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Abstract In this study, we investigate systematically the effect of strain engineering and electric field on electronic properties of single-layer SnSe 2 using density functional theory. Our calculated results indicate that the single-layer SnSe2 is a semiconductor with a small band gap of 0.715 eV at the equilibrium state. The electronic states near the Fermi level are mainly contributed by Sn- d and Se- p orbitals, especially the contribution of the Se- p orbital to the valence band is dominant. Under biaxial strain, the band gap of the single-layer SnSe 2 changes abnormally. While compressive biaxial strain reduces band gap rapidly, the band gap of the single-layer SnSe 2 only increases slightly when increasing the tensile biaxial strain. In contrast to the strain-dependence case, the influence of the external electric field on the electronic properties of the single-layer SnSe 2 is quite small and the energy gap of the single-layer SnSe 2 does not depend on the direction of the perpendicular electric field. Our calculated results can provide more information for application possibility of the single-layer SnSe 2 in nanoelectronic devices. Highlights • Single-layer SnSe 2 is an indirect semiconductor with band gap of 0.715 eV at equilibrium. • Band gap of single-layer SnSe 2 depends strongly on the biaxial strain. • Effect of electric field on band gap of single-layer SnSe 2 is quite small. • Control of single-layer SnSe 2 band gap by strain is useful in nanoelectronic applications. [ABSTRACT FROM AUTHOR]

Monoatomic lattice of boron atoms (borophene), a new low-dimensional material shows promising physical and chemical properties. Recently, on the most stable borophene, metal β 12 -borophene, electronic phase transition from metal-to-semimetal and metal-to-semiconductor in the presence of perpendicular electric field and dilute charged impurity is found, respectively. From this point, in this paper, we study the magnetic properties of the electric field and charged impurity induced β 12 -borophene. Particularly, we have calculated Pauli spin paramagnetic susceptibility (PSPS) quantity using the five-band tight-binding Hamiltonian and the Green's function approach for different interaction-dependent models. The charged impurity and perpendicular electric field effects on the susceptibility of β 12 -borophene show that the "pristine" PSPS of inversion symmetric model in β 12 -borophene is larger than the homogeneous model as well as the Dirac fermions contribute to the total PSPS more than triplet fermions. Further, we found out that the dilute charged impurity does not influence PSPS of the principle system significantly at all temperatures and it decreases slightly with impurity concentration and scattering potential. On the other hand, electric field-induced PSPS results in an increasing (decreasing) trend for PSPS at very low (intermediate and high) temperatures. Our findings pave the way for the industrial practical applications. • The magnetic susceptibility of β 12 -borophene in the presence of a perpendicular electric field is investigated. • The anisotropic susceptibility is found near different points of the first Brillouin zone for different homogenous, inversion symmetric and inversion non-symmetric Hamiltonian models. • The "pristine" susceptibility of inversion symmetric model is larger than the homogenous model. • The Dirac fermions contribute to the total susceptibility more than triplet fermions. • Susceptibility does not change significantly with dilute charged impurity, while electric field alters susceptibility depending on the temperature. [ABSTRACT FROM AUTHOR]