近年来二维材料的研究得到了极大的关注，尤其石墨烯中发现的新奇物性为科学上带来众多突破，然而石墨烯带隙为零，难以在传统微电子工业中起到主导地位。锗烯是类似石墨烯的新型二维材料，但不同于石墨烯的是其具有轻微的翘曲结构，这就为锗烯带隙的打开提供了可能。本项目根据我们前期在MoS2成功制备锗烯，并发现其狄拉克特性的研究基础上，选择几种过渡金属硫族化合物半导体衬底，制备近自由状态锗烯。利用低温强磁场扫描隧道显微镜探测锗烯在强磁场下的朗道能级量子化这一狄拉克材料特性。通过氢化的方式探索锗烯能带调控特性，根据锗烯对空气敏感性这一特点发展超高真空原位封装技术，最后对锗烯及氢化锗烯场效应晶体管的特性做初步的探索。期待得到锗烯预言中的输运双极特性及高载流子迁移率，为未来在微电子工业中的应用打下基础。

Recently a new exciting class of materials has been developed, which is not three-dimensional, but two-dimensional in nature. The most famous example of this new class of materials is graphene. Graphene exhibits a wealth of exotic and intriguing properties, which have resulted in a myriad of scientific breakthroughs. Despite all its beautiful properties graphene also has a severe downside: it is gapless, implying that graphene cannot be used to realize field-effect transistors and therefore graphene cannot take over the leading role that conventional semiconductors play in the current microelectronic industry. In this proposal, we aim to realize a germanene transistor. Germanene, i.e. the germanium analog of graphene, shares many properties with graphene, but in contrast to graphene, the honeycomb lattice of germanene is not planar but buckled. This buckling is the gateway to the opening and manipulation of a band gap in germanene. Unfortunately, germanene does not occur in nature and therefore it needs to be synthesized, preferably on a band gap material in order to electronically decouple germanene from the substrate. We explore the Landau level by using low temperature high magnetic field scanning tunneling microscopy. A sizable band gap will be opened in germanene via the application of an external electric field or hydrogenation. According to the characteristics of germanene to air sensitivity, ultra-high vacuum in-situ encapsulation technology was developed. Finally, the properties of germanene and hydrogenated germanene field effect transistors were explored. We expect the bipolar transport characteristics and high carrier mobility of germanene based transistors beneficial for future industrial applications.