The characterization of grephene 班级：09级材料三班组员：朱杉（编辑校稿） 张强（文章撰写） 高厚仁（资料收集） 陈宏翔（文章撰写） 开赛尔江（其他）石墨烯的表征方法石墨烯的表征方法石墨烯的表征方法石墨烯的表征方法1 Introduction Graphene a two-dimensional, single-layer sheet of sp2-hybridized carbon atoms, has attracted tremendous attention and research interest, owing to its exceptional physical properties.1.1 Synthesis of grapheneMechanical exfoliationChemical vapor deposition (CVD)Chemically derived grapheneOther synthesis approaches2 Morphology analysisAtom Force Microscope （AFM）Scanning Tunnel Microscope （STM）Scanning Electron Microscope（SEM）Optical Microscope （OM）2.1 AFMPreparationObservationPerformance testFig1. SEM images of early attempts at mechanical exfoliation using graphite pillarsFig2. 3D model of AFM tip/specimen contactFig3. Mechanical exfoliation produced the very first single layer graphene flakes. Fig4.(a) 8 m x8 m AFM topography (b) Pseudo-3D representationFig5. Schematic of AFM tip/specimen contact under negative and positive appliedloads.Fig6.Fig7 . AFM image of the graphene specimen, 2D profiles at the six different regions and the thickness at the six sites indicated on the imageFig8. AFM images of graphene specimen (a) before and (b) after wear test.Fig9. (a) AFM image of wear tracks and (b) the cross-sections of wear tracks.2 Morphology analysisAtom Force Microscope （AFM）Scanning Tunnel Microscope （STM）Scanning Electron Microscope（SEM）Optical Microscope （OM）2.2 STMFig10. (a) STM image of graphite showing only the three carbons that eclipse a neighbor in the sheet directly below. (b) In contrast,all six carbons are equivalent and thus visible in mechanically exfoliated single-layer graphene. 2 Morphology analysisAtom Force Microscope （AFM）Scanning Tunnel Microscope （STM）Scanning Electron Microscope（SEM）Optical Microscope （OM）Fig11.Graphene nanofabric. SEM micrograph of a strongly crumpled graphene sheet on a Si wafer. Note that it looks just like silk thrown over a surface. Lateral size of the image is 20 microns. Si wafer is at the bottom-right corner.2.3 SEMFig12.(a)(b)SEM image of graphene1 Morphology analysisAtom Force Microscope （AFM）Scanning Tunnel Microscope （STM）Scanning Electron Microscope（SEM）Optical Microscope （OM）2.4 OMFigure 13. The interference pattern we calculate can be convertedinto RGB colors (a) and the comparison with the experimentally observed colors (b) is good. The red (c), green (d), and blue (e) components from the same image reproduce the main features of our numerical result in Figure 2b. While image (b) was not modifiedin any way, contrast on panels c, d, and e was maximized for better visibility. (f) Large-scale atomic force scan for thickness reference.Figure 14. Image of big graphite flake containing regions of many different thicknesses. A ultrathin graphite region (thickness below 2nm) is highlighted by a dashed rectangle. (a)OM;(b)AFM;(c)SEMFig15. Optical reflection and transmission schematic for a layered thin-film system consisting of a dielectric film (Al2O3, SiO2,or Si3N4) on silicon wafer (left part) and graphene added on the dielectric film (right part).3 Phase analysisX-Ray Diffraction（XRD）Transmission Electron Microscope （TEM）2.1 XRDFig17.XRD patterns of graphite(a)、graphiteoxide(b)and graphene(c)Fig18. XRD patterns of (a) before the CVD growth and (b) after the CVD growth of graphene multi-layers. Open circles: graphen multi-layers,open square: Fe, solid circles: Fe3C3 Phase analysisX-Ray Diffraction（XRD）Transmission Electron Microscope （TEM）Fig 19 (a)TEM images to show an example of a graphene.Fig20.The relative SAED pattern of the graphene sample 3.2 TEMFig21a,b) High-resolution TEM images d,e) Electron diffraction patterns taken from the positions of the d) black and e) white500nm500nmFig 22 (a)TEM images and SAED pattern together to show an example of a graphene grain. (b)Bright field TEM image of two coalesced grains and SAED. The SAED patterns have been filtered Fig23.TEM image and SAED pattern of the GNS film (a, b). TEM imageand SAED pattern of the a-CNP/GNS composite film (c, d)4 ConclusionWith new access to 2D crystallites, experimentalists scrambled to confirm results long predicted by theory. Before they could do so, techniques needed to be developed for the characterization of deposited flakes.In light of such collaborations, it is difficult to believe that the future for graphene is anything but bright.Thank youThank youThank youThank you. . . .