Dipartimento di Fisica, Università dell'Aquila, Coppito-L'Aquila, Italy.
Nanotechnology. 2010 Jun 25;21(25):255703. doi: 10.1088/0957-4484/21/25/255703. Epub 2010 Jun 2.
We report a systematic investigation of the colour contrast (CC) of graphene (one, two and three layers) on 50, 72 and 80 nm thick Al(2)O(3)/Si(100) and 100 and 300 nm thick SiO(2)/Si(100). The CC is determined by the analysis of optical microscopy images taken under white light illumination. A corresponding assignment of graphene in the single-layer, double-layer and trilayer phases is made using micro-Raman spectroscopy. A quantitative evaluation allows us to conclude that the colour contrast between 72 nm alumina and graphene is significantly larger than that between 300 nm silicon oxide and graphene (by factors of 2.2, 2.0 and 3.3 for the single-layer, double-layer and trilayer graphene flakes respectively). Moreover, data indicate that, to increase visibility, the use of a red or a green light is preferable.
我们对单层、双层和三层石墨烯在 50、72 和 80nm 厚 Al2O3/Si(100) 和 100nm 和 300nm 厚 SiO2/Si(100) 上的颜色对比度（CC）进行了系统研究。CC 通过白光照明下的光学显微镜图像分析确定。使用微拉曼光谱对石墨烯的相应单层、双层和三层相进行了相应的分配。定量评估使我们能够得出结论，72nm 氧化铝和石墨烯之间的颜色对比度明显大于 300nm 氧化硅和石墨烯之间的颜色对比度（单层、双层和三层石墨烯片分别为 2.2、2.0 和 3.3）。此外，数据表明，为了提高可见度，最好使用红光或绿光。
