pristine graphyne and strong Raman and IR line shows regular dependence on group IIIA element, thus may help to detect them during synthesis. The optical band gap calculated by G 0 W 0 and Bethe-Salpeter equation (BSE) approach indicates the possibility of their usage as UV light absorber. The optical band gap is arises from π to π* transition. Not only optical band gap but also the strong absorption peak lies in UV region of electromagnetic spectra that also suggesting their possible use as UV light absorber. This study proposes an important initial step towards the applications of these newly designed XN-ynes.
AIP Conference Proceedings, 2018
Journal of Molecular Modeling, 2018
Density functional theory (DFT) combined with nonequilibrium Green's function (NEGF) formalism ar... more Density functional theory (DFT) combined with nonequilibrium Green's function (NEGF) formalism are used to investigate the effects of substitutional doping by nitrogen and sulfur on transport properties of AGNR-pentalene-AGNR nanojunction. A considerable spin filtering capability in a wide bias range is observed for all systems, which may have potential application in spintronics devices. Moreover, all model devices exhibit a negative differential effect with considerable peak-to-valley ratio. Thus, our findings provide a way to produce multifunctional spintronic devices based on nitrogen and sulfur doped pentalene-AGNR nanojunctions. The underlying mechanism for this interesting behavior was exposed by analyzing the transmission spectrum as well as the electrostatic potential distribution. In addition, a system doped with an odd number of dopant shows a rectifying efficiency comparable to other systems. The above findings strongly imply that such a multifunctional molecular device would be a useful candidate for molecular electronics.
Journal of molecular modeling, Jan 14, 2018
Utilizing first-principles calculations, we studied the electronic and optical properties of C, C... more Utilizing first-principles calculations, we studied the electronic and optical properties of C, CXY, and XY fullerenes (X = B, Al; Y = N, P). These fullerenes are energetically stable, as demonstrated by their negative cohesive energies. The energy gap of C may be tuned by doping, and the BN fullerene was found to have the largest energy gap. All of the fullerenes had finite optical gaps, suggesting that they are optical semiconductors, and they strongly absorb UV radiation, so they could be used in UV light protection devices. They could also be used in solar cells and LEDs due to their low reflectivities. Graphical abstract Possible applications of doped C fullerene.
Dyes and Pigments, 2018
Low-temperature nematic phase in azo functionalised reactive hockey stick mesogens possessing lat... more Low-temperature nematic phase in azo functionalised reactive hockey stick mesogens possessing lateral methyl group,
Carbon, 2019
Highlights 1. BN substitution in graphyne reduces Raman intensity but increases IR intensity 2. W... more Highlights 1. BN substitution in graphyne reduces Raman intensity but increases IR intensity 2. With increasing BN concentration Raman intensity decreases 3. For same doping concentration but different site, there is a blue-shift of the strong Raman peak for ring site compare to chain site 4. High intense high-frequency IR line is the characteristic of BN substituted graphyne 5. Increasing BN concentration decreases the number of IR lines around 1500 cm-1
Advanced Science Letters, 2016
Journal of Molecular Liquids, 2017
New unsymmetrical achiral bent core molecules containing 1,3,4-oxadiazole motif have been synthes... more New unsymmetrical achiral bent core molecules containing 1,3,4-oxadiazole motif have been synthesized. These new bent core molecules resemble hockey-stick shapes due to presence of two arms having different number of the phenyl rings and 4-n-alkyloxy chains. Of these, one arm of the molecule possesses two phenyl rings and 4-n-alkyloxy chain of different length (n=4-8, 10, 12, 14, 16 and 18) while other arm consists of one phenyl ring and fixed 4-n-octyloxy chain. UV-visible and steady state fluorescence in solution and solid thin film were applied in order to characterize the photophysical behaviour of the compounds. The bent core molecules exhibited absorption in the UV region with fluorescence emission in the green wavelength region in dichloromethane and blue fluorescence emission in DMF with a large Stokes shift. It is found that bent core molecules are self-assembled to both Hand J-type aggregates at concentration range (75-50 μM) in dimethylformamide. The phase behaviour of the bent core molecules were characterized by polarized optical microscopy, differential scanning calorimetry and variable temperature powdered X-ray diffraction. The bent core molecule having lower 4-n-butyloxy chain exhibited Iso-N-SmA-DC phase sequence. The dark conglomerate (DC) phase is optically
The Journal of Physical Chemistry C, 2016
The electronic, magnetic, and optical properties of boron- and nitrogen-doped graphyne have been ... more The electronic, magnetic, and optical properties of boron- and nitrogen-doped graphyne have been investigated with various doping positions and concentrations of boron and nitrogen atoms. We have explored how the presence of a single dopant atom changes the conductivity of doped graphyne from the semiconducting to metallic one. The boron atom at the chain site introduces spin polarization which is in the ferromagnetic (FM) ground state for minimal boron concentration and in the antiferromagnetic (AFM) ground state for an increasing number of boron atoms in the unit cell. We have examined the origin of spin polarization which increases with increasing dopant concentration. Our optical spectra show that the interband transition takes place in the low energy regime. Due to the presence of dopant atom, the absorption spectra extend from the infrared region to the UV region and exhibit a strong peak. The reflectivity and energy loss spectra derived the plasmon energy for these systems where the reflectivity di...
