翘曲度对锗烯的电子结构及光学性质的影响

Effect of Warpage on Electronic Structure and Optical Properties of Germanene

本文采用基于密度泛函理论的第一性原理方法研究不同翘曲度下锗烯的电子结构及光学性质,分析翘曲度对电子结构及光学性质的影响。采用六种不同的近似方法对锗烯的几何结构进行优化,得到最稳定的结构体系,在此基础上选取不同的翘曲度,并对翘曲度的稳定性进行论证得到三种较稳定的翘曲结构。通过翘曲度的调节打开锗烯的带隙,并且通过调节翘曲度实现锗烯带隙在间接带隙和直接带隙之间的转化,通过分析态密度解释了能带结构的调控机制,以及翘曲度对锗烯光学性质的影响。研究表明翘曲度能够有效地调控锗烯的电子结构和光学性质,提高光电子利用效率。

In this paper,the first-principles method based on density functional theory was used to study the electronic structure and optical properties of germanene at different warpage,and the influence of warpage on electronic structure and optical properties was analyzed.Six different approximation methods were used to optimize the geometric structure of germanene,and the most stable structure system was obtained.On this basis,different warping structures were selected,and the stability of warping degree was demonstrated,and three stable warping structures were obtained.The band gap of germanene is opened by adjusting the warping degree,and the conversion between indirect band gap and direct band gap is realized by adjusting the warpage.The regulation mechanism of band structure and the effect of warpage on the optical properties of germanene are explained by analyzing the density of states.The results show that the warpage can effectively regulate the electronic structure and optical properties of germanene,and improve the photoelectron utilization efficiency.