The mechanism of the modulation of electronic anisotropy in two-dimensional ReS₂

Abstract

The electronic anisotropy in ReS2 is highly adjustable due to the angle-dependent scattering induced by defects/vacancies at a low carrier density.

Ultrahigh Anisotropic Transport Properties of Black Phosphorus Field Effect Transistors Realized by Edge Contact

“…C with top contact along AC and ZZ at 300 K. It is observed that the increasing rates of conductance are different along AC and ZZ due to the anisotropic atomic structure of BP, showing a maximum anisotropic conductance of ≈1.096 at V gs = −30 V. This low value of conductance anisotropy of Sample C with top contact can be attributed to the uniform doping along the AC and ZZ directions. [37] Furthermore, the scattering rate may be same along the AC and ZZ directions due to the uniform carrier density, resulting in a similar gate modulation along the AC and ZZ directions in Sample C with top contact (Figure 4a). [37] Table 1 displays the conductance and mobility anisotropies of BP FETs obtained in this work as well as those reported in previous experimental and theoretical works.…”

“…[37] Furthermore, the scattering rate may be same along the AC and ZZ directions due to the uniform carrier density, resulting in a similar gate modulation along the AC and ZZ directions in Sample C with top contact (Figure 4a). [37] Table 1 displays the conductance and mobility anisotropies of BP FETs obtained in this work as well as those reported in previous experimental and theoretical works. Table 1 shows that the conductance anisotropy of our Sample C with top contact is smaller than those of previous works.…”

2D Re‐Based Transition Metal Chalcogenides: Progress, Challenges, and Opportunities

“…Presently, several research works have explored the defects in ReX 2 and their effect on its phase structure, anisotropy electrical transport and the catalysis properties. [15,103,[120][121][122] For instance, chalcogen-deficiency mediated structure transformation of ReS 2 shows that the sulfur atom loss reduces the spacing between two Re diamond chains by 20.6% from the original value (≈0.34 nm) in the b direction to form more constricted structure (≈0.27 nm). [15] Such sulfur deficiency can also give rise to a distinct phase transformation in the a direction.…”

“…Different from conventional isotropic 2D materials like MoS 2 , the effective mass of electron and hole of ReX 2 varies along different crystal directions owing to the unusual low-symmetry crystal structure. [15,120,162] It affords ReX 2 inspiring 2D in-plane anisotropic electronic properties which have been revealed by fabricating ReX 2 FETs with multipair probes configuration and performing angle-resolved transport measurements. For example, Suenaga and coworkers investigated the relationship between crystalline orientation of ReS 2 and the electron transport by combination of transport measurement and transmission electron microscopy (Figure 10g,h).…”

“…[ 103 ] Zhai and coworkers found the electronic anisotropy of CVD‐grown bilayer ReS 2 can be largely adjustable, which is attributed to the angle‐dependent scattering from defects or vacancies. [ 120 ] Furthermore, the abundant Re atoms vacancies with lower Gibbs free energy for H adsorption activate the inert basal plane of ReS 2 as highly active sites for hydrogen evolution reaction. [ 122 ] Notably, owing to the distorted 1T structure of ReX 2 , the six X atoms bonded to one Re atoms are inequivalent in space, and the four Re atoms in one Re4 cluster are also inequivalent.…”