Electronic states, mechanical properties and doping effects of one-dimensional atomic wires of SiX2 (X = S, Se)

Abstract

Low dimensional materials especially one-dimensional (1D) systems demonstrate uniquely electrical, optical, mechanical properties and promising applications in nanometer even sub-nanometer devices. So far, few 1D systems with width in atomic scale have been reported, which severely limits the applications of 1D materials. In this work, 1D atomic wires (AWs) of SiX2 (X = S, Se) have been examined by using first-principles calculations based on density functional theory. The theoretical results demonstrate that 1D AWs of SiX2 are dynamically stable and feasible to be exfoliated with low exfoliation energies. Besides, they possess relatively high electron mobilities. Moreover, 1D AWs of SiX2 are prone to be curved and twisted accompanying with well ductility. In addition, n-type and p-type substitutional doping are proposed and examined. The band gap type transition from indirect to direct occurs in F-doped SiX2. These highly desirable properties make 1D AWs of SiX2 promising and applicable in future flexible microelectronic and optoelectronic devices.