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Title: Towards intrinsic MoS{sub 2} devices for high performance arsenite sensing

Abstract

Molybdenum disulphide (MoS{sub 2}) is one of the most attractive two dimensional materials other than graphene, and the exceptional properties make it a promising candidate for bio/chemical sensing. Nevertheless, intrinsic properties and sensing performances of MoS{sub 2} are easily masked by the presence of the Schottky barrier (SB) at source/drain electrodes, and its impact on MoS{sub 2} sensors remains unclear. Here, we systematically investigated the influence of the SB on MoS{sub 2} sensors, revealing the sensing mechanism of intrinsic MoS{sub 2}. By utilizing a small work function metal, Ti, to reduce the SB, excellent electrical properties of this 2D material were yielded with 2–3 times enhanced sensitivity. We experimentally demonstrated that the sensitivity of MoS{sub 2} is superior to that of graphene. Intrinsic MoS{sub 2} was able to realize rapid detection of arsenite down to 0.1 ppb without the influence of large SB, which is two-fold lower than the World Health Organization (WHO) tolerance level and better than the detection limit of recently reported arsenite sensors. Additionally, accurately discriminating target molecules is a great challenge for sensors based on 2D materials. This work demonstrates MoS{sub 2} sensors encapsulated with ionophore film which only allows certain types of molecules to selectively permeatemore » through it. As a result, multiplex ion detection with superb selectivity was realized. Our results show prominent advantages of intrinsic MoS{sub 2} as a sensing material.« less

Authors:
 [1]; ; ; ; ;  [2]
  1. Department of Precision Instruments, State Key Laboratory of Precision Measurement Technology and Instruments, Tsinghua University, Beijing 100084 (China)
  2. College of Information and Control Engineering, China University of Petroleum (East China), Qingdao 266580 (China)
Publication Date:
OSTI Identifier:
22594362
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 109; Journal Issue: 6; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ELECTRICAL PROPERTIES; ELECTRODES; EQUIPMENT; FILMS; GRAPHENE; ION DETECTION; IONS; MOLECULES; MOLYBDENUM SULFIDES; PERFORMANCE; SCHOTTKY BARRIER DIODES; SENSITIVITY; SENSORS; SILICON OXIDES; TWO-DIMENSIONAL CALCULATIONS; WORK FUNCTIONS

