常见碳材料及其拉曼光谱

1、常见碳材料及其拉曼光谱陈翠红2008.12.02常见的碳材料有:三维的石墨，金刚石 二维的石墨烯，碳纳米带 一维的碳纳米管，碳纳米线 零维的富勒烯（C6。）建筑学家理查德巴克明斯特富勒 (Richard Buckminster Fuller)设计的美国万国博览馆球形圆顶薄壳建筑。石墨的拉曼光谱HFJ自然界中并不存在宏观尺寸的石墨单晶，而是含有许许 多多任意取向的微小晶粒（lOOum） onrj高定向热解石墨（HOPG）是人工生长的一种石墨，其碳 平面几乎完美地沿其垂直方向堆叠，然而沿着石墨平面 内，晶粒仍然存在任意取向但非常小。(1)结构不同，拉曼光谱不同(2) Gband(1580cmi)是

2、由碳环或长链中的所有sp?原子对的拉伸运动产生的。a)Highly oriented pyrolytic graphite (No D-band) at 1582 cm-1(3)缺陷和无序诱导D-band (-1360cm1)的产生。b)c)Activated Charcoal (D and G bands at 1360,1580cm-1)Amorphous Carbon (a very broad(4) 一般我们用D峰与G峰的强度比来衡量碳材料 的无序度。peak)Raman Spectrum of GraphiteB XUIKSTRA* AND1, K.OKW1GDivisWan oj

3、Af ocroMalecular Science Case W extern Reserve University, CJievclutid, Ohio 4106(Keceived 13 November 1969)IOOOcmJ1575 cnr1At:5N3.LN-GRAPH：T SINGLE CRYSTALTiconderoga FlakeSpectral Sniwidth 2cm-商用石1000500RAMAH $HirT in cm-1Fig. ( Rsuimn icctrum o a single crysul of graphite30201355cnrl峰的出现归结于微晶尺寸效应

4、使得没 有拉曼活性的某些声子在选择定则改变后变得 有了拉曼活性。发现D模对于拉曼活性G模的相对强度与样品中 石墨微晶尺寸的大小相关。10D-band的发现及其研究1970年最先报道了无序诱导的D模。1981年，一些人利用不同的激发光能量研究了石墨的拉曼光谱，得出D 模频率随激发光能量的线性移动。斜率在4050cml/ev之间。1990年，一些人通过实验总结了 D模强度和样品中各种无序或缺陷的相 互关系，证明无论石墨存在任何形式的无序，D模都会出现。无序诱导的D-band的产生一-双共振拉曼散射D,2D-Band-Double ResonanceD-BandG-Band1. e excitati

5、on2. e-phonon scattering3 defect scattering伴随着层数的增加强度提高4. E-hole recombination2D-Bandgraphrie10咻S ayers? hynnc1 hyrr2600 率2800 Raman shift (cnf1)CPAl 一特 UM-匚- 层数依赖性1. e excitation2. e-phonon scattering3 Phonon with opposite momentum260CRarran shift (cm* )2700 2BC0激发光能量依赖性4. E-hole recombination石墨的拉曼

6、光谱roscopy of g;r 11 j N 1 E n E I H 1 A N 13 C I L R L S r I . Z T PL O K I S E 21 Dcicvrt rrt i t o f Ei?/Zzzy/?rity of (C7rzmb rhjei, rJ V-?/rzzy? Zzz(jtrrt St rt? UK(Hr：379OeniQwm.ddk)Irts tit itt fiir Fes t，k OTpci ph 口&z7L; Tcc h /iDi i/沁 ar s i/tdi t 13H(wdunbarjstr.1 0623 I3e/rli.ii.y Crtn,(i

7、:n.ijTizblih.tfrZ cgldm. 14 Sep十emhaT 2(K)4Raman spectroscopy of graphite不同点不同偏振方向的拉曼光谱(a) 完美石墨晶体有缺陷的石墨激发光能量增加，D模频率 向高能方向移动。激发光波长在近红外到近紫外是 线性的，斜率4050cmT/ev2D的大概是D的两倍(a) D模的相对强度与石墨微晶尺寸La的相互关系。(b)石墨一阶和二阶拉曼模的激发光能量依赖性。Figure 7(a) Calculated Rctinra|liene LayersAC. Ferrari JJ.C Meyer,2 V. Scardaci J C. C

