Stability, defect and electronic properties of graphane-like carbon-halogen compounds

• Published in: Chinese physics B Vol. 20; no. 11; pp. 512 - 518
• Main Author: 陆地 杨玉荣 肖杨 张晓禹
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.11.2011
• Subjects: Atomic structure; CBR; Electronic properties; Energy gaps (solid state); Graphene; Halogens; Mathematical analysis; Semiconductors; Stability; 分子动力学模拟; 化合物; 电子性质; 电子结构; 碳原子; 稳定性; 缺陷
• ISSN: 1674-1056; 2058-3834
• DOI: 10.1088/1674-1056/20/11/118101

We perform first-principles total energy calculations to investigate the stabilities and the electronic structures of graphane-like structures of carbon-halogen compounds, where the hydrogen atoms in the graphane are substituted by halogen atoms. Three halogen elements, fluorine （F）, chlorine （C1） and bromine （Br）, are considered, and the graphane-like structures are named as CF, CC1 and CBr, respectively. It is found that for the single-atom adsorption, only the F adatom can be chemically adsorbed on the graphene. However, the stable graphane-like structures of CF, CC1 and CBr can form due to the interaction between the halogen atoms. The carbon atoms in the stable CF, CC1 and CBr compounds are in the sp3 hybridization, forming a hexagonal network similar to the graphane. The electronic band calculations show that CF and CC1 are semiconductors with band gaps of 3.28 eV and 1.66 eV, respectively, while CBr is a metal. Moreover, the molecular dynamics simulation is employed to clarify the stabilities of CF and CC1. Those two compounds are stable at room temperature. A high temperature （：〉 1200 K） is needed to damage CF, while CC1 is destroyed at 700 K. Furthermore, the effects of a vacancy on the structure and the electronic property of CF are discussed.