Citation Formats

Li, Peng, E-mail: pengli@mail.tsinghua.edu.cn, E-mail: dzzhang@upc.edu.cn, Zhang, Dongzhi, E-mail: pengli@mail.tsinghua.edu.cn, E-mail: dzzhang@upc.edu.cn, Sun, Yan'e, Chang, Hongyan, Liu, Jingjing, and Yin, Nailiang. Towards intrinsic MoS{sub 2} devices for high performance arsenite sensing. United States: N. p., 2016. Web. doi:10.1063/1.4960967.
Li, Peng, E-mail: pengli@mail.tsinghua.edu.cn, E-mail: dzzhang@upc.edu.cn, Zhang, Dongzhi, E-mail: pengli@mail.tsinghua.edu.cn, E-mail: dzzhang@upc.edu.cn, Sun, Yan'e, Chang, Hongyan, Liu, Jingjing, & Yin, Nailiang. Towards intrinsic MoS{sub 2} devices for high performance arsenite sensing. United States. doi:10.1063/1.4960967.
Li, Peng, E-mail: pengli@mail.tsinghua.edu.cn, E-mail: dzzhang@upc.edu.cn, Zhang, Dongzhi, E-mail: pengli@mail.tsinghua.edu.cn, E-mail: dzzhang@upc.edu.cn, Sun, Yan'e, Chang, Hongyan, Liu, Jingjing, and Yin, Nailiang. Mon . "Towards intrinsic MoS{sub 2} devices for high performance arsenite sensing". United States. doi:10.1063/1.4960967.
@article{osti_22594362,
title = {Towards intrinsic MoS{sub 2} devices for high performance arsenite sensing},
author = {Li, Peng, E-mail: pengli@mail.tsinghua.edu.cn, E-mail: dzzhang@upc.edu.cn and Zhang, Dongzhi, E-mail: pengli@mail.tsinghua.edu.cn, E-mail: dzzhang@upc.edu.cn and Sun, Yan'e and Chang, Hongyan and Liu, Jingjing and Yin, Nailiang},
abstractNote = {Molybdenum disulphide (MoS{sub 2}) is one of the most attractive two dimensional materials other than graphene, and the exceptional properties make it a promising candidate for bio/chemical sensing. Nevertheless, intrinsic properties and sensing performances of MoS{sub 2} are easily masked by the presence of the Schottky barrier (SB) at source/drain electrodes, and its impact on MoS{sub 2} sensors remains unclear. Here, we systematically investigated the influence of the SB on MoS{sub 2} sensors, revealing the sensing mechanism of intrinsic MoS{sub 2}. By utilizing a small work function metal, Ti, to reduce the SB, excellent electrical properties of this 2D material were yielded with 2–3 times enhanced sensitivity. We experimentally demonstrated that the sensitivity of MoS{sub 2} is superior to that of graphene. Intrinsic MoS{sub 2} was able to realize rapid detection of arsenite down to 0.1 ppb without the influence of large SB, which is two-fold lower than the World Health Organization (WHO) tolerance level and better than the detection limit of recently reported arsenite sensors. Additionally, accurately discriminating target molecules is a great challenge for sensors based on 2D materials. This work demonstrates MoS{sub 2} sensors encapsulated with ionophore film which only allows certain types of molecules to selectively permeate through it. As a result, multiplex ion detection with superb selectivity was realized. Our results show prominent advantages of intrinsic MoS{sub 2} as a sensing material.},
doi = {10.1063/1.4960967},
journal = {Applied Physics Letters},
number = 6,
volume = 109,
place = {United States},
year = {Mon Aug 08 00:00:00 EDT 2016},
month = {Mon Aug 08 00:00:00 EDT 2016}
}
  • Here, we report a new strategy for fabricating 2D/2D low-resistance ohmic contacts for a variety of transition metal dichalcogenides (TMDs) using van der Waals assembly of substitutionally doped TMDs as drain/source contacts and TMDs with no intentional doping as channel materials. We demonstrate that few-layer WSe 2 field-effect transistors (FETs) with 2D/2D contacts exhibit low contact resistances of ~0.3 kΩ μm, high on/off ratios up to >10 9, and high drive currents exceeding 320 μA μm –1. These favorable characteristics are combined with a two-terminal field-effect hole mobility μ FE ≈ 2 × 10 2 cm 2 V –1 smore » –1 at room temperature, which increases to >2 × 10 3 cm 2 V –1 s –1 at cryogenic temperatures. We observe a similar performance also in MoS 2 and MoSe 2 FETs with 2D/2D drain and source contacts. The 2D/2D low-resistance ohmic contacts presented here represent a new device paradigm that overcomes a significant bottleneck in the performance of TMDs and a wide variety of other 2D materials as the channel materials in postsilicon electronics.« less
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  • The enhanced photocatalytic performance of various MoS{sub 2}-based nanomaterials has recently been observed, but the role of monolayer MoS{sub 2} is still not well elucidated at the electronic level. Herein, focusing on a model system, hybrid MoS{sub 2}/SnO{sub 2} nanocomposite, we first present a theoretical elucidation of the dual role of monolayer MoS{sub 2} as a sensitizer and a co-catalyst by performing density functional theory calculations. It is demonstrated that a type-II, staggered, band alignment of ∼0.49 eV exists between monolayer MoS{sub 2} and SnO{sub 2} with the latter possessing the higher electron affinity, or work function, leading to the robustmore » separation of photoexcited charge carriers between the two constituents. Under irradiation, the electrons are excited from Mo 4d orbitals to SnO{sub 2}, thus enhancing the reduction activity of latter, indicating that the monolayer MoS{sub 2} is an effective sensitizer. Moreover, the Mo atoms, which are catalytically inert in isolated monolayer MoS{sub 2}, turn into catalytic active sites, making the monolayer MoS{sub 2} to be a highly active co-catalyst in the composite. The dual role of monolayer MoS{sub 2} is expected to arise in other MoS{sub 2}-semiconductor nanocomposites. The calculated absorption spectra can be rationalized by available experimental results. These findings provide theoretical evidence supporting the experimental reports and pave the way for developing highly efficient MoS{sub 2}-based photocatalysts.« less
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