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 -