Enhanced sensitivity of MoSe2 monolayer for gas adsorption induced by electric field

Research output: Contribution to journalArticleScientificpeer-review

Researchers

Research units

  • Nanjing Tech University
  • Queensland Univ Technol, Queensland University of Technology (QUT), Sch Chem, Phys & Mech Engn Fac
  • Helmholtz Zentrum Dresden Rossendorf, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Helmholtz Association, Inst Ion Beam Phys & Mat Res
  • Southeast Univ, Southeast University - China, SEU FEI Nanopico Ctr, Key Lab MEMS, Minist Educ,Collaborat Innovat Ctr Micro Nano Fab

Abstract

According to recent studies, gas sensors based on MoSe2 have better detection performance than graphene-based sensors, especially for N-based gas molecules, but the reason for that is not fully understood at the microscopic level. Here, we investigate the adsorption of CO, CO2, NH3, NO and NO2 gas molecules on MoSe2 monolayer by the density functional theory calculations. Our results reveal that indeed MoSe2 monolayer is more sensitive to adsorption of N-containing gas molecules than C-containing, which can be attributed to the distinct charge transfer between the gas molecules and MoSe2. The conductance was further calculated using the nonequilibrium Green's function (NEGF) formalism. The reduced conductance was found for NH3 and NO2 adsorbed MoSe2, consistent with the high sensitivity of MoSe2 for NH3 and NO2 molecules in the recent experiments. In addition, the adsorption sensitivity can significantly be improved by an external electric field, which implies the controllable gas detection by MoSe2. The magnetic moments of adsorbed NO and NO2 molecules can also be effectively modulated by the field-sensitive charge transfer. Our results not only give microscopic explanations to the recent experiments, but also suggest using MoSe2 as a promising material for controlled gas sensing.

Details

Original languageEnglish
Article number445301
Number of pages8
JournalJournal of physics: Condensed matter
Volume31
Issue number44
Publication statusPublished - 6 Nov 2019
MoE publication typeA1 Journal article-refereed

    Research areas

  • transition metal dichalcogenides, gas sensor, density functional theory calculations, electric field, BAND-STRUCTURE MODULATION, TOTAL-ENERGY CALCULATIONS, CARBON NANOTUBES, OZONE MOLECULES, DFT, BEHAVIOR, CO

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