TY - JOUR

T1 - Gas Sensing Properties of Graphene/MoS/Graphene Lateral Heterostructure

T2 - A First Principles Investigation

AU - Ghayyem, Forough

AU - Kiakojouri, Ali

AU - Frank, Irmgard

AU - Nadimi, Ebrahim

N1 - Publisher Copyright: © 2001-2012 IEEE.

PY - 2024/10/1

Y1 - 2024/10/1

N2 - 2-D materials are promising candidates for gas sensing applications due to their high surface to volume ratio. However, graphene and MoS2, two prominent members of these materials, show little sensitivity toward gas molecules such as NH3, CO2, and H2O. In this work, the gas sensing properties of graphene and MoS2 lateral heterostructures are investigated theoretically using density functional theory (DFT) in combination with a non-equilibrium Green's function (NEGF) formalism. The heterostructure consists of a MoS2 part, which is sandwiched between two graphene sides. There are distinct interfaces between MoS2 and graphene, whereby C-Mo and C-S bonds connect the two materials. The results reveal that CO2 and H2O are weakly adsorbed on different parts of the heterostructure, while NH3 molecules are strongly adsorbed on the C-Mo interface with an energy equal to -1.233 eV. Further analyses reveal that only the adsorbed NH3 at the C-Mo surface leads to significant changes in the electronic structure, even in an atmospheric environment, where O2 molecules are pre-adsorbed at the interface. The planar average of electrostatic potential and the calculated currents at ±0.5 V applied voltages reveal that the Schottky barrier at C-Mo graphene/MoS2 interface is very sensitive to the adsorption of NH3 gas molecule.

AB - 2-D materials are promising candidates for gas sensing applications due to their high surface to volume ratio. However, graphene and MoS2, two prominent members of these materials, show little sensitivity toward gas molecules such as NH3, CO2, and H2O. In this work, the gas sensing properties of graphene and MoS2 lateral heterostructures are investigated theoretically using density functional theory (DFT) in combination with a non-equilibrium Green's function (NEGF) formalism. The heterostructure consists of a MoS2 part, which is sandwiched between two graphene sides. There are distinct interfaces between MoS2 and graphene, whereby C-Mo and C-S bonds connect the two materials. The results reveal that CO2 and H2O are weakly adsorbed on different parts of the heterostructure, while NH3 molecules are strongly adsorbed on the C-Mo interface with an energy equal to -1.233 eV. Further analyses reveal that only the adsorbed NH3 at the C-Mo surface leads to significant changes in the electronic structure, even in an atmospheric environment, where O2 molecules are pre-adsorbed at the interface. The planar average of electrostatic potential and the calculated currents at ±0.5 V applied voltages reveal that the Schottky barrier at C-Mo graphene/MoS2 interface is very sensitive to the adsorption of NH3 gas molecule.

KW - Ammonia

KW - density functional theory (DFT)

KW - gas sensing

KW - graphene/M S heterostructure

KW - molybdenum disulfide (MoS)

KW - non-equilibrium greens function (NEGF)

UR - http://www.scopus.com/inward/record.url?scp=85205813371&partnerID=8YFLogxK

U2 - 10.1109/JSEN.2024.3468168

DO - 10.1109/JSEN.2024.3468168

M3 - Article

AN - SCOPUS:85205813371

VL - 24

SP - 36334

EP - 36341

JO - IEEE sensors journal

JF - IEEE sensors journal

SN - 1530-437X

IS - 22

ER -