硅烯的氢化及电子性质研究

发布时间：2018-05-03 01:03

本文选题：硅烯 + 扫描隧道显微镜　；参考：《云南大学》2015年硕士论文

【摘要】：自从1947年晶体管发明以来,以硅,锗等为基础的半导体工业得到了快速发展,极大的改善了人类的生活。这其中又以集成电路的发展最为迅猛,人们为了获得性能更高能耗更低的芯片,不断的缩减器件的尺寸,增加其集成度。相应的就需要一方面不断改善器件结构来降低材料的维度,另一方面,寻找新型材料。目前,以石墨烯,二硫化钼,硅烯等为代表的新型二维材料以及拓扑绝缘体引起了人们广泛的关注。这些材料因其新奇的量子效应,例如石墨烯其准粒子满足相对论协变的狄拉克方程,电子有效质量为零,这样在信息传输时基本不耗能,具有很大的应用前景。硅烯作为近年来刚刚兴起的一种类石墨烯材料,具有十分丰富的物理性质同时又与现代半导体工业相兼容,使其受到了学术界和工业界的关注。本论文中,我们主要通过分子束外延的方法在Ag(111)表面生长硅烯,然后在室温下,通过加热裂解钨丝来裂解氢气,使氢原子吸附在硅烯表面。随后使用扫描隧道显微镜对硅烯吸氢以后的结构及性质进行了详细的研究。本论文的主要内容如下： 1.利用分子束外延的方法在Ag(111)上生长硅烯,然后在室温下对不同的硅烯相,包括4x4,(?)×(?),(?)×(?)等进行吸氢。 2.利用扫描隧道显微镜观察不同相在氢化后结构的变化情况。结合第一性原理计算,给出了各个相的吸附构型。硅烯-4x4吸氢后从STM图像中可以看出它的结构依旧为有序的结构。吸氢后一个硅烯-4x4的单胞内包含有7个H原子,分属于两个不对称的半单胞之中,其中一个包含1个H原子,另一个包含6个H原子。对上述结构退火,大约在450K的时候,H完全从表面脱附掉。硅烯-(?)×(?)氢化后表面会出现有序的1×1结构,同时氢化后的结构说明了硅烯-(?)×(?)是一种硅烯相而非Si-Ag合金。 3.硅烯-(?)×(?)相根据吸氢量以及衬底温度的不同,出现了许多不同的结构。值得注意的是饱和吸氢的情况下,其表面会出现一些完整的1×1结构以及大量的条状结构。
[Abstract]:Since the invention of transistors in 1947, semiconductor industries based on silicon and germanium have developed rapidly and greatly improved human life. In order to obtain the chip with higher performance and lower energy consumption, the size of the device is reduced and the integration level is increased in order to obtain the chip with higher performance and lower energy consumption, which is the most rapid development of the integrated circuit. On the one hand, we need to improve the device structure to reduce the dimension of materials, on the other hand, to find new materials. At present, new two-dimensional materials, such as graphene, molybdenum disulfide, silicene, and topological insulators, have attracted much attention. Because of their novel quantum effects, such as graphene quasiparticle satisfying the Dirac equation of relativistic covariation, the effective mass of electrons is zero, so it has a great application prospect in the transmission of information. As a new kind of graphene material, silicene has rich physical properties and is compatible with modern semiconductor industry, which has attracted the attention of academia and industry. In this thesis, we have grown silicene on the surface of AgN 111 by molecular beam epitaxy (MBE). Then at room temperature, hydrogen atoms are adsorbed on the surface of silicene by heating pyrolytic tungsten wire to decompose hydrogen. The structure and properties of silicene after hydrogen absorption were studied by scanning tunneling microscope (SEM). The main contents of this thesis are as follows: 1. Silene was grown by molecular beam epitaxy (MBE) on AgC111), and then at room temperature for different silicene phases, including 4x4x4) 脳 Agnitrium). And so on to absorb hydrogen. 2. The structure changes of different phases after hydrogenation were observed by scanning tunneling microscope (SEM). According to the first principle calculation, the adsorption configuration of each phase is given. The structure of silicene-4 x 4 is still ordered by STM image. After hydrogen absorption, there are 7 H atoms in the monocytes of silylerene -4x4, belonging to two asymmetrical semi-monocytes, one containing one H atom and the other containing six H atoms. For the above structure annealing, H is completely desorbed from the surface at about 450 K. Silylidene) After hydrogenation, an ordered 1 脳 1 structure appears on the surface. It is a silicene phase rather than a Si-Ag alloy. 3. Silylidene) According to the amount of hydrogen absorption and substrate temperature, there are many different structures in the phase. It is worth noting that in the case of saturated hydrogen absorption, some complete 1 脳 1 structures and a large number of stripe structures appear on the surface.
【学位授予单位】：云南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN304.1

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