Fabrication and electrical performance of CVD-grown MoS2 transistor

Thin films of MoS2 bilayer nanoflakes, which are predominantly a single flake thick and with flakes in edge-to-edge contact, have been produced via self-assembled tiling at the planar interface between two immiscible liquids. Films of several square centimeters extent can be produced with a total covered area approaching 90% and over 70% of the film covered by single flakes without overlap. Films produced through liquid/liquid assembly are shown to produce a lower uncovered area fraction and more uniform thickness when compared with films of similar areal coverage produced by the “top-down” techniques of spin coating and spray coating. Statistical analysis of flake coverage data, measured by atomic force microscopy (AFM), shows that liquid/liquid assembly produces a distinctly different variation in film thickness than conventional top-down deposition. This supports the hypothesis that the two-dimensional (2D) confinement of liquid/liquid assembly produces more uniform films. Demonstrator field-effect transistors (FETs) manufactured from the films exhibit mobility and on/off current ratios of 0.73 cm2 V–1 s–1 and 105, respectively, comparable to FETs of similar layout and chemical vapor deposition (CVD)-grown or mechanically cleaved single-crystal MoS2 channel material. This work demonstrates the use of liquid/liquid interfaces as a useful tool for the self-assembly of high-performance thin-film devices made from dispersions of 2D materials.

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“…Data source indicated adjacent to each plotted point. Full data is in the Supporting Information, Table S1. ,,,− …”

Section: Resultsmentioning

confidence: 99%

Tiled Monolayer Films of 2D Molybdenum Disulfide Nanoflakes Assembled at Liquid/Liquid Interfaces

Neilson

Avery

Derby

2020

ACS Appl. Mater. Interfaces

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“…In recent studies, the carrier mobility of TMDC is severely suppressed due to the low optical phonon energy [15,16]. Conventionally, CVD-grown monolayer MoS 2 FETs on Si/SiO 2 substrate showed the carrier mobility in the ranges of 0.1-10 cm 2 V −1 s −1 in previous studies [17][18][19][20]. Therefore, in order to increase the carrier mobility, the engineering of gate dielectric has been demonstrated [21][22][23].…”

Section: Introductionmentioning

confidence: 99%

Reduced interfacial fluctuation leading enhanced mobility in a monolayer MoS₂ DG FET under low vertical electric field

Sakong

et al. 2019

Nanotechnology

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Compared to the silicon device whose performance is severely degraded due to the pin-holes and channel inactive space when the channel thickness is less than 1 nm, despite monolayer transitionmetal dichalcogenides being the most stable structure to be used as a two-dimensional semiconductor material, precise analysis of the double-gate (DG) field-effect transistor (FET) device structure has hardly been performed thus far. Hence, we analyzed the device operation characteristics of single-gate and DG sweeps in a monolayer MoS 2 DG FET structure, where the interfacial carrier behavior is distinguished from both gates by the different gate dielectric materials at the top and bottom. The synchronized DG sweep operation with biasing of V TG and V BG (=10 V TG ) increased the carrier mobility by a factor of 4.85 compared with the independent DG sweep. Direct-current analysis and low-frequency noise modeling indicate that the device performance improves under equivalent gate voltages from both sides, because the device operates in a low vertical electric field and the interfacial carrier fluctuation effect is significantly reduced.

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“…The interest originates from its high surface-to-volume ratio comparable to the surfaceto-volume ratio of graphene, indirect-to-direct band-gap, and layer-dependent tunable band-gap. The MoS 2 exhibits its enormous potential applications in the field of transistor, [7] field-effect transistor (FET), [8] photocatalytic degradation, [9] hydrogen production, [10] gas sensor, [11] solar cells, [12] and photodetector. [13] The electronic properties of MoS 2 strongly depend on the layer thickness.…”

Section: Introductionmentioning

confidence: 99%

First-principles study of magnetism of 3d transition metals and nitrogen co-doped monolayer MoS₂*

Lin

Guo

et al. 2020

Chinese Phys. B

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The electronic structures and magnetic properties of diverse transition metal (TM = Fe, Co, and Ni) and nitrogen (N) co-doped monolayer MoS2 are investigated by using density functional theory. The results show that the intrinsic MoS2 does not have magnetism initially, but doped with TM (TM = Fe, Co, and Ni) the MoS2 possesses an obvious magnetism distinctly. The magnetic moment mainly comes from unpaired Mo:4d orbitals and the d orbitals of the dopants, as well as the S:3p states. However, the doping system exhibits certain half-metallic properties, so we select N atoms in the V family as a dopant to adjust its half-metal characteristics. The results show that the (Fe, N) co-doped MoS2 can be a satisfactory material for applications in spintronic devices. On this basis, the most stable geometry of the (2Fe–N) co-doped MoS2 system is determined by considering the different configurations of the positions of the two Fe atoms. It is found that the ferromagnetic mechanism of the (2Fe–N) co-doped MoS2 system is caused by the bond spin polarization mechanism of the Fe–Mo–Fe coupling chain. Our results verify that the (Fe, N) co-doped single-layer MoS2 has the conditions required to become a dilute magnetic semiconductor.

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Fabrication and electrical performance of CVD-grown MoS2 transistor

Cited by 3 publications

References 10 publications

Tiled Monolayer Films of 2D Molybdenum Disulfide Nanoflakes Assembled at Liquid/Liquid Interfaces

Tiled Monolayer Films of 2D Molybdenum Disulfide Nanoflakes Assembled at Liquid/Liquid Interfaces

Reduced interfacial fluctuation leading enhanced mobility in a monolayer MoS₂ DG FET under low vertical electric field

First-principles study of magnetism of 3d transition metals and nitrogen co-doped monolayer MoS₂*

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Fabrication and electrical performance of CVD-grown MoS2 transistor

Cited by 3 publications

References 10 publications

Tiled Monolayer Films of 2D Molybdenum Disulfide Nanoflakes Assembled at Liquid/Liquid Interfaces

Tiled Monolayer Films of 2D Molybdenum Disulfide Nanoflakes Assembled at Liquid/Liquid Interfaces

Reduced interfacial fluctuation leading enhanced mobility in a monolayer MoS2 DG FET under low vertical electric field

First-principles study of magnetism of 3d transition metals and nitrogen co-doped monolayer MoS2*

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Reduced interfacial fluctuation leading enhanced mobility in a monolayer MoS₂ DG FET under low vertical electric field

First-principles study of magnetism of 3d transition metals and nitrogen co-doped monolayer MoS₂*