二维WS/ZnO范德华异质结构的光电特性及应变调控
Optoelectronic properties and strain regulation of the 2D WS/ZnO van der Waals heterostructure.
作者信息
Guan Yujun, Yao Hui, Zhan Huahan, Wang Hao, Zhou Yinghui, Kang Junyong
机构信息
Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, CI Center for OSED, College of Physics Science and Technology, Xiamen University Xiamen 361005 P.R. China
Research Institute for Biomimetics and Soft Matter, Xiamen University Xiamen 361005 P.R. China.
出版信息
RSC Adv. 2021 Apr 15;11(23):14085-14092. doi: 10.1039/d1ra01877a. eCollection 2021 Apr 13.
The combination of zinc oxide (ZnO) and transition metal dichalcogenide (TMD) nanoparticles has higher photocatalytic efficiency and field emission performance than TMDs or ZnO, as well as significantly higher water cracking photocatalytic activity. By first-principles calculation, we investigated the structural and optoelectronic properties of the two-dimensional (2D) WS/ZnO van der Waals (vdWs) heterostructure, and the regulation effect of biaxial strain. It is revealed that the conduction-band minimum (CBM) is lower than the reduction potential of water (H ≈ -4.44 eV), and the valence-band maximum (VBM) is lower than the oxidation potential ( ≈ -5.67 eV), thus the heterostructure is a good oxidant in the water decomposition process, but cannot match the requirements for water reduction. By applying a -2% biaxial strain, the CBM is elevated to a position higher than the reduction potential of water, then the 2D vdWs WS/ZnO heterostructure becomes a good material for the application of water reduction and other photovoltaic and photocatalytic devices.
氧化锌（ZnO）与过渡金属二硫属化物（TMD）纳米颗粒的组合具有比TMD或ZnO更高的光催化效率和场发射性能，以及显著更高的水裂解光催化活性。通过第一性原理计算，我们研究了二维（2D）WS/ZnO范德华（vdWs）异质结构的结构和光电性质，以及双轴应变的调节作用。结果表明，导带最小值（CBM）低于水的还原电位（H≈-4.44 eV），价带最大值（VBM）低于氧化电位（≈-5.67 eV），因此该异质结构在水分解过程中是一种良好的氧化剂，但不符合水还原的要求。通过施加-2%的双轴应变，CBM升高到高于水还原电位的位置，此时二维vdWs WS/ZnO异质结构成为用于水还原及其他光伏和光催化器件应用的良好材料。
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