TY  - JOUR
AU  - Djurišić, Ivana
AU  - Dražić, Miloš
AU  - Tomović, Aleksandar
AU  - Jovanović, Vladimir P.
AU  - Žikić, Radomir
PY  - 2021
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/1412
AB  - The requirement for controllable frontier orbital energy shift in single-molecule devices based on electronic (tunneling) transport yielded several rules for device design that lean on molecular level pinning to the electrochemical potential of nano-electrodes. We previously found that the pinning (designated as the strong pinning) was the consequence of the bias-induced molecular charge accumulation related to the hybridization of the highest occupied molecular orbital (HOMO) with one of the electrodes. However, in the wide bias range, only "partial" pinning (designated as the weak pinning) happens. In this work, we address the bias-induced shift of molecular orbitals in a weak pinning regime, where no hybridization or covalent bonds with electrodes exist. We found using density functional theory coupled with non-equilibrium Green's functions that the energy shift of frontier molecular orbitals of benzene and nicotine, placed between H-terminated (3, 3) CNTs, in weak pinning regime, is driven only by the electrostatic potential energy of an empty gap. For nicotine, whose HOMO and LUMO (lowest unoccupied molecular orbital) are located on different sides of the gap center, we show that the HOMO-LUMO energy gap changes with bias. We developed a theoretical model of a dielectric in a gap to depict this behavior. Application-wise, we expect that the weak pinning effect would be observable in novel single-molecule sensors based on electronic transport and molecular rectifying as long as the system exhibits a non-resonant behavior, and could serve for molecular gap tuning in single-molecule readout such as DNA, RNA and protein sequencing, or harmful single-molecule detection in gas phase.
PB  - Springer, Dordrecht
T2  - Journal of Nanoparticle Research
T1  - Electrostatically driven energy shift of molecular orbitals of benzene and nicotine in carbon nanotube gaps
IS  - 1
VL  - 23
DO  - 10.1007/s11051-021-05139-y
ER  - 

@article{
author = "Djurišić, Ivana and Dražić, Miloš and Tomović, Aleksandar and Jovanović, Vladimir P. and Žikić, Radomir",
year = "2021",
abstract = "The requirement for controllable frontier orbital energy shift in single-molecule devices based on electronic (tunneling) transport yielded several rules for device design that lean on molecular level pinning to the electrochemical potential of nano-electrodes. We previously found that the pinning (designated as the strong pinning) was the consequence of the bias-induced molecular charge accumulation related to the hybridization of the highest occupied molecular orbital (HOMO) with one of the electrodes. However, in the wide bias range, only "partial" pinning (designated as the weak pinning) happens. In this work, we address the bias-induced shift of molecular orbitals in a weak pinning regime, where no hybridization or covalent bonds with electrodes exist. We found using density functional theory coupled with non-equilibrium Green's functions that the energy shift of frontier molecular orbitals of benzene and nicotine, placed between H-terminated (3, 3) CNTs, in weak pinning regime, is driven only by the electrostatic potential energy of an empty gap. For nicotine, whose HOMO and LUMO (lowest unoccupied molecular orbital) are located on different sides of the gap center, we show that the HOMO-LUMO energy gap changes with bias. We developed a theoretical model of a dielectric in a gap to depict this behavior. Application-wise, we expect that the weak pinning effect would be observable in novel single-molecule sensors based on electronic transport and molecular rectifying as long as the system exhibits a non-resonant behavior, and could serve for molecular gap tuning in single-molecule readout such as DNA, RNA and protein sequencing, or harmful single-molecule detection in gas phase.",
publisher = "Springer, Dordrecht",
journal = "Journal of Nanoparticle Research",
title = "Electrostatically driven energy shift of molecular orbitals of benzene and nicotine in carbon nanotube gaps",
number = "1",
volume = "23",
doi = "10.1007/s11051-021-05139-y"
}

Djurišić, I., Dražić, M., Tomović, A., Jovanović, V. P.,& Žikić, R.. (2021). Electrostatically driven energy shift of molecular orbitals of benzene and nicotine in carbon nanotube gaps. in Journal of Nanoparticle Research
Springer, Dordrecht., 23(1).
https://doi.org/10.1007/s11051-021-05139-y

Djurišić I, Dražić M, Tomović A, Jovanović VP, Žikić R. Electrostatically driven energy shift of molecular orbitals of benzene and nicotine in carbon nanotube gaps. in Journal of Nanoparticle Research. 2021;23(1).
doi:10.1007/s11051-021-05139-y .

Djurišić, Ivana, Dražić, Miloš, Tomović, Aleksandar, Jovanović, Vladimir P., Žikić, Radomir, "Electrostatically driven energy shift of molecular orbitals of benzene and nicotine in carbon nanotube gaps" in Journal of Nanoparticle Research, 23, no. 1 (2021),
https://doi.org/10.1007/s11051-021-05139-y . .

