Janus二维双层MoSSe/WSSe异质结光电性质的第一性原理研究

First-Principles Study on Photoelectric Properties of Janus Two-Dimensional Bilayer MoSSe/WSSe Heterostructures

通过第一性原理计算研究了四种二维双层MoSSe/WSSe范德瓦耳斯异质结的光电性质。声子谱表明四种结构具有可靠的热力学稳定性。根据堆垛方式的不同,双层MoSSe/WSSe异质结可以是间接或直接半导体。而且,两种Janus型MoSSe/WSSe异质结具有1.22和1.88 eV的适中带隙、显著的可见光吸收系数、跨越了水氧化还原电位的带边位置。因此,Janus型的MoSSe/WSSe异质结构在光催化水分解领域具有一定的应用前景。

The photoelectric properties of four two-dimensional bilayer MoSSe/WSSe van der Waals(vdW)heterostructures were investigated by the first-principles calculations.All four heterostructures have been conformed thermodynamic stable by the phonon spectra.Bilayer MoSSe/WSSe heterostructures can be indirect or direct semiconductor,depending on the stacking routes.Moreover,two Janus MoSSe/WSSe heterostructures show the suitable band gap of 1.22 and 1.88 eV,notable absorption index on the visible light,and band edge positions straddling the water redox potential.Therefore,Janus MoSSe/WSSe heterostructures are expected to have application prospects in the field of photocatalytic water decomposition.