Strain effect on electronic structures of graphene nanoribbons: A first-principles study

Abstract

We report a first-principles study on the electronic structures of deformed graphene nanoribbons (GNRs). Our theoretical results show that the electronic properties of zigzag GNRs are not sensitive to uniaxial strain, while the energy gap modification of armchair GNRs (AGNRs) as a function of uniaxial strain displays a nonmonotonic relationship with a zigzag pattern. The subband spacings and spatial distributions of the AGNRs can be tuned by applying an external strain. Scanning tunneling microscopy dI/dV maps can be used to characterize the nature of the strain states, compressive or tensile, of AGNRs. In addition, we find that the nearest neighbor hopping integrals between pi-orbitals of carbon atoms are responsible for energy gap modification under uniaxial strain based on our tight binding approximation simulations.

Graphene Nanoribbons: Geometric, Electronic, and Magnetic Properties

“…3. (Sun et al 2008), there are four important subbands which dominate the electronic behaviors of armchair GNRs. These subbands are constituted by the π bonds of carbon atoms, and have different shapes, which provide the possibility of external modulations, such as strain.…”

“…Thus, how are the geometric structures and the related electronic structures deformed under external strain becomes interesting problems. Sun et al have carried out comprehensive DFT studies to investigate those problems (Sun et al 2008). To clearly indicate such effect, the deformation of armchair GNRs can be represented by the strain (ε), defined as ε = (r-r 0 )/ r 0 , where r and r 0 are the deformed and initial equilibrium lattice constants (r 0 = 4.287 Å) along the periodic direction of armchair GNRs.…”

Theoretical investigation of the electronic structures and carrier transport of hybrid graphene and boron nitride nanostructure

“…3(d) strain-free point because of the stringent point in the band edge shift as a function of applied uniaxial strain. 28,29 In our cases this will lead to very small DP (usually smaller than 1) for electron carriers of N = 3i (N > 9) and hole carriers of N = 3i + 1 (N > 4) giving rise to very large carrier mobility according to Eq. (1).…”

I-V characteristics of in-plane and out-of-plane strained edge-hydrogenated armchair graphene nanoribbons

“…Particularly, strain studies on graphene nanoribbons are gaining much attention as the control of their mechanical deformation could allow the creation of novel devices for energy harvesting [83][84][85][86] . There exist many reports on the electronic structure modification via strain engineering of simulated systems of different edge type, edge decoration, shape, and width [46][47][48][49][50][87][88][89][90][91][92][93][94][95][96] . Among those researchers, some outstand by including analyses of the current-voltage characteristics 43,44,92,97,98 .…”

“…There is an increasing interest in examining their mechanical [36][37][38][39][40][41][42][43][44][45][46][47] and electronic properties [48][49][50][51][52][53][54][55][56][57][58] under different constrains such as tensile stress to predict the behavior of future possible devices. Particularly, strain studies on graphene nanoribbons are gaining much attention as the control of their mechanical deformation could allow the creation of novel devices for energy harvesting [83][84][85][86] .…”