Four-Terminal Magneto-Transport in Graphene p-n Junctions Created by Spatially Selective Doping
详细信息 查看全文
- 作者：Timm Lohmann ; Klaus von Klitzing ; Jurgen H. Smet
- 刊名：Nano Letters
- 出版年：2009
- 出版时间：May 13, 2009
- 年：2009
- 卷：9
- 期：5
- 页码：1973-1979
- 全文大小：253K
- 年卷期：v.9,no.5(May 13, 2009)
- ISSN：1530-6992
文摘
In this paper, we describe a graphene p-n junction created by chemical doping. We find that chemical doping does not reduce mobility in contrast to top-gating. The preparation technique has been developed from systematic studies about influences on the initial doping of freshly prepared graphene. We investigated the removal of adsorbates by vacuum treatment, annealing, and compensation doping using NH3. Hysteretic behavior is observed in the electric field effect due to dipolar adsorbates like water and NH3. Finally we demonstrate spatially selective doping of graphene using patterned PMMA. Four-terminal transport measurements of the p-n devices reveal edge channel mixing in the quantum hall regime. Quantized resistances of h/e2, h/3e2 and h/15e2 can be observed as expected from theory.