Chemical Physics Letters, 2017
Benzthiazoline-2-thione (BTT) and its derivatives are industrially and biologically important het... more Benzthiazoline-2-thione (BTT) and its derivatives are industrially and biologically important heterocyclic organic compounds. Here, we present both experimental and theoretical investigations. The IR and UV spectroscopic measurements unambiguously show the keto-enol tautomerization. Here, for the first time we report spectral changes of BTT in different solvents using quantum chemical calculations and hence reproduce both the hypsochromic and bathochromic shifts in the UV spectra which are sensitive to the nature of hydrogen bonding between solvent and BTT. Our calculations also reveal that the lowest energy transition is associated with a π→π* rather than a n→π* transition suggested to explain experimental results.
Journal of Physics: Conference Series, 2014
ABSTRACT The electronic properties of graphyne and graphdiyne consisting of sp and sp2 hybridized... more ABSTRACT The electronic properties of graphyne and graphdiyne consisting of sp and sp2 hybridized carbon atom have been investigated within the density functional theory (DFT) method. The corresponding changes in the electronic properties due to systematic functionalization by fluorine at different possible sites are reported.
AIP Conference Proceedings, 2017
Density functional theory (DFT) methodology have been used to investigate the global reactivity p... more Density functional theory (DFT) methodology have been used to investigate the global reactivity parameters and non-linear optical properties of pristine C20 and C19X (X = Fe, Co) fullerenes. We find that noticeable structural change takes place in C20 when one of its carbon atoms is substituted with Fe or Co. The energy gap of the doped fullerenes also decreases significantly making these more reactive as compared to C20. The negligible static first hyperpolarizability and zero dipole moment of C20 climb to a considerably higher value even for the presence of single dopant atom. Considering all the studied properties, it may be inferred that the applicability of C20 fullerene as a nanoelectronic and non-linear optical (NLO) material would increase on doping with Fe and Co atom. Specifically, C19Fe would be better among them.
International Journal of Nanoscience, 2017
The stabilities and reactivities of two transition metal ([Formula: see text], Zn)-doped structur... more The stabilities and reactivities of two transition metal ([Formula: see text], Zn)-doped structures of C[Formula: see text] fullerene have been investigated by density functional theory approach. We have observed a noticeable structural change in pristine C[Formula: see text] due to the substitution of one of its carbon atom by Cu or Zn atom. From our findings, it is found that the energy gap of C[Formula: see text]Cu and C[Formula: see text]Zn increases with respect to pristine C[Formula: see text], thus making the two doped fullerenes more stable than their pristine counterpart. The reactivity parameters such as chemical hardness, chemical potential and electrophilicity index for these structures are also studied. Interestingly, our calculations reveal that both the doped fullerenes obey the maximum hardness principle and minimum electrophilicity principle. Also, from the electronic absorption spectra analysis, it can be inferred that the maximum absorption peak of the two heteroa...
Journal of Nanoparticle Research, 2016
AIP Conference Proceedings, 2016
Using density functional theory (DFT) calculations with generalized gradient approximation, the i... more Using density functional theory (DFT) calculations with generalized gradient approximation, the interaction between H2O molecule and (2, 2) graphyne nanotube (GNT) has been investigated. The stable configuration due to the insertion of H2O molecule inside (2, 2) GNT is determined on the basis of binding energy. The band gap of the GNT decreases due to the confinement of H2O molecule. The charge analysis reveals that electrons are shifted from the H2O molecule to the GNT. The electronic property of the GNT is highly influenced by the presence of H2O molecule; thus, we may design a GNT based sensor for the detection of water molecule.