8、asi raghi,1 M. Lazzeri/ F. Mauri/ S Piscatiec,1 E). Jiang,-4K. S Zovoglovj S. Roth,2 and A. K Cieim41 Ca/nbrldK University. Enineerinii Department. J J Thompson Avenue Cambridfie CBS O 屁1. United KingdomMct.x P/ajwk Institute ft)r Stolid State Respire h, Sfuftart 705()f CiernutnyIM PMC. Universiids

9、Paris 6 er 7. CNRS. /PGP. 14() rue de Lourmel. 75() 15 Paris. FranceUniiecl4Dcymrnnent t/f Physics cuui Asm/nnmy. Uniferxiiy of Mnnchestef Mcuu hestei M /3 QPL,(Received 9 June 2(X)(S; published 30HSGraphene 中 f心无缺陷存在(a) Comparison of Raman spectra at 514 nm for bulk graphite and graphene. They are

10、scaled to have similar height of the 2D peak at 2700 cm-1.(b) Evolution of the spectra at 514 nm with the number of layers(c) Evolution of the Raman spectra at 633 nm with the number of layers.2500(逊浮心宀严 %10000633 nm50002550 2600 2650 2700 2750 28005U.5 nm15000Raman Shift (cm1)(d) D峰的产生及峰位的不同(e) 2la

11、yer2D峰由四个组成(d) Comparison of the D band at 514 nm at the edge of bulk graphite and single layer graphene. The fit of the D1 and D2 comp orients of the D band of bulk graphite is shown.The four comp orients of the 2D band in 2 layer graphene at 514 and 633 nm.a) Monolayer:q = exchangedphonon momentum

12、xSJauo)TnqFermi leveleL = Laser energyb) Bilayer:rFIG. 3 DR for the 2D peak in (a) single layer and (b) bi layer.Bilayer graphe ne单层及双层graphene2D峰的双共振过程声子支的分裂1.5cm1 所以归因为电子能级的分裂电子能带的分裂， 使bilaye吩裂为四个带APPLIED PHYSICS LETTERS 93, 163112 (2008)Edge chirality determination of graphene by Raman spectrosco

13、pyYuMeng You, ZhenHua Ni, Ting Yu, and ZeXiang Shena,Division of Physics and Applied Physics, School of Physical and Matfiematical Sciences, Nanyang Technological University, Singapore 637371, Singapore(Received 21 July 2008; accepted 30 September 2008; published online 22 October 2008)(a)(c)APPLIED

14、 PHYSICS LETTERS 93, 163112 (2008)30Angle between edgesc m Ar9 6BZ6N4 2 D 8 6 4 11115 30 45 60 75 90 105120135150165Angle (degree)FIG. 1. Color onlinea Optical image of a typical MCG sheet and the angles between edgesb The statistical results of the angle measurements.The standard deviation is 5.4 c

15、 Illustration of the relationship between angles and the chiralities of the adjacent edgesD band intensity6 band intensity(c) 90D band intensityG band intensityD band intensityG band intensity(d)6(r Armchairx厂.pD band IntensityG band intensityFIG. 3. (Color online) Raman imaging results from edges w

16、ith angles (a) 30, (b) 60 (zigzag), (c) 90, and (d) 6*0 (armchair). Tlie images constructed by the G band intensity show the positions and shapes of the SLG sheets. The laser polarization is indicated by the green arrows The super- imposed frameworks are guides for the eye indicating the edge chiral

17、ity. Note that the chirality of (b) and (d) were determined by the other pair of edges (not shown) with 30*790 on the same piece of SLG The scale bar is 1当两相邻边缘的夹角是30。, 90时， 两边缘有不同的手性，一个是armchair, 一个是 zigzag o当夹角是60。时，有相同的手性。无序诱导的D峰的拉曼强度与边缘 手性有关：armchair edge的边缘D峰强度较强, 在zigzag边缘较弱。小结1= Graphene 一般出现

