Transmission spectra of some transition metal dichalcogenides. II. Group VIA: trigonal prismatic coordination

Beal, A R; Knights, J. C.; Liang, W. Y.

doi:10.1088/0022-3719/5/24/016

Cited by 295 publications

(282 citation statements)

References 13 publications

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“…The two broad features marked with asterisks at 610 and 660 nm were assigned to characteristic A and B exciton peaks of 2H-MoS 2 , respectively. [82] Using a Tauc plot we obtained an indirect band gap of 1.2 eV for a 2000 cycle film on borosilicate glass (Figure 7b), in agreement with the generally accepted value of 1.3 eV for bulk MoS 2 .…”

Section: Optical Properties On Glass Substratessupporting

confidence: 86%

Atomic Layer Deposition of Crystalline MoS₂ Thin Films: New Molybdenum Precursor for Low‐Temperature Film Growth

Mattinen

Hatanpää

Sarnet

et al. 2017

Adv Materials Inter

106

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Compared to the most well-known 2D material, graphene, which is a semi-metal, the semiconducting 2H phase of MoS 2 is advantageous in having a band gap suitable for electronic applications. In bulk form, MoS 2 has an indirect band gap of 1.3 eV, which increases as a function of decreasing film thickness. In monolayer MoS 2 (thickness ≈0.6 nm), the band gap becomes direct with a width of 1.8 eV. [1] Importantly, to meet the requirements of different applications, properties of MoS 2 and other TMDCs can be tuned by controlling the thickness, [1] doping and alloying, [5][6][7][8] surface modification and functionalization, [9][10][11] strain, [12,13] and by creating heterostructures with other 2D materials. [6,[14][15][16] The appealing properties of TMDCs have led to a wide range of proposed applications. MoS 2 has been extensively studied as a channel material in conventional field-effect transistors, [17][18][19][20][21] as well as phototransistors and other optoelectronic devices. [16,21,22] The 2D structure of TMDCs plays a crucial role in possible applications relying on more exotic quantum phenomena, such as valleytronics. [23,24] MoS 2 has also shown promise in, for example, catalysis, [25] batteries, [26] photovoltaics, [27] sensors, [28] and medicine. [29] The production of high-quality, large-area MoS 2 films with a thickness controllable down to a monolayer, as required in many of the aforementioned applications, still remains a major challenge. Additionally, in many cases, the processing temperature should be kept as low as possible in order to avoid damaging sensitive substrates, such as polymers or nanostructures. Initially, flakes of monolayer MoS 2 were produced from natural MoS 2 crystals using micromechanical exfoliation, a topdown method capable of producing high-quality monolayers, albeit with poor throughput as well as limited control over flake thickness and dimensions. [4,30,31] Liquid-phase exfoliation of bulk crystals, on the other hand, offers good scalability, but often suffers from limited flake size, poor crystallinity, or contamination. [4,31,32] Bottom-up methods offer a more controllable way to produce MoS 2 films. High-quality MoS 2 thin films are most commonly deposited by chemical vapor deposition (CVD) or sulfurization of metal or metal oxide thin films. The most common Molybdenum disulfide (MoS 2 ) is a semiconducting 2D material, which has evoked wide interest due to its unique properties. However, the lack of controlled and scalable methods for the production of MoS 2 films at low temperatures remains a major hindrance on its way to applications. In this work, atomic layer deposition (ALD) is used to deposit crystalline MoS 2 thin films at a relatively low temperature of 300 °C. A new molybdenum precursor, Mo(thd) 3 (thd = 2,2,6,6-tetramethylheptane-3,5-dionato), is synthesized, characterized, and used for film deposition with H 2 S as the sulfur precursor. Self-limiting growth with a low growth rate of ≈0.025 Å cycle −1 , straightforward thickness control, and large-area uni...

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Section: Optical Properties On Glass Substratessupporting

confidence: 86%

Atomic Layer Deposition of Crystalline MoS₂ Thin Films: New Molybdenum Precursor for Low‐Temperature Film Growth

Mattinen

Hatanpää

Sarnet

et al. 2017

Adv Materials Inter

106

View full text Add to dashboard Cite

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“…The corresponding absorption peaks can be identified as shown in Figure 5b. Both of them correspond to A and B exciton transitions in the direct band-gap structure [14,18,59]. A clear indirect to direct band structure transition between bilayer and monolayer MoS2 can be best seen from the photocurrent spectra shown in Figure 5c.…”

Section: Electronic Band Structure: Optical and Optoelectronic Propermentioning

confidence: 82%

Recent Advancement on the Optical Properties of Two-Dimensional Molybdenum Disulfide (MoS2) Thin Films

et al. 2015

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Abstract:The emergence of two-dimensional (2D) materials has led to tremendous interest in the study of graphene and a series of mono-and few-layered transition metal dichalcogenides (TMDCs). Among these TMDCs, the study of molybdenum disulfide (MoS2) has gained increasing attention due to its promising optical, electronic, and optoelectronic properties. Of particular interest is the indirect to direct band-gap transition from bulk and few-layered structures to mono-layered MoS2, respectively. In this review, the study of these properties is summarized. The use of Raman and Photoluminescence (PL) spectroscopy of MoS2 has become a reliable technique for differentiating the number of molecular layers in 2D MoS2.

