Evaluation of Sputtering Deposited 2-Dimensional MoS2 Film by Raman Spectroscopy

ABSTRACTMolybdenum disulfide (MoS2), one of the transition-metal dichalcogenides, is a 2-dimensional semiconducting material that has a layered structure. Owing to excellent optical and electronic properties, the ultra-thin MoS2 film is expected to be used for various devices, such as transistors and flexible displays. In this study, we investigated the physical and chemical properties of sputtered-MoS2 film in the sub-10-nm region by Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). As the results of Raman spectroscopy investigations, we observed two Raman modes, E12g and A1g, in the 2-dimensional MoS2 films. As the thickness of the MoS2 film decreased, the peak frequency difference between E12g and A1g modes increased. From the XPS investigations, we confirmed sulfur reductions from the 2-dimensional MoS2 films. Therefore, we considered that the sulfur vacancies in the MoS2 film affected the Raman peak positions. Moreover, we performed the additional sulfurization of sputtered-MoS2 films. From the XPS and Raman investigations, the quality of the sputtered-MoS2 films was improved by the additional sulfurization.

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An emerging Janus MoSeTe material for potential applications in optoelectronic devices

Journal of Materials Chemistry C ◽

10.1039/c9tc03936h ◽

2019 ◽

Vol 7 (39) ◽

pp. 12312-12320 ◽

Cited By ~ 14

Author(s):

Xiaoyong Yang ◽

Deobrat Singh ◽

Zhitong Xu ◽

Ziwei Wang ◽

Rajeev Ahuja

Keyword(s):

First Principles ◽

Transition Metal Dichalcogenides ◽

Chemical Properties ◽

Detailed Comparison ◽

Physical And Chemical Properties ◽

First Principles Calculations ◽

Potential Applications ◽

Metal Dichalcogenides ◽

Physical And Chemical ◽

And Chemical Properties

Motivated by the extraordinary physical and chemical properties of Janus transition-metal dichalcogenides (TMDs) due to the change of the crystal field originating from their asymmetry structures, the electronic and optical properties of the MoSeTe monolayer in 2H and 1T phases are systematically studied by first-principles calculations, and a detailed comparison with the parental MoSe2 and MoTe2 monolayer is made.

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Gate-tunable trion binding energy in monolayer MoS2 with plasmonic superlattice

Nanoscale ◽

10.1039/d0nr02104k ◽

2020 ◽

Vol 12 (34) ◽

pp. 17754-17761

Author(s):

Zhuang Luo ◽

Hao Jia ◽

Liu Lv ◽

Quan Wang ◽

Xiaohong Yan

Keyword(s):

Transition Metal Dichalcogenides ◽

Optoelectronic Devices ◽

Chemical Properties ◽

Physical And Chemical Properties ◽

Two Dimensional ◽

Monolayer Mos2 ◽

The World ◽

Metal Dichalcogenides ◽

Physical And Chemical ◽

And Chemical Properties

Two-dimensional transition metal dichalcogenides exhibit promising potential and attract the attention of the world in the application of optoelectronic devices owing to their distinctive physical and chemical properties.

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Recent Advances in Electrical Doping of 2D Semiconductor Materials: Methods, Analyses, and Applications

Nanomaterials ◽

10.3390/nano11040832 ◽

2021 ◽

Vol 11 (4) ◽

pp. 832

Author(s):

Hocheon Yoo ◽

Keun Heo ◽

Md. Hasan Raza Ansari ◽

Seongjae Cho

Keyword(s):

Electrical Properties ◽

Transition Metal Dichalcogenides ◽

Visible Region ◽

Chemical Properties ◽

Electrical Characterization ◽

Semiconductor Materials ◽

Two Dimensional ◽

Potential Applications ◽

Metal Dichalcogenides ◽

Physical And Chemical

Two-dimensional materials have garnered interest from the perspectives of physics, materials, and applied electronics owing to their outstanding physical and chemical properties. Advances in exfoliation and synthesis technologies have enabled preparation and electrical characterization of various atomically thin films of semiconductor transition metal dichalcogenides (TMDs). Their two-dimensional structures and electromagnetic spectra coupled to bandgaps in the visible region indicate their suitability for digital electronics and optoelectronics. To further expand the potential applications of these two-dimensional semiconductor materials, technologies capable of precisely controlling the electrical properties of the material are essential. Doping has been traditionally used to effectively change the electrical and electronic properties of materials through relatively simple processes. To change the electrical properties, substances that can donate or remove electrons are added. Doping of atomically thin two-dimensional semiconductor materials is similar to that used for silicon but has a slightly different mechanism. Three main methods with different characteristics and slightly different principles are generally used. This review presents an overview of various advanced doping techniques based on the substitutional, chemical, and charge transfer molecular doping strategies of graphene and TMDs, which are the representative 2D semiconductor materials.

