拉伸作用对单层石墨片电子能隙的影响

Effect of the tensile force on the electronic energy gap of graphene sheets

基于紧束缚方法,在考虑最近邻相互作用的情况下,研究了拉伸锯齿型边和扶手型边单层石墨的能带结构,得到了两种类型单层石墨片的π电子能带及带隙与拉力的解析关系式.通过数值计算能够发现:拉力不但使单层石墨产生带隙,而且带隙随着拉力的增大而变宽,并且锯齿型比扶手型的带隙更易变宽.

The external force can make a graphene sheet tighten and change its electronic structure. By using the tight-binding method,the energy bands of graphene sheets with zigzag shaped edges and armchair shaped edges drawn by the tensile force are investigated based on considering the nearest-neighbor interaction,and the analytic relations between the energy gaps besides the energy bands of π-electrons for two types of graphene sheets and the tensile force are obtained. Through numerical calculation,we found that the energy gaps broaden as the tensile force increases besides that the tensile force can make graphene open an energy gap,and moreover,the energy gap of graphene with zigzag edges broadens more easily.