The structural and thermal properties of bulk Td-WTe 2 have been studied by using first-principles calculations based on the simple Klemens model and an iterative self-consistent method. Both methods show that lattice thermal conductivity is anisotropic, with the highest value in the (001) plane, and lowest one along the c-axis at 300 K. The calculated average thermal conductivity of WTe 2 is in agreement with the experimental measurement. The size dependent thermal conductivity shows that nanostructuring of WTe 2 can possibly further decrease the lattice thermal conductivity, which can improve the thermoelectric efficiency. Such extremely low thermal conductivity, even much lower than WSe 2 , makes WTe 2 having many potential applications in thermal insulation and thermoelectric materials.

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In a recent accomplishment, a new two-dimensional allotrope of carbon-biphenylene (BP) was experimentally synthesized [Fan et al., Science, 372, 852-856 (2021)]. The BP sheet is composed of four-, six-, and...

Lateral heterostructures by combining various two-dimensional crystals have emerged as an exciting way to tailor their properties for new-generation optoelectronic devices. Herein, a seamless lateral heterostructure based on MoSi2N4 and...

Structure and electronic properties of Zn(1-x)(LiGa)(0.5x)O are examined by first-principles methods. The calculations indicate that stable forms of Zn(1−x)(LiGa)(0.5x)O alloys may have different space groups with their parent materials. Our results show the orthorhombic lattices with Pm, Pmn21, and P1 structures have lower formation energies than the wurtzite lattices at a given (LiGa)0.5 composition. The band-gap energies of Zn(1−x)(LiGa)(0.5x)O in the wurtzite and orthorhombic structure are nearly identical and all compounds have direct band gaps. The gap widens as the (LiGa)0.5 concentration increases due to a weaker hybridization of O2 p and Zn 3d and stronger bonding–antibonding interaction between Zn 4 s (Ga 4 s, Li 2 s) and O 2p. Zn(1-x)(LiGa)(0.5x)O alloys have potential for applications such as ultraviolet (UV) light emitting devices and highly sensitive UV detectors to replace Zn1-xMgxO and Zn1-xBexO alloys due to the stable lattice structures and low band gap bowing.