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Recent Progress of Two-Dimensional Materials for Ultrafast Photonics

Nanomaterials ◽

10.3390/nano11071778 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1778

Author(s):

Aojie Zhang ◽

Zihao Wang ◽

Hao Ouyang ◽

Wenhao Lyu ◽

Jingxuan Sun ◽

...

Keyword(s):

Ultrafast Lasers ◽

2D Materials ◽

Transition Metal Dichalcogenides ◽

Chemical Properties ◽

Two Dimensional ◽

Saturable Absorbers ◽

Output Performance ◽

Metal Dichalcogenides ◽

Ultrafast Photonics ◽

Physical And Chemical

Owing to their extraordinary physical and chemical properties, two-dimensional (2D) materials have aroused extensive attention and have been widely used in photonic and optoelectronic devices, catalytic reactions, and biomedicine. In particular, 2D materials possess a unique bandgap structure and nonlinear optical properties, which can be used as saturable absorbers in ultrafast lasers. Here, we mainly review the top-down and bottom-up methods for preparing 2D materials, such as graphene, topological insulators, transition metal dichalcogenides, black phosphorus, and MXenes. Then, we focus on the ultrafast applications of 2D materials at the typical operating wavelengths of 1, 1.5, 2, and 3 μm. The key parameters and output performance of ultrafast pulsed lasers based on 2D materials are discussed. Furthermore, an outlook regarding the fabrication methods and the development of 2D materials in ultrafast photonics is also presented.

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In-plane and vertical heterostructures from 1T’/2H transition-metal dichalcogenides

Oxford Open Materials Science ◽

10.1093/oxfmat/itab016 ◽

2022 ◽

Author(s):

Yang Ma ◽

Shiyu Xu ◽

Juntian Wei ◽

Bin Zhou ◽

Yongji Gong

Keyword(s):

Transition Metal ◽

Transition Metal Dichalcogenides ◽

Chemical Properties ◽

Chemical Vapor ◽

Deposition Process ◽

Flexible Devices ◽

Potential Applications ◽

Metal Dichalcogenides ◽

Z Contrast ◽

Physical And Chemical

Abstract Objectives An avalanche of research has been carried out on two-dimensional (2D) transition metal dichalcogenides (TMDs) due to their potential applications in advanced electronics and flexible devices. To take full use of the emerging 2D TMDs materials, their in-plane/vertical heterostructures have been explored, enabling effective tuning of their physical and chemical properties. However, structural differences between the various phases impede the formation of functional heterostructures. Therefore, robust synthesis strategies for heterostructures with different phases have been explored in this study. Methods A chemical vapor deposition process has been proposed in which the key parameters like reaction sources, deposition sites, etc. have been carefully adjusted, trying to achieve simultaneous synthesis of 1T’/2H in-plane and vertical heterostructures. Results Consequently, 2D in-plane RexMo1-xS2/MoS2 and vertical ReS2/MoS2 heterostructures have been produced in different regions at the same time. Atomic-resolution Z-contrast images reveal the detailed atomic structure of the 1T’/2H interfaces. The lateral interface is found to contain Mo atoms with only 5-fold coordination with S due to the phase mismatch. Conclusion This work demonstrates a route to exploit heterostructures of different phases and opens the possibility to build more complicated 2D heterostructures using CVD.

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MoS2-DNA and MoS2 based sensors

RSC Advances ◽

10.1039/c7ra02649h ◽

2017 ◽

Vol 7 (38) ◽

pp. 23573-23582 ◽

Cited By ~ 20

Author(s):

Lirong Yan ◽

Haixia Shi ◽

Xiaowei Sui ◽

Zebin Deng ◽

Li Gao

Keyword(s):

Transition Metal ◽

Family Member ◽

Transition Metal Dichalcogenides ◽

Chemical Properties ◽

Physical And Chemical Properties ◽

Metal Dichalcogenides ◽

Physical And Chemical ◽

And Chemical Properties

MoS2, a family member of transition-metal dichalcogenides, has shown highly attractive superiority for detection arising from its unique physical and chemical properties.

