MoS_2电子结构、振动和介电性质的第一性原理计算

采用基于密度泛函理论的第一性原理,研究了MoS2电子结构、振动和介电性质,得到了MoS2能带结构、态密度、介电谱和红外反射谱。研究表明,MoS2为间接带隙半导体。介电张量在垂直和平行于c轴方向表现出强烈的各向异性。电子屏蔽作用对介电常数贡献较强,晶格振动对介电常数贡献较弱。在300~500 cm-1波段,由于红外光学模的存在,材料与电磁波存在较强的相互作用,透波性能较差。

First-Principles Study of Electronic Structure, Vibrational and Dielectric Properties of MoS2

The electronic structure, vibrational and dielectric properties of MoS2 were studied by first-principles based on density functional theory (DFT). The band structure, density of states, the dielectric function spectrum and the infrared reflectivity spectrum were presented. The results indicate that MoS2 is a semiconductor with indirect band gap. The dielectric tensors are highly anisotropic. It is found that lattice vibration makes less contribution to the dielectric constant than that of electronic screening. Due to the existence of Infrared active modes over the range of 300~500 cm-1, there is a strong interaction between the material and electromagnetic wave, impairing the wave-transparent properties of MoS2.