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Trung N, Hossain MI, Alam MI, Ando A, Kitakami O, Kikuchi N, Takaoka T, Sainoo Y, Arafune R, Komeda T. In Situ Study of Molecular Doping of Chlorine on MoS 2 Field Effect Transistor Device in Ultrahigh Vacuum Conditions. ACS OMEGA 2020; 5:28108-28115. [PMID: 33163793 PMCID: PMC7643195 DOI: 10.1021/acsomega.0c03741] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 10/08/2020] [Indexed: 06/11/2023]
Abstract
We report a precise measurement of the sensor behavior of the field effect transistor (FET) formed with the MoS2 channel when the channel part is exposed to Cl2 gas. The gas exposure and the electrical measurement of the MoS2 FET were executed with in situ ultrahigh-vacuum (UHV) conditions in which the surface analysis techniques were equipped. This makes it possible to detect how much sensitivity the MoS2 FET can provide and understand the surface properties. With the Cl2 gas exposure to the channel, the plot of the drain current versus the gate voltage (I d-V g curve) shifts monotonically toward the positive direction of V g, suggesting that the adsorbate acts as an electron acceptor. The I d-V g shifts are numerically estimated by measuring the onset of I d (threshold voltage, V th) and the mobility as a function of the dosing amounts of the Cl2 gas. The behaviors of both the V th shift and the mobility with the Cl2 dosing amount can be fitted with the Langmuir adsorption kinetics, which is typically seen in the uptake curve of molecule adsorption onto well-defined surfaces. This can be accounted for by a model where an impinging molecule occupies an empty site with a certain probability, and each adsorbate receives a certain amount of negative charge from the MoS2 surface up to the monolayer coverage. The charge transfer makes the V th shifts. In addition, the mobility is reduced by the enhancement of the Coulomb scattering for the electron flow in the MoS2 channel by the accumulated charge. From the thermal desorption spectroscopy (TDS) measurement and density functional theory (DFT) calculations, we concluded that the adsorbate that is responsible for the change of the FET property is the Cl atom that is dissociated from the Cl2 molecule. The monotonic shift of V th with the coverage suggests that the MoS2 device sensor has a good sensitivity to detect 10-3 monolayers (ML) of adsorption corresponding to the ppb level sensor with an activation time of 1 s.
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Affiliation(s)
- Nguyen
Tat Trung
- Department
of Chemistry, Graduate School of Science, Tohoku University, 6-3, Aramaki-Aza-Aoba, Aoba-Ku, Sendai 980-8578, Japan
| | - Mohammad Ikram Hossain
- Department
of Chemistry, Graduate School of Science, Tohoku University, 6-3, Aramaki-Aza-Aoba, Aoba-Ku, Sendai 980-8578, Japan
| | - Md Iftekharul Alam
- Department
of Chemistry, Graduate School of Science, Tohoku University, 6-3, Aramaki-Aza-Aoba, Aoba-Ku, Sendai 980-8578, Japan
| | - Atsushi Ando
- Nanoelectronics
Research Institute, National Institute of
Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan
| | - Osamu Kitakami
- Institute
of Multidisciplinary Research for Advanced Materials (IMRAM, Tagen), Tohoku University, 2-1-1, Katahira, Aoba-Ku, Sendai 980-0877, Japan
- Center
for Spintronics Research Network, Tohoku
University, Sendai 980-0877, Japan
| | - Nobuaki Kikuchi
- Institute
of Multidisciplinary Research for Advanced Materials (IMRAM, Tagen), Tohoku University, 2-1-1, Katahira, Aoba-Ku, Sendai 980-0877, Japan
- Center
for Spintronics Research Network, Tohoku
University, Sendai 980-0877, Japan
| | - Tsuyoshi Takaoka
- Institute
of Multidisciplinary Research for Advanced Materials (IMRAM, Tagen), Tohoku University, 2-1-1, Katahira, Aoba-Ku, Sendai 980-0877, Japan
| | - Yasuyuki Sainoo
- Institute
of Multidisciplinary Research for Advanced Materials (IMRAM, Tagen), Tohoku University, 2-1-1, Katahira, Aoba-Ku, Sendai 980-0877, Japan
| | - Ryuichi Arafune
- International
Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 304-0044, Japan
| | - Tadahiro Komeda
- Institute
of Multidisciplinary Research for Advanced Materials (IMRAM, Tagen), Tohoku University, 2-1-1, Katahira, Aoba-Ku, Sendai 980-0877, Japan
- Center
for Spintronics Research Network, Tohoku
University, Sendai 980-0877, Japan
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