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Predicting two-dimensional topological phases in Janus materials by substitutional doping in transition metal dichalcogenide monolayers

npj 2D Materials and Applications ◽

10.1038/s41699-019-0118-2 ◽

2019 ◽

Vol 3 (1) ◽

Cited By ~ 10

Author(s):

Aniceto B. Maghirang ◽

Zhi-Quan Huang ◽

Rovi Angelo B. Villaos ◽

Chia-Hsiu Hsu ◽

Liang-Ying Feng ◽

...

Keyword(s):

Transition Metal ◽

2D Materials ◽

Transition Metal Dichalcogenides ◽

Chemical Properties ◽

Industrial Applications ◽

Transition Metal Dichalcogenide ◽

Two Dimensional ◽

Substitutional Doping ◽

Metal Dichalcogenides ◽

Physical And Chemical

Abstract Ultrathin Janus two-dimensional (2D) materials are attracting intense interest currently. Substitutional doping of 2D transition metal dichalcogenides (TMDs) is of importance for tuning and possible enhancement of their electronic, physical and chemical properties toward industrial applications. Using systematic first-principles computations, we propose a class of Janus 2D materials based on the monolayers MX2 (M = V, Nb, Ta, Tc, or Re; X = S, Se, or Te) with halogen (F, Cl, Br, or I) or pnictogen (N, P, As, Sb, or Bi) substitution. Nontrivial phases are obtained on pnictogen substitution of group VB (V, Nb, or Ta), whereas for group VIIB (Tc or Re), the nontrivial phases are obtained for halogen substitution. Orbital analysis shows that the nontrivial phase is driven by the splitting of M-dyz and M-dxz orbitals. Our study demonstrates that the Janus 2D materials have the tunability and suitability for synthesis under various conditions.

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Molecular chemistry approaches for tuning the properties of two-dimensional transition metal dichalcogenides

Chemical Society Reviews ◽

10.1039/c8cs00169c ◽

2018 ◽

Vol 47 (17) ◽

pp. 6845-6888 ◽

Cited By ~ 68

Author(s):

Simone Bertolazzi ◽

Marco Gobbi ◽

Yuda Zhao ◽

Claudia Backes ◽

Paolo Samorì

Keyword(s):

Transition Metal ◽

Transition Metal Dichalcogenides ◽

Chemical Properties ◽

Two Dimensional ◽

Multifunctional Materials ◽

Molecular Chemistry ◽

Physico Chemical ◽

Metal Dichalcogenides

A variety of molecular chemistry approaches are currently investigated for tailoring the physico-chemical properties of ultrathin transition metal dichalcogenides towards novel hybrid multifunctional materials and devices.

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A rapid microwave synthesis of green-emissive carbon dots with solid-state fluorescence and pH-sensitive properties

Royal Society Open Science ◽

10.1098/rsos.180245 ◽

2018 ◽

Vol 5 (7) ◽

pp. 180245 ◽

Cited By ~ 16

Author(s):

Tingting Yu ◽

Haijiao Wang ◽

Chongzheng Guo ◽

Yanli Zhai ◽

Jianzhou Yang ◽

...

Keyword(s):

Solid State ◽

Photoelectron Spectroscopy ◽

Phthalic Acid ◽

Chemical Properties ◽

Carbon Quantum Dots ◽

Feed Ratio ◽

Quantum Yields ◽

Ph Sensing ◽

Wavelength Emission ◽

Physical And Chemical

The emerging carbon quantum dots (CQDs) have been attracting significant attention for their prominent fluorescence, excellent stability and outstanding biocompatibility. Here, we report a facile one-step synthesis of highly fluorescent CQDs by using phthalic acid and triethylenediamine hexahydrate as precursors through a simple microwave-assisted method. The reaction time needed is only 60 s, which is less time-consuming than most previous reports. The phthalic acid with a benzene ring can improve the photoluminescence properties of CQDs as it can provide foreign sp 2 conjugating units, and then finally result in long-wavelength emission. The synthesized CQDs were fully characterized by transmission electron microscopy, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Besides, the impacts of different freed ratio on physical and chemical properties of CQDs were investigated in detail. The prepared CQDs exhibited strong green fluorescence with a broad maximum emission wavelength. The quantum yields of the CQDs can reach 16.1% in aqueous solution and they were successfully used in cell imaging with good biocompatibility. Moreover, in solid state, the CQDs with the feed ratio of 1 : 0.5 showed a strong green–yellow fluorescence which may have great potential to fabricate optoelectronic devices. Furthermore, the prepared CQDs also showed high pH sensitivity and can act as a fluorescence nanosensor for pH sensing.

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