Hybrid functional studies on the optical and electronic properties of graphane and silicane. (May 2015)

• Record Type: Journal Article
• Authors: Hu, J.Q.; Zhang, J.H.; Wu, S.Q.; Zhu, Z.Z.
• Is Part Of: Solid state communications. Volume 209/210(2015)
• Page Start: 59
• Page End: 65
• Publication Date: 2015-05
• Subjects: A. Thin film -- D. Optical properties -- D. Electronic band structures; Solid state chemistry -- Periodicals; Solid state physics -- Periodicals; Chimie de l'état solide -- Périodiques; Physique de l'état solide -- Périodiques; 530.41
• DOI: 10.1016/j.ssc.2015.02.021
• Languages: English
• ISSNs: 0038-1098

Abstract

Abstract: The optical and electronic properties of graphane and silicane are studied by a first-principles method based on density functional theory, employing both the hybrid (HSE06) and the Perdew–Burke–Ernzerhof (PBE) functionals. Our HSE06 results show that graphane has a direct band gap of 4.49 eV, while silicane has an indirect band gap of 2.94 eV. In graphane, the imaginary part of dielectric function ε 2 ( ω ) has two peaks at 7.70 and 15.03 eV forE || z, while forE || x, there are three peaks lying at 11.56, 13.25 and 14.33 eV. In silicane, ε 2 ( ω ) has a main peak at 8.68 eV forE ||z, while there are two peaks at 4.56 and 8.55 eV forE ||x. In graphane, the peaks in ε 2 ( ω ) are mainly due to the transitions from C 2 p and H 1 s states to C 2 s and 2 p ones; while in silicane, the peaks are primarily originated from the transitions from Si 3 p and H 1 s states to Si 3 s and 3 p as well as H 1 s states. Highlights: Optical and electronic properties of graphane and silicane are studied with the first-principles method. Hybrid functional gives a wider valence band and an upward shift of the conduction bands. HSE06 functional predicted a more accurate band gap than the PBE one. Differences of the dielectric functions between graphane and silicane are noticed.