18、三个峰D，G，2D； D和2D峰具有激发光能量依赖性， SLG的2D峰是尖锐的单峰，BLG的2D峰有四个组成，其他的都是两个组 成，可用来区分石墨烯单层与多层。 2D峰起源于动量相反的两个声子参与的双共振拉曼过程。在所有sp2 碳材料中均有发现。石墨烯根据边缘的不同，具有不同的手性，用拉曼光谱，根据Dband 的拉曼强度可以识别graphene edge的手性。 对数百MCG的研究表明，MCG边缘夹角是30的倍数。两相邻边缘的夹角是30 , 90和150。时，两边缘有不同的手性，一 个是armchair,一个是zigzag o当夹角是60 和120。时，有相同的手性。一维碳材料一碳纳米管碳纳米

19、管(Carbon nanotube)是1991年才被发现的一种碳结构。理想纳米碳管是由碳原子形成的石墨烯片层卷成的无缝、中空的管体nm,最小直径大约为0.5 nm,SWNT的直径一般为1 6mn,最小直径大约为0.5 nm,直径大于6nm 以后特别不稳定，会发生SWNT管的塌陷，长度则可达几百纳米到几个微米MWNT的层间距约为0.34纳米，直径在几个纳米到几十纳米，长度一般在微 米量级，最长者可达数毫米碳纳米管中的碳原子以Sp2杂化，但是由于存在一定曲率所以其中也有一小部分碳属Sp3杂化Hundreds of species depend on how it is folded.奇妙的碳纳米管

20、“太空电梯”的绳具有极好的可弯折性4A最细的碳纳米管（0.4 nm）密度小，硬度强，钢的100倍2000年，香港科技大学的汤子康博士即宣布 发现了世界上最细的纯碳纳米碳管0.4nm, 这一结果已达到碳纳米管的理论极限值o碳纳米管的结构沿不同点阵方向卷曲二维石墨烯可形成不同类型的碳纳米管手性矢量Ch = nax+ ma2坷和辺为单位矢量，n，m为整数，手性角8为手性矢量与a】之间的夹角。通常用（n，m）表征碳管结构；也可用直径和螺旋角B表示。dt =Ch/7r = yl3ac_c(rr +nm+m2)2 /zr9 = tan,V3m/(m + 2n)对于不同类型的碳纳米管具有不同的m，n值om=

21、n, 0=30,单臂纳米管。Armchairn或m=0, 0=0 ,锯齿形纳米管。Zigzag B处于0。与30。之间，手性纳米管。chiralarmchair(b)zigzag137375 :metal :semiconductorarmchair(依)24(7872567(7卫34433804X923()903)(b)chiral二维石墨片的卷曲，沿不同点阵方向卷曲可形成不同类型的碳纳米管碳纳米管的性质鳖簇的麟饗蠡鑼手性直径越小电子的状态w美国C.T.White教授计算得出n-m=3q （q为整数），碳管为金属性。其他情况表现半导体性，并且禁带宽度正比于碳管直径的倒数。冬讐纳米管为金属性，

22、锯齿形、手性碳管部分为金属，部分为半导体随着半导体纳米管直径增加，带隙变小，在大直径情况下，带隙为零,呈现金属性质。Structural (n. m) Determination of Isolated Single-Wall Carbon Nanotubesby Resonant Raman ScatteringA. JorioJ R. Saito, J. H. Hafner,6 C. M. Li亡be% M. Hunter? T. McClure,3 G. Dresselbaiis and M. S. Diesselhaus1 *1 Department of Physics, Massa

23、chuselts histintte of Technology, Cambridge, Massachuseils 02/592 De pa rf me nf of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology,Cambridge, Massachusetts 02/39Center for Materials Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139Franci

24、s Bitter Magnet Laboratory. Massachusetts Institute of Technology. Cambridge. Massachusetts 021395Deparrment of Elecrronic-Engineeniig% University of ElectroConmnmicaiog Tokyo. 182-8585 Japan(y Depart meni of Cheniislry, Harvard Uni versify, Camb ridge. A/ ass a ch usetis 02 J 38FIG. I. AFM images o

25、f the sample. The small particles are iron catalysts. The inset shows the diameter distribution of the sample taken from 40 observed SWNTsCVD方法制备的单臂碳纳米管SWNTs的平均直径1.85nm100150200250300350qsueui普通的单个S WNTs的拉曼光谱有三个峰，RBMs D G RBM的频率=A/dt实验测定A=248cm1nm, Si/SiO?上 生长的离散S WNTs比较准确。D峰的频率依赖于激发光能量和直 径。Frequenc

