Anisotropic optical characteristics of Au-doped rhenium diselenide single crystals

Dumcenco, Dumitru; Huang, Wei‐Yuan; Huang, Y. S.; Tiong, K. K.

doi:10.1016/j.jallcom.2008.09.174

Cited by 7 publications

(5 citation statements)

References 14 publications

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“…We now consider whether the pronounced angle-dependence of the Raman spectra can be used to determine the orientation of a given flake. Clearly, the morphology of cleaved flakes already gives a strong clue, since cleavage edges often lie along the in-plane a and b axes, − though it is not always possible to distinguish between a and b axes visually, and indeed, micromechanical exfoliation frequently yields very irregular shapes where such edges cannot even be identified. For layers grown by any kind of vapor deposition, morphological information will not be available, and an important task will be to map out the domain structure in the film.…”

Section: Resultsmentioning

confidence: 99%

Raman Spectra of Monolayer, Few-Layer, and Bulk ReSe₂: An Anisotropic Layered Semiconductor

et al. 2014

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Rhenium diselenide (ReSe2) is a layered indirect gap semiconductor for which micromechanical cleavage can produce monolayers consisting of a plane of rhenium atoms with selenium atoms above and below. ReSe2 is unusual among the transition-metal dichalcogenides in having a low symmetry; it is triclinic, with four formula units per unit cell, and has the bulk space group P1̅. Experimental studies of Raman scattering in monolayer, few-layer, and bulk ReSe2 show a rich spectrum consisting of up to 16 of the 18 expected lines with good signal strength, pronounced in-plane anisotropy of the intensities, and no evidence of degradation of the sample during typical measurements. No changes in the frequencies of the Raman bands with layer thickness down to one monolayer are observed, but significant changes in relative intensity of the bands allow the determination of crystal orientation and of monolayer regions. Supporting theory includes calculations of the electronic band structure and Brillouin zone center phonon modes of bulk and monolayer ReSe2 as well as the Raman tensors determining the scattering intensity of each mode. It is found that, as for other transition-metal dichalcogenides, Raman scattering provides a powerful diagnostic tool for studying layer thickness and also layer orientation in few-layer ReSe2.

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Section: Resultsmentioning

confidence: 99%

Raman Spectra of Monolayer, Few-Layer, and Bulk ReSe₂: An Anisotropic Layered Semiconductor

et al. 2014

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“…Rhenium diselenide (ReSe 2 ) is a member of the layered transition metal dichalcogenides (TMDs), which has attracted a lot of attention due to the extremely anisotropic electrical, optical and mechanical properties stemming from the strong in-plane anisotropy consequence of its reduced crystal symmetry [ 1 , 2 , 3 , 4 ]. Contrary to other hexagonal TMDs, the room temperature thermodynamically stable 1T phase for ReSe 2 has a distorted triclinic symmetry, which endows the material with anisotropic responses in many properties [ 5 , 6 , 7 ].…”

Section: Introductionmentioning

confidence: 99%

Electric Transport in Few-Layer ReSe2 Transistors Modulated by Air Pressure and Light

et al. 2022

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We report the fabrication and optoelectronic characterization of field-effect transistors (FETs) based on few-layer ReSe2. The devices show n-type conduction due to the Cr contacts that form low Schottky barriers with the ReSe2 nanosheet. We show that the optoelectronic performance of these FETs is strongly affected by air pressure, and it undergoes a dramatic increase in conductivity when the pressure is lowered below the atmospheric one. Surface-adsorbed oxygen and water molecules are very effective in doping ReSe2; hence, FETs based on this two-dimensional (2D) semiconductor can be used as an effective air pressure gauge. Finally, we report negative photoconductivity in the ReSe2 channel that we attribute to a back-gate-dependent trapping of the photo-excited charges.

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“…ReSe 2 crystals with triclinic symmetry are optically biaxial with a clustering of "diamond chains" composed of Re ions forming along the baxis. 17,20 However other hexagonal LTMDs (such as 2H-MoS 2 and MoSe 2 ) are optically uniaxial and the optical axis in these LTMDs is perpendicular to the van der Waals plane. 20 The structural distortion of 1T-ReSe 2 makes it exhibit anisotropic responses in many properties, with the expectation of linearly polarized light perpendicular to the basal plane.…”

Section: Introductionmentioning

confidence: 99%

“…17,20 However other hexagonal LTMDs (such as 2H-MoS 2 and MoSe 2 ) are optically uniaxial and the optical axis in these LTMDs is perpendicular to the van der Waals plane. 20 The structural distortion of 1T-ReSe 2 makes it exhibit anisotropic responses in many properties, with the expectation of linearly polarized light perpendicular to the basal plane. 19 DFT calculations nd that the binding energy of bilayer ReSe 2 is 0.109 eV per molecule, similar to that of bilayer MoS 2 (0.112 eV per molecule), but lower than that of four-layer ReSe 2 (0.165 eV per molecule), indicating the existence of relatively long-range interlayer interactions.…”

Section: Introductionmentioning

confidence: 99%

Layer-dependent electrical and optoelectronic responses of ReSe2 nanosheet transistors

et al. 2014

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The ability to control the appropriate layer thickness of transition metal dichalcogenides (TMDs) affords the opportunity to engineer many properties for a variety of applications in possible technological fields. Here we demonstrate that band-gap and mobility of ReSe2 nanosheet, a new member of the TMDs, increase when the layer number decreases, thus influencing the performances of ReSe2 transistors with different layers. A single-layer ReSe2 transistor shows much higher device mobility of 9.78 cm(2) V(-1) s(-1) than few-layer transistors (0.10 cm(2) V(-1) s(-1)). Moreover, a single-layer device shows high sensitivity to red light (633 nm) and has a light-improved mobility of 14.1 cm(2) V(-1) s(-1). Molecular physisorption is used as "gating" to modulate the carrier density of our single-layer transistors, resulting in a high photoresponsivity (Rλ) of 95 A W(-1) and external quantum efficiency (EQE) of 18 645% in O2 environment. This work highlights the fact that the properties of ReSe2 can be tuned in terms of the number of layers and gas molecule gating, and single-layer ReSe2 with appropriate band-gap is a promising material for future functional device applications.

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Anisotropic optical characteristics of Au-doped rhenium diselenide single crystals

Cited by 7 publications

References 14 publications

Raman Spectra of Monolayer, Few-Layer, and Bulk ReSe₂: An Anisotropic Layered Semiconductor

Raman Spectra of Monolayer, Few-Layer, and Bulk ReSe₂: An Anisotropic Layered Semiconductor

Electric Transport in Few-Layer ReSe2 Transistors Modulated by Air Pressure and Light

Layer-dependent electrical and optoelectronic responses of ReSe2 nanosheet transistors

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Anisotropic optical characteristics of Au-doped rhenium diselenide single crystals

Cited by 7 publications

References 14 publications

Raman Spectra of Monolayer, Few-Layer, and Bulk ReSe2: An Anisotropic Layered Semiconductor

Raman Spectra of Monolayer, Few-Layer, and Bulk ReSe2: An Anisotropic Layered Semiconductor

Electric Transport in Few-Layer ReSe2 Transistors Modulated by Air Pressure and Light

Layer-dependent electrical and optoelectronic responses of ReSe2 nanosheet transistors

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Product

Resources

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Raman Spectra of Monolayer, Few-Layer, and Bulk ReSe₂: An Anisotropic Layered Semiconductor

Raman Spectra of Monolayer, Few-Layer, and Bulk ReSe₂: An Anisotropic Layered Semiconductor