Tungsten Disulfide Nanodispersions for Inkjet Printing and Semiconducting Devices

ABSTRACTIn this work, we demonstrate optical and electrical transport properties of chemically exfoliated WS2 in cyclohexanone/ terpineol solvent using different sonication times. High electrical conductivity of WS2 nanodispersions was observed when appropriate amount of voltage was applied indicating their semi-conductive behavior. Surface morphology of WS2 nanodispersions sonicated at different times were studied using optical microscopy. Optical bandgap of WS2 nanodispersions were determined from optical absorbance spectrum. Inkjet printing was used to demonstrate uniform distribution of WS2 nanosheets and their precise and large scale printability. These dispersions indicate the potential of WS2 in various optoelectronic and semiconducting device applications.

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Pressure-Induced Structural Phase Transition and Metallization in Ga2Se3 up to 40.2 GPa under Non-Hydrostatic and Hydrostatic Environments

Crystals ◽

10.3390/cryst11070746 ◽

2021 ◽

Vol 11 (7) ◽

pp. 746

Author(s):

Meiling Hong ◽

Lidong Dai ◽

Haiying Hu ◽

Xinyu Zhang

Keyword(s):

Phase Transition ◽

Electrical Conductivity ◽

High Pressure ◽

Phase Transformation ◽

Transport Properties ◽

Electrical Transport ◽

Structural Phase ◽

Structure Evolution ◽

Systematic Research ◽

Electrical Transport Properties

A series of investigations on the structural, vibrational, and electrical transport characterizations for Ga2Se3 were conducted up to 40.2 GPa under different hydrostatic environments by virtue of Raman scattering, electrical conductivity, high-resolution transmission electron microscopy, and atomic force microscopy. Upon compression, Ga2Se3 underwent a phase transformation from the zinc-blende to NaCl-type structure at 10.6 GPa under non-hydrostatic conditions, which was manifested by the disappearance of an A mode and the noticeable discontinuities in the pressure-dependent Raman full width at half maximum (FWHMs) and electrical conductivity. Further increasing the pressure to 18.8 GPa, the semiconductor-to-metal phase transition occurred in Ga2Se3, which was evidenced by the high-pressure variable-temperature electrical conductivity measurements. However, the higher structural transition pressure point of 13.2 GPa was detected for Ga2Se3 under hydrostatic conditions, which was possibly related to the protective influence of the pressure medium. Upon decompression, the phase transformation and metallization were found to be reversible but existed in the large pressure hysteresis effect under different hydrostatic environments. Systematic research on the high-pressure structural and electrical transport properties for Ga2Se3 would be helpful to further explore the crystal structure evolution and electrical transport properties for other A2B3-type compounds.

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Structure-Electrical Transport Property Relationship of Anisotropic iPP/CNT Films

MRS Proceedings ◽

10.1557/opl.2013.445 ◽

2013 ◽

Vol 1499 ◽

Cited By ~ 1

Author(s):

Parvathalu Kalakonda ◽

Michael Daly ◽

Kaikai Xu ◽

Yaniel Cabrera ◽

Robert Judith ◽

...

Keyword(s):

Electrical Conductivity ◽

Electrical Transport ◽

Preparation Method ◽

Weight Percent ◽

Electrical Transport Properties ◽

Oriented Polymer ◽

Nano Composite ◽

Nano Structure ◽

Relationship Of ◽

Fine Tune

ABSTRACTThe internal micro/nano-structure of anisotropically oriented polymer/CNTs composites determines their macroscopic properties. However, the connections between the two are not fully understood. The varying of CNT concentration, preparation method, and a thermodynamic parameter (e.g. temperature) can all play interconnected role. In this work, the macroscopic electrical conductivity was measured perpendicular to the film thickness of an insulating polymer (isotactic PolyPropylene, iPP) and a nano-composite of iPP with 5 weight percent of CNT. The thin films studied were sheared (anisotropically nano-structured) and non-sheared (with random internal structure). In general the effect of melt shearing induces anisotropy on the electrical transport properties of the iPP/CNT films in directions parallel and perpendicular to the direction of orientation. Our results show that for the pure iPP, resistivity slightly increases with shear at higher temperatures. When CNTs are introduced, there is a large difference between the resistivity of the sheared and non-sheared nanocomposite. The sheared PNCs when the CNTs are aligned parallel to each other, have higher resistivity, which is possibly due to the higher concentration at which the percolation threshold occurs in this arrangement. The resistivity decreases overall, as the temperature increases from 0 to 50 °C. These results show that CNTs can be used to control and fine tune the desired macroscopic physical properties of nanocomposites, by concentration and orientation, such as electrical conductivity, for applications where such properties are necessary.

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Magnetic and Electrical Transport Properties of Vanadium Telluride

Zeitschrift für Naturforschung A ◽

10.1515/zna-1980-0708 ◽

1980 ◽

Vol 35 (7) ◽

pp. 701-703 ◽

Cited By ~ 2

Author(s):

C. Prasad ◽

R. A. Singh

Keyword(s):

Electrical Conductivity ◽

Dielectric Constant ◽

Magnetic Susceptibility ◽

Electrical Transport ◽

Powdered Sample ◽

Neel Temperature ◽

Electrical Transport Properties ◽

Néel Temperature ◽

Paramagnetic Curie Temperature ◽

Temperature Range

Measurements of the magnetic susceptibility of a powdered sample of VTe in the temperature range 90 - 700 K, and of the a.c. electrical conductivity (σ), thermoelectric power (θ) and dielectric constant (ε′) of pressed pellets of the compound in the temperature range 300 -1100 K are reported. The compound is found to be antiferromagnetic with Neel temperature 420 ± 5 K. The effective paramagnetic moment and paramagnetic Curie temperature are found to be 1.6 μB and - 250 K, respectively. The dependence of σ, θ and ε′ on temperature shows no anomaly at the Neel temperature and is indicative of the metallic nature of the compound.

