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
备注:
This version (as published) contains additional data, such as cross sectional TEM images
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.
Electronic Transport in Chemical Vapor Deposited Graphene Synthesized on Cu: Quantum Hall Effect and Weak Localization
我们报告的电子性质的石墨烯合成的化学气相沉积(CVD)铜,然后转移到SiO2/Si。已经合成了晶圆级(高达4英寸)石墨烯膜,如光谱拉曼映射所示,主要由单层石墨烯组成。在由这种CVD石墨烯制造的微型器件上进行低温输运测量,显示双极场效应(开/关比约为5,载流子迁移率高达约3000 cm ^2/Vs)和“半整数”量子霍尔效应,这是单层石墨烯的固有电子性质的标志。我们还观察到弱本地化和提取信息的相位相干性和散射的载波。
Multiproperty Atomistic Characterization of a Synthesized Pyrazinic Nitrogen-Doped Porous Armchair Graphene Nanoribbon
Laboratory of NanoEngineering, College of Technology, University of Brasília(巴西利亚大学技术学院纳米工程实验室);Graduate Program in Physics, Institute of Physics, University of Brasília(巴西利亚大学物理研究所物理研究生项目);Center for Agri-Food Science and Technology, Federal University of Campina Grande(坎皮纳格兰德联邦大学农业食品科学与技术中心);Institute of Physics, Federal University of Rio Grande do Norte(北里奥格兰德联邦大学物理研究所);Department of Applied Physics, Gleb Wataghin Institute of Physics, University of Campinas(坎皮纳斯大学格列布·瓦塔金物理研究所应用物理系);Department of Electrical Engineering, College of Technology, University of Brasília(巴西利亚大学技术学院电气工程系)
A Rapid Thermal Chemical Vapor Deposition System for Fast Synthesis of Epitaxial Graphene Under Ambient Pressure
Tata Institute of Fundamental Research(塔塔基础研究所);The Institute of Science, Homi Bhabha State University(霍米·巴巴赫州立大学理学院);St. Xaviers College(圣泽维尔学院);Indian Institute of Science Education and Research(印度科学教育与研究学院)