Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Kongens Lyngby, Denmark.
Nanotechnology. 2011 Nov 4;22(44):445702. doi: 10.1088/0957-4484/22/44/445702. Epub 2011 Oct 6.
We present measurements of the electronic properties of graphene using a repositionable micro four-point probe system, which we show here to have unique advantages over measurements made on lithographically defined devices; namely speed, simplicity and lack of a need to pattern graphene. Measurements are performed in ambient, vacuum and controlled environmental conditions using an environmental scanning electron microscope (SEM). The results are comparable to previous results for microcleaved graphene on silicon dioxide (SiO(2)). We observe a pronounced hysteresis of the charge neutrality point, dependent on the sweep rate of the gate voltage; and environmental measurements provide insight into the sensor application prospects of graphene. The method offers a fast, local and non-destructive technique for electronic measurements on graphene, which can be positioned freely on a graphene flake.
我们使用可重新定位的微四点探针系统来测量石墨烯的电子特性，与在光刻定义的器件上进行的测量相比，我们发现该系统具有独特的优势；具体而言，其具有速度快、操作简单以及无需对石墨烯进行图案化处理等优点。在环境扫描电子显微镜（SEM）中，在环境、真空和受控环境条件下进行测量。结果与先前在二氧化硅（SiO2）上进行的微剥离石墨烯的结果相媲美。我们观察到电荷中性点的明显滞后，这取决于栅极电压的扫描速率；环境测量为石墨烯的传感器应用前景提供了深入的了解。该方法为在石墨烯上进行快速、局部和非破坏性的电子测量提供了一种方法，并且可以自由地将其定位在石墨烯薄片上。
