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arXiv 0901.1136cond-mat.mtrl-scicond-mat.mes-hall
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Ni基大尺寸石墨薄膜的合成及其绝缘体化:结构和电学性质

Large-scale Graphitic Thin Films Synthesized on Ni and Transferred to Insulators: Structural and Electronic Properties

Helin Cao, Qingkai Yu, Robert Colby, Deepak Pandey, C. S. Park, Jie Lian, Dmitry Zemlyanov, Isaac Childres, Vladimir Drachev, Eric A. Stach, Muhammad Hussain, H… 展开作者

Helin Cao, Qingkai Yu, Robert Colby, Deepak Pandey, C. S. Park, Jie Lian, Dmitry Zemlyanov, Isaac Childres, Vladimir Drachev, Eric A. Stach, Muhammad Hussain, Hao Li, Steven S. Pei, Yong P. Chen

摘要:

我们提出了一个全面的研究的结构和电子性质的石墨烯层的石墨烯薄膜的合成化学气相沉积(CVD)的基础上的表面偏析多晶镍箔,然后转移到绝缘SiO2/Si衬底。已经合成了尺寸高达几毫米的膜。通过原子力显微镜(AFM)、扫描隧道显微镜(STM)、横截面透射电子显微镜(XTEM)和拉曼光谱的结构表征证实,这种大尺度石墨薄膜(GTF)包含厚石墨区域和少层石墨烯的薄区域。薄膜也包含许多皱纹,尖锐弯曲的尖端和位错揭示了XTEM,产生的增长和屈曲过程的GTF的见解。对由转移的GTF制备的mm级背栅晶体管器件的测量显示了双极场效应,其电阻调制约为50%,载流子迁移率达到约2000 cm^2/Vs。我们还从低温磁输运测量中的二维弱局域化观察到了相位相干长度超过0.2 $μ$ m的载流子量子输运。我们的研究结果表明,尽管不均匀性和表面粗糙度,这种大规模的,灵活的薄膜可以有电子性能的设备应用前景。

英文摘要:

We present a comprehensive study of the structural and electronic properties of ultrathin films containing graphene layers synthesized by chemical vapor deposition (CVD) based surface segregation on polycrystalline Ni foils then transferred onto insulating SiO2/Si substrates. Films of size up to several mm's have been synthesized. Structural characterizations by atomic force microscopy (AFM), scanning tunneling microscopy (STM), cross-sectional transmission electron microscopy (XTEM) and Raman spectroscopy confirm that such large scale graphitic thin films (GTF) contain both thick graphite regions and thin regions of few layer graphene. The films also contain many wrinkles, with sharply-bent tips and dislocations revealed by XTEM, yielding insights on the growth and buckling processes of the GTF. Measurements on mm-scale back-gated transistor devices fabricated from the transferred GTF show ambipolar field effect with resistance modulation ~50% and carrier mobilities reaching ~2000 cm^2/Vs. We also demonstrate quantum transport of carriers with phase coherence length over 0.2 $μ$m from the observation of 2D weak localization in low temperature magneto-transport measurements. Our results show that despite the non-uniformity and surface roughness, such large-scale, flexible thin films can have electronic properties promising for device applications.

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。

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