二硫化钼薄膜的制备和性质研究

Preparation and Properties of MoS2 Thin Film

摘要:

基于第一性原理,应用Materials Studio软件对2H-MoS₂的能带结构、态密度、光学特性等进行了模拟研究。结果表明:MoS₂是间接带隙半导体,禁带宽度约为1.1275eV；材料在紫外至可见光波段具有一定吸收,吸收系数随波长增加而减小,拉曼光谱在375和400cm-1分别出现了E¹_2g和A_1g两个振动模式。在39.5°,33.5°等位置处出现了(103),(101)等晶面的衍射峰。采用磁控溅射的方法,在石英衬底上制备了不同厚度的MoS₂薄膜,发现该薄膜具有(101)择优取向,在375和407cm-1处也分别出现了E¹_2g和A_1g两个拉曼峰。随着厚度的增加,薄膜在可见光波段透过率下降,光学带隙向长波长移动,模拟结果与实验结果基本吻合。

Abstract:

Based on the first principles, the materials studio software was used to simulate the energy band structure, density of states, and optics properties of 2H-MoS₂. The results show that MoS₂ was an indirect band gap semiconductor with a band gap of about 1.25eV; the material had a certain absorption in the ultraviolet to visible wavelength range, and the absorption coefficient decreases with the increase of wavelength. Raman spectra showed E¹_2g and A_1g vibration modes at 375 and 400cm-1, respectively. Typical diffraction peaks such as (103) and (101) appeared at the positions 39.5° and 33.5°. Magnetron sputtering method was also used to prepare MoS₂ films with different thicknesses on a quartz substrate in this paper. It was found that the film had (101) preferred orientation, E¹_2g and A_1g were also presented at 375 and 407cm-1 in the Raman spectrum. As the film thickness increased, the transmittance of the film in the visible light band decreased, and the optical band gap shifted toward longer wavelengths. The simulation results were basically in agreement with the experimental results.