arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1008.3606cond-mat.mes-hall
收藏

石墨烯局域隧道谱中的尖端诱导掺杂效应

Tip induced doping effects in local tunnel spectra of graphene

Shyam K. Choudhury, Anjan K. Gupta

摘要:

利用室温扫描隧道显微镜和光谱仪(STM/S)研究了具有可调背栅的单层石墨烯(SLG)的尖端诱导掺杂局域隧道谱。用剥离法在二氧化硅表面制备的SLG样品经拉曼光谱证实,具有原子分辨的蜂窝状晶格结构。局部隧道谱显示两个极小值,在背栅掺杂的情况下,两者的位置都有明显的演变。由于电荷的不均匀性,在空间上也观察到类似的光谱变化。随着掺杂,两个最小值在相反的方向上移动,其中一个显示出接近平方根的依赖性,另一个显示出对栅极电压的线性依赖性。我们解释这些功能所产生的STM尖端诱导和偏置电压依赖的SLG掺杂。

英文摘要:

We report on tip induced doping in local tunnel spectra of single layer graphene (SLG) with tunable back-gate using room temperature scanning tunneling microscopy and spectroscopy (STM/S). The SLG samples, prepared on silicon dioxide surface by exfoliation method and verified by Raman spectra, show atomically resolved honeycomb lattice. Local tunnel spectra show two minima with a clear evolution in the position of both with doping by the back gate. A similar variation in spectra is also observed spatially due to charge inhomogeneity. With doping the two minima move in opposite directions with one showing nearly a square root dependence and the other a linear dependence on gate voltage. We explain these features as arising from the STM tip induced and bias voltage dependent doping in SLG.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