The Journal of Physical Chemistry C, 2016
We have investigated the capacitive behavior of bilayer graphyne and its boron nitride derivative... more We have investigated the capacitive behavior of bilayer graphyne and its boron nitride derivatives by first-principles simulations based on density functional theory, including van der Waals interactions. Our predicted energy and charge storing capacity are greater than those predicted for nanocapacitors based on graphene and hexagonal boron nitride. In the most stable configuration, the two layers are stacked on top of each other, just as in bulk graphyne. The stacking arrangement has a strong effect on the electronic properties of the system: the stable stacking configurations for the graphyne systems are semiconductors with direct band gaps of 0.38 eV and 0.50 eV respectively. Substitutional boron-nitrogen doping provides a way to tune the band gap of the system. The band gap generally increases in presence of the dopants, but the value of the band gap depends on the substitution sites. This suggests that controlled boron nitride doping of graphyne could be a useful and flexible method to build nanoscale electronic and optoelectronic devices.
Journal of Molecular Structure, 2022
Handbook of Graphene, 2019
AIP Advances, 2019
The first-principle calculation with many-body effects explore the electronic and optical propert... more The first-principle calculation with many-body effects explore the electronic and optical properties of newly designed 'graphyne with BP at hexagonal ring' (labeled as BP-yne). Our calculations show that BP-yne surface is a direct band gap semiconductor having band gap greater than pristine graphyne and this band gap value is sufficient to overcome the endothermic character of water-splitting reaction and further indicates its possible photocatalytic activities. The Raman and IR spectra analysis indicates quite different feature compare to its structural analogous 'graphyne with 3BN at ring' which may help to identify it during synthesis. Its optical absorption can be tuned from near-infrared to UV region depending on the polarization of electric field vector. The optical band gap, as well as the strong absorption peak, lies in the near-infrared region (NIR) and this promising trait can be exploited in biomedical arena.
Applied Surface Science, 2019
This study aims to engineer electronic and optical properties of newly designed 'graphyne with XN... more This study aims to engineer electronic and optical properties of newly designed 'graphyne with XN at hexagonal ring' (labeled as XN-ynes, where X = B, Al, Ga). Except BN-yne, all XN-ynes are indirect band gap semiconductors, having larger gap than pristine graphyne. The Raman and IR spectra of XN-yne exhibit quite distinct feature with respect to pristine graphyne and strong Raman and IR line shows regular dependence on group IIIA element, thus may help to detect them during synthesis. The optical band gap calculated by G 0 W 0 and Bethe-Salpeter equation (BSE) approach indicates the possibility of their usage as UV light absorber. The optical band gap is arises from π to π* transition. Not only optical band gap but also the strong absorption peak lies in UV region of electromagnetic spectra that also suggesting their possible use as UV light absorber. This study proposes an important initial step towards the applications of these newly designed XN-ynes.
AIP Conference Proceedings, 2018
Journal of Molecular Modeling, 2018
Density functional theory (DFT) combined with nonequilibrium Green's function (NEGF) formalism ar... more Density functional theory (DFT) combined with nonequilibrium Green's function (NEGF) formalism are used to investigate the effects of substitutional doping by nitrogen and sulfur on transport properties of AGNR-pentalene-AGNR nanojunction. A considerable spin filtering capability in a wide bias range is observed for all systems, which may have potential application in spintronics devices. Moreover, all model devices exhibit a negative differential effect with considerable peak-to-valley ratio. Thus, our findings provide a way to produce multifunctional spintronic devices based on nitrogen and sulfur doped pentalene-AGNR nanojunctions. The underlying mechanism for this interesting behavior was exposed by analyzing the transmission spectrum as well as the electrostatic potential distribution. In addition, a system doped with an odd number of dopant shows a rectifying efficiency comparable to other systems. The above findings strongly imply that such a multifunctional molecular device would be a useful candidate for molecular electronics.
