报告题目：Germanene: the germanium analogue of graphene
报告人：张利杰，University of Twente, Netherlands
时 间：2月22日（周三）上午 10:30-11:30
地 点：唐仲英楼 B501
报告摘要: Germanene, a monolayer allotrope of germanium atoms arranged in a honeycomb structure, is the germanium analogue of graphene. Here in this talk, I will show that two different ways to synthesis germanene. The deposition of several monolayers of Pt on Ge(110) followed by annealing at 1100 K results in the formation of three-dimensional eutectic GePt nanocrystals. Upon cooling down these eutectic GePt nanocrystals phase separate into pure Ge2Pt and Ge phases. The Ge segregrates towards the surface and forms a germanene layer and with a 2D Dirac signature. In the second part I will show the successful synthesis of germanene on molybdenum disulfide (MoS2), a band gap material. Preexisting defects in the MoS2 surface act as preferential nucleation sites for the germanene islands. The lattice constant of the germanene layer (3.8±0.2A) is about 20% larger than the lattice constant of the MoS2 substrate (3.16A). Scanning tunneling spectroscopy measurements and density functional theory calculations are in a good agreement revealing that the linearly dispersing bands at the K points.
报告人简介：张利杰，2013年9月起于荷兰特文特大学（University of Twente）MESA+纳米技术研究所攻读博士学位。主要研究方向：超高真空扫描隧道显微镜及显微谱（STM/STS）；新型二维晶体材料锗烯的制备、结构及物性。截至目前已在PRL，APL等期刊发表论文多篇。