arXiv subjects

L. Z. Liu

Publications and source records attributed to L. Z. Liu.

4 recordsLinked to original sources

arXiv2025

Regulation of electronic structures in ReSeS monolayer with anisotropic deformations

Because of their unique and rich physical properties, transition metal dichalcogenides (TMDs) materials have attracted much interest. Many studies suggest that introducing the degree of freedom of anisotropy, which may be brought about by low structural symmetry, might further optimize their applications in industry and manufacturing. However, most currently reported TMDs do not achieve the theoretical minimum symmetry. Utilizing the first principles calculation, we present ReSeS monolayer with a Janus structure. Results indicate that its electronic dispersion is sensitive to structural distortions, which increases metallicity. Our reduction-Hamiltonian can provide a qualitative description, but further analyses reveal that bonding/antibonding properties near the Fermi surface are the more fundamental cause of the variations. Furthermore, geometric deformations can regulate the effective mass of electrons as well as the spectroscopic response, resulting in anisotropic behaviors. Our ideas serve as a foundation for developing new regulable optoelectronic devices.

cond-mat.mtrl-sci↗

arXiv2016

Electronic Structure and Optical Properties of Monolayer $ReS_2$ with Defect Controlled by Strain Engineering

By using first-principles calculations, we investigated the monolayer $ReS_2$ with vacancies under strain engineering, specifically focusing on its energy of formation, band gap, electron density of states, effective mass and optical properties. The calculated results disclose that S4 defect is more likely to form than other kinds of vacancies. Asymmetric deformation induced by strain makes its band structure transformation from direct band gap to indirect band gap. The analysis of the partial density of states indicates that the Re-d, Re-p and S-d orbitals are the major components of the defect states, being different from $MoS_2$, the defect states locate both above and below the Fermi level. Moreover, the effective mass was sensitive and anisotropic under the external strain. The reflection spectrum can be greatly tuned by the external strains, which indicates that the ReS2 monolayer has promising applications in nanoscale strain sensor and conductance-switch FETs.

cond-mat.mtrl-sci↗

arXiv2016

Regulation of oxygen vacancy types on SnO2 (110) surface by external strain

In tin dioxide nanostructures, oxygen vacancies (OVs) play an important role in their optical properties and thus regulation of both OV concentration and type via external strain is crucial to exploration of more applications. First-principle calculations of SnO2 (110) surface disclose that asymmetric deformations induced by external strain not only lead to its intrinsic surface elastic changes, but also result in different OV formation energy. In the absence of external strain, the energetically favorable oxygen vacancies (EFOV) appear in the bridging site of second layer. When -3.5% external strain is applied along y direction, the EFOV moves into plane site. This can be ascribed that the compressed deformation gives rise to redistribution of electronic wave function near OVs, therefore, formation of newly bond structures. Our results suggest that different type OVs in SnO2 surface can be controlled by strain engineering.

cond-mat.mes-hall↗

arXiv2016

Anisotropic Raman Scattering and Mobility in Monolayer 1Td-ReS2 Controlled by Strain Engineering

Regulation of electronic structure and mobility cut-on rate in two-dimensional transition metal dichalcogenides (TMDs) has attracted much attention because of its potential in electronic device design. The anisotropic Raman scattering and mobility cut-on rate of monolayer unique distorted-1T(1Td) ReS2 with external strain are determined theoretically based on the density function theory. The angle-dependent Raman spectrum of Ag-like, Eg-like and Cp models are used to discriminate and analysis structural anisotropy; the strain is exploited to adjust the structural symmetry and electronic structure of ReS2 so as to enhance mobility cut-on rate to almost 6 times of the original value. Our results suggest the use of the strain engineering in high-quality semiconductor switch device.

cond-mat.mes-hall↗