Energy level modulation of MoS<sub>2</sub>monolayers by halide doping for an enhanced hydrogen evolution reaction

Lim, Jungmoon; Byeon, Junsung; Park, Kyungho; Hong, John; Pak, Sangyeon; Cha, SeungNam

doi:10.1039/d2ta06105h

Cited by 10 publications

(13 citation statements)

References 49 publications

(98 reference statements)

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“…This iodine doping can occur because of the higher electronegativity of iodine compared to that of Cu, [18] similar doping mechanism with previously reported metal-ion-doped CuS. [19][20][21][22][23][24][25][26] The CuS electrode, which is covellite and nanosheet structure, was synthesized based on a room-temperature sulfur activation method which is reported at our previous article. [27] The thickness of CuS was controlled to be 20 % 40 nm which is optimized conditions with a low sheet resistance (Figure 1b).…”

Section: Resultssupporting

confidence: 73%

Electronic Modulation of Semimetallic Electrode for 2D van der Waals Devices

et al. 2023

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The 2D semimetallic electrodes have been employed to show outstanding contact properties with 2D semiconducting transition‐metal dichalcogenides (TMDCs) channel, leading to large enhancement of 2D transistor and phototransistor performance. Herein, an innovative concept is established for a unique 2D semimetallic electrode‐2D TMDC channel (2D–2D) device configuration where the electronic structures of 2D semimetallic electrodes are systematically modulated to improve the contact properties with 2D monolayer molybdenum disulfide (MoS2) channel. The 2D semimetallic copper sulfide (CuS) electrodes are doped with iodine atoms by a direct exposure of iodine gas. The contact properties and charge‐transport behavior in the 2D–2D field‐effect transistors (FETs) are highly improved, which is attributed to the favorable energy band alignment and associated material properties between the iodine‐doped CuS (CuS–I) electrodes and 2D channel. The 2D–2D FETs show a high on current, high on/off ratio, and twofold improvement in mobility. Furthermore, 2D–2D phototransistors and flexible/transparent photodetectors are fabricated using the CuS–I/MoS2, which also performed outstanding photoresponsivity characteristics and mechanical durability under external bending strain conditions. These findings demonstrate a promising pathway that under the 2D–2D configuration, the electronic modulation by the iodine atoms may enable the development of future 2D electronic applications.

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Section: Resultssupporting

confidence: 73%

Electronic Modulation of Semimetallic Electrode for 2D van der Waals Devices

et al. 2023

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“…In the Raman spectra (Figure c), the A 1g Raman mode of the H 2 S-treated MoS 2 exhibited prominent red-shifted, while the E 2g Raman mode showed negligible shift. The red-shift of the A 1g mode is associated with the increasing charge carrier density, and the E 2g mode is more sensitive to the strain effect on the MoS 2 crystals. ,− The whole spectrum of Raman spectra is given in Figure S1, which reveals that there is no other distinctive peak after the H 2 S treatment. We further verified the optical properties of the H 2 S-treated MoS 2 by PL measurement.…”

Section: Resultsmentioning

confidence: 99%

Achieving Adsorbate-Free Monolayered MoS₂ Field Effect Transistors by Controlled Surface Gas Treatment

Byeon,

Eom,

Kim

et al. 2024

ACS Appl. Electron. Mater.

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Monolayered transition metal dichalcogenides (TMDCs) possess a highly sensitive nature to external elements, particularly adsorbed molecules on the surface such as H 2 O or O 2 molecules, due to their atomically thin structure. In this sense, it is important to develop a strategy to obtain a pristine surface of 2D TMDCs for the successful and reliable fabrication of a device with their originally intended functions. Here, we suggest a facile strategy of surface treatment to effectively eliminate the influence of adsorbed molecules in the electrical performance of the monolayered MoS 2 FETs via surface treatment using highly reactive H 2 S gas at room temperature. We demonstrated increased carrier concentration of absorbate-free MoS 2 using various spectroscopy and electrical measurements. The H 2 S-treated MoS 2 FETs showed a 171% increase in on-current level and reduced hysteresis window compared to pristine MoS 2 FETs. Moreover, the H 2 S-treated MoS 2 FETs exhibit increased field effect mobility. Additionally, we verified that the clean interface of MoS 2 is preserved through dry passivation of MoS 2 FETs. This unique room temperature surface treatment strategy allows the development of highly conductive MoS 2 FETs with a clean surface by a very simple process.