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Computational Analysis of Strain Effects on Electrical Transport Properties of Crystalline Nanocomposite Thin Films

Volume 11: Nano and Micro Materials, Devices and Systems; Microsystems Integration ◽

10.1115/imece2011-64641 ◽

2011 ◽

Author(s):

Hua Li ◽

Gang Li

Keyword(s):

Thin Films ◽

Electrical Conductivity ◽

Band Structure ◽

Transport Properties ◽

Electrical Transport ◽

Electronic Band Structure ◽

Electrical Transport Properties ◽

Electronic Band ◽

Strain Effects ◽

Nanocomposite Thin Films

In this work, we model the strain effects on the electrical transport properties of Si/Ge nanocomposite thin films. We utilize a two-band k·p theory to calculate the variation of the electronic band structure as a function of externally applied strains. By using the modified electronic band structure, electrical conductivity of the Si/Ge nanocomposites is calculated through a self-consistent electron transport analysis, where a nonequilibrium Green’s function (NEGF) is coupled with the Poisson equation. The results show that both the tensile uniaxial and biaxial strains increase the electrical conductivity of Si/Ge nanocomposite. The effects are more evident in the biaxial strain cases.

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Imaging of local structures affecting electrical transport properties of large graphene sheets by lock-in thermography

Science Advances ◽

10.1126/sciadv.aau3407 ◽

2019 ◽

Vol 5 (2) ◽

pp. eaau3407 ◽

Cited By ~ 12

Author(s):

H. Nakajima ◽

T. Morimoto ◽

Y. Okigawa ◽

T. Yamada ◽

Y. Ikuta ◽

...

Keyword(s):

Transport Properties ◽

Electrical Transport ◽

Chemical Vapor ◽

Atomic Scale ◽

Electrical Transport Properties ◽

Large Area ◽

Graphene Layers ◽

Device Applications ◽

Chemical Vapor Deposition Graphene ◽

Lock In

The distribution of defects and dislocations in graphene layers has become a very important concern with regard to the electrical and electronic transport properties of device applications. Although several experiments have shown the influence of defects on the electrical properties of graphene, these studies were limited to measuring microscopic areas because of their long measurement times. Here, we successfully imaged various local defects in a large area of chemical vapor deposition graphene within a reasonable amount of time by using lock-in thermography (LIT). The differences in electrical resistance caused by the micrometer-scale defects, such as cracks and wrinkles, and atomic-scale domain boundaries were apparent as nonuniform Joule heating on polycrystalline and epitaxially grown graphene. The present results indicate that LIT can serve as a fast and effective method of evaluating the quality and uniformity of large graphene films for device applications.

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Thermoelectric properties of polycrystalline Bi2Se3−x by powder compaction sintering

Modern Physics Letters B ◽

10.1142/s0217984920502061 ◽

2020 ◽

Vol 34 (18) ◽

pp. 2050206

Author(s):

Ying Zhou ◽

Zhenhua Ge ◽

Jun Guo ◽

Jing Feng

Keyword(s):

Electrical Conductivity ◽

Seebeck Coefficient ◽

Carrier Concentration ◽

Thermoelectric Properties ◽

Thermoelectric Materials ◽

Electrical Transport ◽

Bulk Material ◽

Powder Compaction ◽

Electrical Transport Properties ◽

X Ray

[Formula: see text] is a [Formula: see text] compound (where Pn = Bi and Sb, Ch = Te, Se, and S), which has attracted increasing attention as a candidate for use in thermoelectric applications. Previous studies demonstrated the advantage of [Formula: see text] thermoelectric materials, despite an inferior thermoelectric performance. Herein, a series of [Formula: see text] ([Formula: see text], 0.10, 0.15, 0.20, and 0.25) thermoelectric materials were prepared by powder compaction sintering. The effects of phase structures and microstructure of the [Formula: see text] bulk material were analyzed by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The thermoelectric properties, including Seebeck coefficient, electrical conductivity, and thermal conductivity, were measured systematically. The results show that carrier concentration increased with decreasing Se content, which in turn affected the electrical transport properties. Low Se contents gave larger power factor (PF) values than the pristine [Formula: see text] sample, the maximum PF value being [Formula: see text] at 320 K for [Formula: see text]. The variation in PF was attributed to the variations in electrical conductivity [Formula: see text] and Seebeck coefficient [Formula: see text] upon optimizing Se content. The [Formula: see text] samples showed an enhanced thermoelectric figure of merit (ZT) with increasing measurement temperature, due to the increased [Formula: see text] value, [Formula: see text], and decreased [Formula: see text]. The [Formula: see text] sample exhibited the highest ZT (0.28) at 575 K, while [Formula: see text] exhibited the lowest ZT (0.14) at 325 K. This indicated that tuning Se content was an effective way to enhance carrier concentration.

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