期刊
PHYSICAL REVIEW B
卷 78, 期 12, 页码 -出版社
AMER PHYSICAL SOC
DOI: 10.1103/PhysRevB.78.121402
关键词
-
资金
- Office of Naval Research [N00014-02-1-0986]
- William R. and Sara Hart Kimball Stanford Graduate Grant
- National Science Foundation
- Stanford Nanofabrication Facility of NNIN
- National Science Foundation [ECS-9731293]
- Air Force Office of Scientific Research [FA9550-04-1-0384, F49620-03-1-0256]
We perform electrical transport measurements in graphene with several sample geometries. In particular, we design invasive probes crossing the whole graphene sheet as well as external probes connected through graphene side arms. The four-probe conductance measured between external probes varies linearly with charge density and is symmetric between electron and hole types of carriers. In contrast measurements with invasive probes give a strong electron-hole asymmetry and a sublinear conductance as a function of density. By comparing various geometries and types of contact metal, we show that these two observations are due to transport properties of the metal/graphene interface. The asymmetry originates from the pinning of the charge density below the metal, which thereby forms a p-n or p-p junction, depending on the polarity of the carriers in the bulk graphene sheet. Our results also explain part of the sublinearity observed in conductance as a function of density in a large number of experiments on graphene, which has generally been attributed to short-range scattering only.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据