Anisotropic Spectroscopy and Electrical Properties of 2D ReS_2(1–x)Se_2x Alloys with Distorted 1T Structure

Abstract

2D black phosphorus (BP) and rhenium dichalcogenides (ReX , X = S, Se) possess intrinsic in-plane anisotropic physical properties arising from their low crystal lattice symmetry, which has inspired their novel applications in electronics, photonics, and optoelectronics. Different from BP with poor environmental stability, ReX has low-symmetry distorted 1T structures with excellent stability. In ReX , the electronic structure is weakly dependent on layer numbers, which restricts their property tunability and device applications. Here, the properties are tuned, such as optical bandgap, Raman anisotropy, and electrical transport, by alloying 2D ReS and ReSe . Photoluminescence emission energy of ReS Se monolayers (x from 0 to 1 with a step of 0.1) can be continuously tuned ranging from 1.62 to 1.31 eV. Polarization behavior of Raman modes, such as ReS -like peak at 212 cm , shifts as the composition changes. Anisotropic electrical property is maintained in ReS Se with high electron mobility along b-axis for all compositions of ReS Se .

Identifying light impurities in transition metal dichalcogenides: the local vibrational modes of S and O in ReSe2 and MoSe2

“…43 It is shown here that these modes can be observed clearly in dilute alloy samples, and appropriate experimental geometries for this are identified.…”

“…4a, c. Fitting of these spectra reveals that all bands shift to higher frequency by about 1% with respect to the corresponding modes of ReSe 2 , confirming the incorporation of sulfur. This shift is known 43 and, over the whole composition range, is approximately linear. It is reproduced in our calculations and is principally accounted for by the mass difference of the chalcogen atoms 47 though, interestingly, the sulfur site plays a role; the calculated shifts of representative lattice modes ( Supplementary Fig.…”

Recent advances in low‐dimensional semiconductor nanomaterials and their applications in high‐performance photodetectors

“…Continuous control of the properties of the material can be achieved by fusing two or more different types of materials with different proportion of the components in the material . For example, continuously tunable bandgap in an alloy can achieve a broad spectral response, which has greater application in the field of optoelectronics . Moreover, the preparation of alloy nanosheets with adjustable components also greatly enriches the system of TMDs material, providing more options and possibilities for device optimization and application.…”

“…15,16 For example, continuously tunable bandgap in an alloy can achieve a broad spectral response, which has greater application in the field of optoelectronics. 15,[17][18][19][20][21][22][23] Moreover, the preparation of alloy nanosheets with adjustable components also greatly enriches the system of TMDs material, providing more options and possibilities for device optimization and application.…”

Exploiting Anisotropy of Plasmonic Nanostructures with Polarization Modulation Infrared Linear Dichroism Microscopy (µPM‐IRLD)

“…When combined with microscopy, polarized light measurements can yield critical information about the orientation of crystallographic axes in microstructures or enable the ability to map the distribution of anisotropic domains . Raman, infrared, and sum‐frequency generation are examples of vibrational spectroscopies that yield molecular anisotropy information using a set of polarized measurements . Noteworthy, polarized spectroscopic measurements can be of interest to probe metamaterials, such as plasmonic nanostructures, that exhibit an anisotropic response under polarized light …”