Formation, Stability, Geometry and Band Structure of Organically Surface-Modified Germanane

• 来源期刊: 材料科学技术（英文版）
• 年，卷（期）: 2017,（1）
• 页码范围: 59-64
• 页数: 6页
• 语种: 英文

摘要

Surface modification may be an effective means for controlling the properties of germanane,i.e.,hydrogenated germanene.In this work,we investigate the formation,stability,structure and electronic properties of surface-modified germanane that results from the hydrogermylation,alkoxylation,aminization or phenylation of germanane.By assuming the typical organic surface coverage of ～33％,we have compared organically surface-modified germanane with germanene and germanane in the framework of density functional theory.It is found that organically surface-modified germanane may all stably exist despite the endothermic nature of organic surface modification.Organic surface modification leads to the decrease of the Ge-Ge bond length and the Ge-Ge--Ge bond angle of germanane,while causing the buckling distance of germanane to increase.Hydrogenation makes germanene change from a semimetal to a directbandgap semiconductor.Organic surface modification further impacts the band structure of the resulting germanane.Hydrogermylated/alkoxylated germanane is a direct-bandgap semiconductor,while aminated/phenylated germanane is an indirect-bandgap semiconductor.All the organic surface modification gives rise to the increase of the bandgap of germanane.