Details
Original language | English |
---|---|
Article number | 150454 |
Journal | Applied Surface Science |
Volume | 565 |
Early online date | 1 Jul 2021 |
Publication status | Published - 1 Nov 2021 |
Abstract
Two dimensional nanomaterials are promising for gas sensing applications due to their large surface to volume ratio. Recent studies show that the sensitivity of pristine graphene, the most prominent two-dimensional material, can be improved by several methods such as doping, decoration and combination with other two-dimensional materials. In the present work a two-dimensional graphene/h-BN multi-heterostructure, in the form of G/h-BN/G/h-BN/G, is proposed for gas sensing applications, which is expected to outperform pristine graphene devices. The adsorption energies and charge transfer for H2O, NH3 and NO2 molecules are investigated at the density functional level of theory. The presence of two insulating h-BN layers induces potential barriers for charge carriers and changes the current mechanism to the quantum tunneling regime, which is highly sensitive to the modulation of the potential barrier due to the adsorbed molecules. A first principles method based on non-equilibrium Green's function formalism is employed for the calculation of the device current in various environments. The proposed device shows little sensitivity toward H2O but it is very sensitive toward NH3 and NO2. Moreover, NO2 adsorption increases the device current, while NH3 adsorption reduces the current, a property which can result in a selective sensing of these two gas molecules.
Keywords
- Density functional theory (DFT), Gas sensor, Graphene, Hexagonal boron nitride (h-BN), Non-equilibrium Green's function (NEGF), Two-dimensional heterostructure
ASJC Scopus subject areas
- Chemistry(all)
- Physics and Astronomy(all)
- Condensed Matter Physics
- Physics and Astronomy(all)
- Physics and Astronomy(all)
- Surfaces and Interfaces
- Materials Science(all)
- Surfaces, Coatings and Films
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In: Applied Surface Science, Vol. 565, 150454, 01.11.2021.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Gas sensing properties of a two-dimensional graphene/h-BN multi-heterostructure toward H2O, NH3 and NO2
T2 - A first principles study
AU - Hakimi Raaad, Naser
AU - Manavizadeh, Negin
AU - Frank, Irmgard
AU - Nadimi, Ebrahim
PY - 2021/11/1
Y1 - 2021/11/1
N2 - Two dimensional nanomaterials are promising for gas sensing applications due to their large surface to volume ratio. Recent studies show that the sensitivity of pristine graphene, the most prominent two-dimensional material, can be improved by several methods such as doping, decoration and combination with other two-dimensional materials. In the present work a two-dimensional graphene/h-BN multi-heterostructure, in the form of G/h-BN/G/h-BN/G, is proposed for gas sensing applications, which is expected to outperform pristine graphene devices. The adsorption energies and charge transfer for H2O, NH3 and NO2 molecules are investigated at the density functional level of theory. The presence of two insulating h-BN layers induces potential barriers for charge carriers and changes the current mechanism to the quantum tunneling regime, which is highly sensitive to the modulation of the potential barrier due to the adsorbed molecules. A first principles method based on non-equilibrium Green's function formalism is employed for the calculation of the device current in various environments. The proposed device shows little sensitivity toward H2O but it is very sensitive toward NH3 and NO2. Moreover, NO2 adsorption increases the device current, while NH3 adsorption reduces the current, a property which can result in a selective sensing of these two gas molecules.
AB - Two dimensional nanomaterials are promising for gas sensing applications due to their large surface to volume ratio. Recent studies show that the sensitivity of pristine graphene, the most prominent two-dimensional material, can be improved by several methods such as doping, decoration and combination with other two-dimensional materials. In the present work a two-dimensional graphene/h-BN multi-heterostructure, in the form of G/h-BN/G/h-BN/G, is proposed for gas sensing applications, which is expected to outperform pristine graphene devices. The adsorption energies and charge transfer for H2O, NH3 and NO2 molecules are investigated at the density functional level of theory. The presence of two insulating h-BN layers induces potential barriers for charge carriers and changes the current mechanism to the quantum tunneling regime, which is highly sensitive to the modulation of the potential barrier due to the adsorbed molecules. A first principles method based on non-equilibrium Green's function formalism is employed for the calculation of the device current in various environments. The proposed device shows little sensitivity toward H2O but it is very sensitive toward NH3 and NO2. Moreover, NO2 adsorption increases the device current, while NH3 adsorption reduces the current, a property which can result in a selective sensing of these two gas molecules.
KW - Density functional theory (DFT)
KW - Gas sensor
KW - Graphene
KW - Hexagonal boron nitride (h-BN)
KW - Non-equilibrium Green's function (NEGF)
KW - Two-dimensional heterostructure
UR - http://www.scopus.com/inward/record.url?scp=85109208988&partnerID=8YFLogxK
U2 - 10.1016/j.apsusc.2021.150454
DO - 10.1016/j.apsusc.2021.150454
M3 - Article
AN - SCOPUS:85109208988
VL - 565
JO - Applied Surface Science
JF - Applied Surface Science
SN - 0169-4332
M1 - 150454
ER -