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“…2H and 3R MoS 2 both correspond to trigonal prismatic coordination. 72,73 The 2H type, which is dominant and more stable in nature, has two layers per unit cell stacked in the hexagonal symmetry. The 3R-type has three layers per cell in rhombohedral symmetry, and is unstable and easily transforms to 2H upon heating.…”

Section: Crystal Propertiesmentioning

confidence: 99%

Two-dimensional layered MoS₂: rational design, properties and electrochemical applications

Zhang

Liu

et al. 2016

Energy Environ. Sci.

542

328

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The layered molybdenum chalcogenide MoS 2 has attracted wide attention due to its potential electrochemical applications. Based on its unique physical and chemical properties, numerous advances have shown that nanostructured MoS 2 , with the advantages of low cost and outstanding properties, is a promising candidate for environmentally benign energy conversion and storage (ECS) devices.Nowadays, in order to lessen the reliance on fossil fuels, the production of hydrogen from water splitting has become an important issue. Hence, developing catalysts composed of earth-abundant elements that possess activities comparable to those of noble metals is of great urgency. According to DFT calculations in terms of HER free-energy diagrams, MoS 2 could be used as an effective substitute for noble metals. Meanwhile, MoS 2 with various structures has also been applied in the field of energy storage, including batteries and supercapacitors. Additionally, due to their layer-dependent electrical properties, MoS 2 -based electrochemical devices have been applied as sensors for a variety of chemicals.In this review, we summarize recent advances in the development of MoS 2 with high-performance in various electrochemical domains, and recent progress in discovering the mechanisms underlying the enhanced activity. Moreover, we summarize the critical obstacles facing MoS 2 , and discuss strategies for further improving its activity. Lastly, we offer some suggestions on the pathways toward achieving high performance competitive with noble metal counterparts, and perspectives on practical applications of MoS 2 in the future. Broader contextThe development of inexhaustible and clean energy technologies has far-reaching benefits for our society. Owing to its high anisotropy and unique crystal structure, the attractive properties of 2D molybdenum disulfide (MoS 2 ) can be utilized in a variety of energy conversion and storage (ECS) applications. Therefore, understanding how these properties can be tuned and the tunable properties can be utilized becomes increasingly important. In this review, we first summarize recent synthetic strategies toward preparation of MoS 2 with different structures, and its role in several important renewable energy technologies. We then discuss the relationship between the tuned properties and the performance of MoS 2 in different applications, emerging trends during their development, and challenges facing them, offering our perspectives on how to effectively advance the development of MoS 2 -based devices.

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Transmission spectra of some transition metal dichalcogenides. II. Group VIA: trigonal prismatic coordination

Cited by 295 publications

References 13 publications

Atomic Layer Deposition of Crystalline MoS₂ Thin Films: New Molybdenum Precursor for Low‐Temperature Film Growth

Atomic Layer Deposition of Crystalline MoS₂ Thin Films: New Molybdenum Precursor for Low‐Temperature Film Growth

Recent Advancement on the Optical Properties of Two-Dimensional Molybdenum Disulfide (MoS2) Thin Films

Two-dimensional layered MoS₂: rational design, properties and electrochemical applications

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Transmission spectra of some transition metal dichalcogenides. II. Group VIA: trigonal prismatic coordination

Cited by 295 publications

References 13 publications

Atomic Layer Deposition of Crystalline MoS2 Thin Films: New Molybdenum Precursor for Low‐Temperature Film Growth

Atomic Layer Deposition of Crystalline MoS2 Thin Films: New Molybdenum Precursor for Low‐Temperature Film Growth

Recent Advancement on the Optical Properties of Two-Dimensional Molybdenum Disulfide (MoS2) Thin Films

Two-dimensional layered MoS2: rational design, properties and electrochemical applications

Contact Info

Product

Resources

About

Atomic Layer Deposition of Crystalline MoS₂ Thin Films: New Molybdenum Precursor for Low‐Temperature Film Growth

Atomic Layer Deposition of Crystalline MoS₂ Thin Films: New Molybdenum Precursor for Low‐Temperature Film Growth

Two-dimensional layered MoS₂: rational design, properties and electrochemical applications