表面氢化双层硅烯的结构和电子性质

摘要

Using the density functional theory (DFT) with both the generalized gradient approximation (GGA) and HSE06 hybrid functional calculation, we have investigated the structural and electronic properties of hydrogenated bilayer silicene. Results show that the hydrogenated bilayer silicene may have three configurations: AA-chair-like, AB-chair-like and AA-boat-like forms; after hydrogenation the material properties change from zero band gap semimetal into an indirect band gap semiconductor with forbidden band widths of 1.208, 1.437, and 1.111 eV. We have performed a hybrid HSB06 functional calculation and the correction for the band gaps: 1.595, 1.785, and 1.592 eV. Further analysis of the hydrogenated bilayer silicene with a strained band gap, the relationship between strain and the band gap can be continuously adjusted. Possible applications may be found in future nano-electronic devices.%采用密度泛函理论(DFT)广义梯度近似GGA和HSB06方法研究了氢化双层硅烯(silicene)的结构和电子性质,结果表明：氢化后的双层硅烯可能存在三种稳定的构型, AA椅型、AB椅型和AA船型,其中AA椅型和AB椅型结构最为稳定,氢化后这三种稳定构型材料的性质由零带隙的半金属(semimetal)转变为禁带宽度分别为1.208,1.437和1.111 eV的间接带隙的半导体,采用混合泛函HSB06计算修正得到的带隙分别为1.595,1.785和1.592 eV.进一步分析了在双轴应变下氢化双层硅烯的带隙随应变的关系,得到应变可以连续的调节材料的带隙宽度,这些性质有可能应用于未来的纳米电子器件.