【作者】 邹燕；

【导师】 苏希玉； 李峰；

【作者基本信息】 曲阜师范大学 ， 凝聚态物理， 2011， 硕士

【摘要】 自2004年英国曼彻斯特大学的安德烈·海姆(Andre Geim)和康斯坦汀·诺沃肖洛夫(Konstantin Novoselov)在实验上首次获得石墨烯以来,它以优异的力学、热学和电学性能,迅速成为近年来材料科学和凝聚态物理领域的研究热点之一。实验和理论上一致认为石墨烯是一种非常重要的气敏材料,可以用来探测许多气体分子。本文采用密度泛函理论研究了石墨烯和Si掺杂石墨烯吸附气体分子(CO、H2O、NO、NO2和O2)后所具有的结构及电子特性,进而探索石墨烯在气体探测领域的潜在应用价值。研究结果表明：纯净石墨烯对NO、NO2和O2比较敏感,吸附后其电子结构发生变化,对CO和H2O不敏感,吸附后其电子结构没有发生变化。与纯净的石墨烯相比较,Si掺杂石墨烯在对CO、H2O、NO、NO2和O2吸附中表现的更为活跃,Si掺杂石墨烯与吸附的气体分子之间强大的相互作用导致其电子特性和电导发生变化。因此Si掺杂石墨烯可以作为气敏材料来检测CO、H2O、NO、NO2和O2。本论文包含两部分,第一部分介绍研究工作所涉及的理论方法,第二部分介绍本人在攻读硕士学位期间所做的研究工作。分别介绍如下：1.研究工作所涉及的理论方法本论文第二章简单介绍了密度泛函理论。密度泛函理论是一种研究多电子体系性能的量子力学方法。由于其对经验参数没有任何的依赖性而且具有非常广泛的应用价值,可以计算材料的结构性质、机械性质、电学性质、光学性质、磁学性质等多方面的性能。论文在第三章中介绍了纯净的石墨烯基本结构、性质和应用。2、石墨烯/Si掺杂石墨烯的气敏特性研究第四章介绍了纯净石墨烯吸附气体后复合体的构型和电子特性；第五章介绍了Si掺杂石墨烯吸附气体后复合体所具有的几何结构及电子性质。研究结果表明,掺杂Si之后的石墨烯与纯净石墨烯相比其电子结构发生显著变化并且具有较高的气敏特性。更多还原

【Abstract】 Graphene is a new carbon-based material and first made successfully in the laboratory by Andre Geim and Konstantin Novoselov in the University of Manchester, UK in 2004. Because of its outstanding mechanical, thermal and electrical properties, it quickly became the research focus in the field of materials science and condensed matter physics in recent years. Many experiment and theory studies indicated that graphene is a good candidate for usage as gas sensor materials to detect various molecules. In order to exploit the potential applications of graphene as gas sensors, the adsorptions of a series of small gas molecules (such as CO、H2O、NO、NO2 and O2) on pristine graphene (PG) and Si-doped graphene (SiG) have been investigated by ab initio calculations. Our results indicate that the electronic properties of PG are sensitive to NO、NO2 and O2 molecules, but not changed much by the adsorption of CO and H2O molecules. Compared with PG, SiG is much more reactive in the adsorption of CO、H2O、NO、NO2 and O2. The strong interactions between SiG and the adsorbed molecules induce dramatic changes to the electronic properties and electrical conductance of SiG. Therefore, we suggest that SiG could be a good gas sensor for CO、H2O、NO、NO2 and O2In this thesis, the density functional calculations were performed to investigate the atomic and electronic structures of Graphene and Si-doped Graphene adsorbed with gas molecules. The theoretical fundamentals, which were used in our research work, were introduced in the first part. The main work done during my master’s study is introduced in second part. Introductions as follows:1. Theoretical basis used in researchesIn the second chapter of this thesis, the basic principles for density functional theory (DFT) were introduced. DFT based on first principles methods is a more important method, which can be used to investigate the structure, mechanical, electronic, magnetic and optical properties of small systems, without depending on any empirical parameters. In the third chapter of the thesis, we introduced the structures, the properties and the applications of pristine graphene.2. Theoretical study of graphene and Si-doped grapheneIn the fourth chapter and the fifth chapter, we investigated the atomic and electronic structures of pristine graphene and Si-doped graphene adsorbed with gas molecules, respectively. We found that Si-doped graphene have significantly changed the electronic structures of graphene and improved the gas sensoring to gas molecules.更多还原