• 文献标题:   Functional silicene and stanene nanoribbons compared to graphene: electronic structure and transport
  • 文献类型:   Article
  • 作  者:   VAN DEN BROEK B, HOUSSA M, IORDANIDOU K, POURTOIS G, AFANAS EV VV, STESMANS A
  • 作者关键词:   2d material, silicene, stanene, armchair ribbon, electronic functionalization, ballistic transport
  • 出版物名称:   2D MATERIALS
  • ISSN:   2053-1583
  • 通讯作者地址:   Katholieke Univ Leuven
  • 被引频次:   17
  • DOI:   10.1088/2053-1583/3/1/015001
  • 出版年:   2016

▎ 摘  要

Since the advent of graphene, other 2D materials have garnered interest; notably the single element materials silicene, germanene, and stanene. Weinvestigate the ballistic current-voltage (I-V) characteristics of armchair silicene and stanene armchair nanoribbons (AXNRs with X = Si, Sn) using a combination of density functional theory and non-equilibrium Green's functions. The impact of out-of-plane electric field and in-plane uniaxial strain on the ribbon geometries, electronic structure, and (I-V)s are considered and contrasted with graphene. Since silicene and stanene are sp(2)/sp(3) buckled layers, the electronic structure can be tuned by an electric field that breaks the sublattice symmetry, an effect absent in graphene. This decreases the current by similar to 50% for Sn, since it has the largest buckling. Uniaxial straining of the ballistic channel affects the AXNR electronic structure in multiple ways: it changes the bandgap and associated effective carrier mass, and creates a local buckling distortion at the lead-channel interface which induces a interface dipole. Due to the increasing sp(3) hybridization character with increasing element mass, large reconstructions rectify the strained systems, an effect absent in sp(2) bonded graphene. This results in a smaller strain effect on the current: a decrease of 20% for Sn at 15% tensile strain compared to a similar to 75% decrease for C.