26、y (cnfL)FIG 2. Raman spectra from three different spots on the Si substrate, showing only one resonant nanotube and one RBM frequency for each of 3 spots. The RBM frequencies (widths) and (n,m) assignment for each resonant SWNT are displayed, The 303 cm 1 feature conies from the Si substrate Inset (

27、a) shows Raman spectra from one spot on the sample, including 303, 521, and 963 cm 1 Raman features from the Si substrate. Inset (b) shows a zoom of the corresponding G-band region.碳纳米管的拉曼光谱G-bandfrequency (cm1)A=su3三 U2UC3HGraphite:G峰单一，尖锐 对应q=r=0? mode E2gNanotubes:两个峰G+和起源于 graphite E2gMetallic H

28、 semiconductingG峰的振动模式及其性质1600Qluo) xouenb LL15801560154015201500j 00.20.40.61/dt (1/nm)、CDg、/、亨、metallic / ：/ :semiconductingi 、0.8 1G十：no diameter dependenceT LO axialG diameter dependence 今 TO circumferential160015901580157015601550154015301600159015801570156015501540Semiconducting 一1530倪$.8 1.0

29、1.2 1.4 1.6 1.8 2.0 2.2 2.4Diameter (nm)Metallic tubes:GTL0& G+TTOSemiconducting tubes:G- TTO& G+TLO无序诱导的D-band在SVSiO2衬底上CVD法生长的离散单臂碳纳米管的大量拉曼光谱中，有 一般有强度很弱的D-band号hl”与缺陷石墨D-band相比：较小的线宽7 0,反应电子和声子的量子限 制效应。存在非对称展宽。D谱带频率与直径有关，满足wD=wD+C/dtC对于双共振相关的过程是正的，强化了D普带频率。在弹性常数效应情况 下，wD。就是二维石墨中观察到的频率数值。在实验中还发现扶手椅

30、型与锯齿形的单臂碳纳米管的D普带有24cnri 的频率差。Raman study on double-walled carbon nanotubesJinquan Wei 二 Bin Jiang, Xianfcng Zhang, Hongwei Zhu, Dchai WuDepartment of Mechamcal Engineering. Tsinghua University, Beijing /00084. PR ChinaReceived 13 April 2003： in final form 1 June 2003Published online: 12 JuIy 2003CVD

31、 法， c源：甲烷Length： 10um直径：平均2nmFig. I. Micrograph of the purified DVVNTs. (a) A SEM image of the purified DWNTs. (b) HRTEM image ot a cross-section view of a DWNTs bundle.(a)5001000LL丄15002000D峰半高宽20cm1Raman Shift (em )Fig. 2. (a) Raman spectra of the DWNTs at dillcrcnt Er excitation激发光能量降低最强 RBM的频率提高

32、。原因:内外管相互作用Raman Shift (cmd)3001.58 &V400WRBM=224/d+1 一般9卜管d1.5nm W160cm-1的峰只要 来源于内管直径(b) A close-up view of the RBM of the DWNTs at different Elaser excitation12001250130013501403Raman Shift (cm )(n e) gsuaG一12001250130013501400Raman Shift (cm1)Fig. 3. D-band of the CNTs at diOerent excited /泊“：(a)

33、 圧曲 l .58 eV. (b) 也 l .96 eV and (c)=2.41 cV(n e) esuec-MWNTs(n &) XJ_SUSU-12001260130013501400Raman Shift (cm )CNTs的D-band的频率随激发光 能量的降低而减小相同激发光能量下，DWNTs的D峰频率最低。内外层作用力的影响。Fig. 4. The dependence of the frequency of Dband ol the CNTs on theh Eo) UMS uewpoc线性关系斜率-26.5cm-1/evCNTs:WD=W0+26.5ElaserMWNTs W0=1285DWNTs1260SWNTs1270结论由于内外层相互作用，SWNTs与DWNTs的拉曼光谱不同。L1FJ直径越小，弯曲度越大，兀电子云形状变化越大，相反，直 径越大，弯曲度越小，兀电子云接近石墨的情形，性质接近 石墨。(900c Aujm c ouhuo poqsnqnd 阪乙 iMv t p刃ctegE igoOJ quiooQ 0 poApooy)3odD*H 0O9UI NlodDiqS7 3wq riuuaauiu imusiq aRzoig mvQ