Journal of molecular modeling, Jan 14, 2018
Utilizing first-principles calculations, we studied the electronic and optical properties of C, C... more Utilizing first-principles calculations, we studied the electronic and optical properties of C, CXY, and XY fullerenes (X = B, Al; Y = N, P). These fullerenes are energetically stable, as demonstrated by their negative cohesive energies. The energy gap of C may be tuned by doping, and the BN fullerene was found to have the largest energy gap. All of the fullerenes had finite optical gaps, suggesting that they are optical semiconductors, and they strongly absorb UV radiation, so they could be used in UV light protection devices. They could also be used in solar cells and LEDs due to their low reflectivities. Graphical abstract Possible applications of doped C fullerene.
Dyes and Pigments, 2018
Low-temperature nematic phase in azo functionalised reactive hockey stick mesogens possessing lat... more Low-temperature nematic phase in azo functionalised reactive hockey stick mesogens possessing lateral methyl group,
Carbon, 2019
Highlights 1. BN substitution in graphyne reduces Raman intensity but increases IR intensity 2. W... more Highlights 1. BN substitution in graphyne reduces Raman intensity but increases IR intensity 2. With increasing BN concentration Raman intensity decreases 3. For same doping concentration but different site, there is a blue-shift of the strong Raman peak for ring site compare to chain site 4. High intense high-frequency IR line is the characteristic of BN substituted graphyne 5. Increasing BN concentration decreases the number of IR lines around 1500 cm-1
Advanced Science Letters, 2016
Journal of Molecular Liquids, 2017
New unsymmetrical achiral bent core molecules containing 1,3,4-oxadiazole motif have been synthes... more New unsymmetrical achiral bent core molecules containing 1,3,4-oxadiazole motif have been synthesized. These new bent core molecules resemble hockey-stick shapes due to presence of two arms having different number of the phenyl rings and 4-n-alkyloxy chains. Of these, one arm of the molecule possesses two phenyl rings and 4-n-alkyloxy chain of different length (n=4-8, 10, 12, 14, 16 and 18) while other arm consists of one phenyl ring and fixed 4-n-octyloxy chain. UV-visible and steady state fluorescence in solution and solid thin film were applied in order to characterize the photophysical behaviour of the compounds. The bent core molecules exhibited absorption in the UV region with fluorescence emission in the green wavelength region in dichloromethane and blue fluorescence emission in DMF with a large Stokes shift. It is found that bent core molecules are self-assembled to both Hand J-type aggregates at concentration range (75-50 μM) in dimethylformamide. The phase behaviour of the bent core molecules were characterized by polarized optical microscopy, differential scanning calorimetry and variable temperature powdered X-ray diffraction. The bent core molecule having lower 4-n-butyloxy chain exhibited Iso-N-SmA-DC phase sequence. The dark conglomerate (DC) phase is optically
The Journal of Physical Chemistry C, 2016
The electronic, magnetic, and optical properties of boron- and nitrogen-doped graphyne have been ... more The electronic, magnetic, and optical properties of boron- and nitrogen-doped graphyne have been investigated with various doping positions and concentrations of boron and nitrogen atoms. We have explored how the presence of a single dopant atom changes the conductivity of doped graphyne from the semiconducting to metallic one. The boron atom at the chain site introduces spin polarization which is in the ferromagnetic (FM) ground state for minimal boron concentration and in the antiferromagnetic (AFM) ground state for an increasing number of boron atoms in the unit cell. We have examined the origin of spin polarization which increases with increasing dopant concentration. Our optical spectra show that the interband transition takes place in the low energy regime. Due to the presence of dopant atom, the absorption spectra extend from the infrared region to the UV region and exhibit a strong peak. The reflectivity and energy loss spectra derived the plasmon energy for these systems where the reflectivity di...
Chemical Physics Letters, 2017
Benzthiazoline-2-thione (BTT) and its derivatives are industrially and biologically important het... more Benzthiazoline-2-thione (BTT) and its derivatives are industrially and biologically important heterocyclic organic compounds. Here, we present both experimental and theoretical investigations. The IR and UV spectroscopic measurements unambiguously show the keto-enol tautomerization. Here, for the first time we report spectral changes of BTT in different solvents using quantum chemical calculations and hence reproduce both the hypsochromic and bathochromic shifts in the UV spectra which are sensitive to the nature of hydrogen bonding between solvent and BTT. Our calculations also reveal that the lowest energy transition is associated with a π→π* rather than a n→π* transition suggested to explain experimental results.