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“…Atomically thin two-dimensional (2D) transition-metal dichalcogenides (TMDCs, MX 2 , where M and X represent transition-metal ions and chalcogen ions, respectively) have attracted tremendous research interest in both theoretical and technological studies due to their excellent electrical, mechanical, and chemical properties. − Among them, molybdenum disulfide (MoS 2 ) has been extensively studied in electronics, optoelectronics, and flexible and wearable devices. − Especially, its dangling-bond-free surface and atomic thickness offer transparency with moderate band gap energy, good carrier mobility, highly efficient light absorption, and integration on various substrates and materials, suitable for the realization of future nanoscale devices. , …”

Section: Introductionmentioning

confidence: 99%

Direct CVD Synthesis of MoS₂ Monolayers on Glass by Carbothermal Reduction

et al. 2023

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Chemical vapor deposition (CVD) synthesis for two-dimensional (2D) transition-metal dichalcogenides (TMDCs) is fundamentally important for realizing high-quality single crystals of TMDCs for future electronic and optoelectronic device applications. However, CVD synthesis of TMDCs generally requires a high synthetic temperature (>700 °C), which limits the choice of growth substrates and their broad applications. In this work, we present direct CVD synthesis of 2D MoS 2 on glass. The CVD growth temperature was significantly decreased to 500 °C by employing carbothermal reduction, which uses carbon as the catalyst for reducing the thermal decomposition temperature of MoO 3 precursors. MoS 2 single crystals grown on glass showed no observable degradation in electrical, optical, and structural properties compared to MoS 2 grown at high temperatures. The MoS 2 grown on glass exhibited field effect mobility around 7.6 cm 2 V −1 s −1 and a high ON/OFF ratio of up to 10 7 , photoresponsivity up to 40 A/W, and stable and repeatable photocurrent. These findings demonstrate a promising strategy in the CVD growth of 2D materials and the design of their flexible and transparent devices.

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Energy level modulation of MoS₂monolayers by halide doping for an enhanced hydrogen evolution reaction

Abstract: Engineering energy levels of MoS2 monolayers via halide atom doping can greatly contribute to the charge kinetics and the catalytic activities.

Cited by 10 publications

References 49 publications

Electronic Modulation of Semimetallic Electrode for 2D van der Waals Devices

Electronic Modulation of Semimetallic Electrode for 2D van der Waals Devices

Achieving Adsorbate-Free Monolayered MoS₂ Field Effect Transistors by Controlled Surface Gas Treatment

Direct CVD Synthesis of MoS₂ Monolayers on Glass by Carbothermal Reduction

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Energy level modulation of MoS2monolayers by halide doping for an enhanced hydrogen evolution reaction

Abstract: Engineering energy levels of MoS2 monolayers via halide atom doping can greatly contribute to the charge kinetics and the catalytic activities.

Cited by 10 publications

References 49 publications

Electronic Modulation of Semimetallic Electrode for 2D van der Waals Devices

Electronic Modulation of Semimetallic Electrode for 2D van der Waals Devices

Achieving Adsorbate-Free Monolayered MoS2 Field Effect Transistors by Controlled Surface Gas Treatment

Direct CVD Synthesis of MoS2 Monolayers on Glass by Carbothermal Reduction

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Product

Resources

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Energy level modulation of MoS₂monolayers by halide doping for an enhanced hydrogen evolution reaction

Achieving Adsorbate-Free Monolayered MoS₂ Field Effect Transistors by Controlled Surface Gas Treatment

Direct CVD Synthesis of MoS₂ Monolayers on Glass by Carbothermal Reduction