TY  - JOUR
AU  - Djurišić, Ivana
AU  - Dražić, Miloš
AU  - Tomović, Aleksandar
AU  - Spasenović, Marko
AU  - Šljivančanin, Zeljko
AU  - Jovanović, Vladimir P.
AU  - Žikić, Radomir
PY  - 2021
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/1405
AB  - Functionalization of electrodes is a wide-used strategy in various applications ranging from single-molecule sensing and protein sequencing, to ion trapping, to desalination. We demonstrate, employing non-equilibrium Green ' s function formalism combined with density functional theory, that single-species (N, H, S, Cl, F) termination of graphene nanogap electrodes results in a strong in-gap electrostatic field, induced by species-dependent dipoles formed at the electrode ends. Consequently, the field increases or decreases electronic transport through a molecule (benzene) placed in the nanogap by shifting molecular levels by almost 2 eV in respect to the electrode Fermi level via a field effect akin to the one used for field-effect transistors. We also observed the local gating in graphene nanopores terminated with different single-species atoms. Nitrogen-terminated nanogaps (NtNGs) and nanopores (NtNPs) show the strongest effect. The in-gap potential can be transformed from a plateau-like to a saddle-like shape by tailoring NtNG and NtNP size and termination type. In particular, the saddle-like potential is applicable in single-ion trapping and desalination devices.
PB  - Wiley-V C H Verlag Gmbh, Weinheim
T2  - Chemphyschem
T1  - Field Effect and Local Gating in Nitrogen-Terminated Nanopores (NtNP) and Nanogaps (NtNG) in Graphene
EP  - 341
IS  - 3
SP  - 336
VL  - 22
DO  - 10.1002/cphc.202000771
ER  - 

@article{
author = "Djurišić, Ivana and Dražić, Miloš and Tomović, Aleksandar and Spasenović, Marko and Šljivančanin, Zeljko and Jovanović, Vladimir P. and Žikić, Radomir",
year = "2021",
abstract = "Functionalization of electrodes is a wide-used strategy in various applications ranging from single-molecule sensing and protein sequencing, to ion trapping, to desalination. We demonstrate, employing non-equilibrium Green ' s function formalism combined with density functional theory, that single-species (N, H, S, Cl, F) termination of graphene nanogap electrodes results in a strong in-gap electrostatic field, induced by species-dependent dipoles formed at the electrode ends. Consequently, the field increases or decreases electronic transport through a molecule (benzene) placed in the nanogap by shifting molecular levels by almost 2 eV in respect to the electrode Fermi level via a field effect akin to the one used for field-effect transistors. We also observed the local gating in graphene nanopores terminated with different single-species atoms. Nitrogen-terminated nanogaps (NtNGs) and nanopores (NtNPs) show the strongest effect. The in-gap potential can be transformed from a plateau-like to a saddle-like shape by tailoring NtNG and NtNP size and termination type. In particular, the saddle-like potential is applicable in single-ion trapping and desalination devices.",
publisher = "Wiley-V C H Verlag Gmbh, Weinheim",
journal = "Chemphyschem",
title = "Field Effect and Local Gating in Nitrogen-Terminated Nanopores (NtNP) and Nanogaps (NtNG) in Graphene",
pages = "341-336",
number = "3",
volume = "22",
doi = "10.1002/cphc.202000771"
}

Djurišić, I., Dražić, M., Tomović, A., Spasenović, M., Šljivančanin, Z., Jovanović, V. P.,& Žikić, R.. (2021). Field Effect and Local Gating in Nitrogen-Terminated Nanopores (NtNP) and Nanogaps (NtNG) in Graphene. in Chemphyschem
Wiley-V C H Verlag Gmbh, Weinheim., 22(3), 336-341.
https://doi.org/10.1002/cphc.202000771

Djurišić I, Dražić M, Tomović A, Spasenović M, Šljivančanin Z, Jovanović VP, Žikić R. Field Effect and Local Gating in Nitrogen-Terminated Nanopores (NtNP) and Nanogaps (NtNG) in Graphene. in Chemphyschem. 2021;22(3):336-341.
doi:10.1002/cphc.202000771 .

Djurišić, Ivana, Dražić, Miloš, Tomović, Aleksandar, Spasenović, Marko, Šljivančanin, Zeljko, Jovanović, Vladimir P., Žikić, Radomir, "Field Effect and Local Gating in Nitrogen-Terminated Nanopores (NtNP) and Nanogaps (NtNG) in Graphene" in Chemphyschem, 22, no. 3 (2021):336-341,
https://doi.org/10.1002/cphc.202000771 . .