C_（60）的制备及其掺银薄膜的结构分析
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摘要
C_(60)薄膜作为新的半导体材料具备许多优越特性，如禁带宽度大、直接带隙、快速响应时间、高的光学损伤阀值、较宽的响应频带等，这些性能预示了C_(60)薄膜在计算机、集成光学器件、光存储器等方面具有广阔的应用前景，但C_(60)材料的制备与提纯还一直是阻碍该新材料投入大规模实际应用的主要因素。对于Ag掺杂C_(60)材料，相关研究很少。但同碱金属元素和铜元素一样，Ag原子的最外层电子都只有一个，而且从多方面的比较而言，Ag元素和Cu元素有着很多的相似之处。这说明同碱金属或铜掺杂材料一样，Ag掺杂的C_(60)薄膜也将有很多的研究价值，在光电材料等方面极有可能具有许多尚未人知的优点。因此本实验选择Ag作为掺杂物质进行探索性研究，对其薄膜在不同实验条件下的结构作了仔细分析，为日后深入研究奠定了实验基础。
本文首先研究了氦气分压、弧电流大小、电极间距以及电极推进速度等实验条件对制备C_(60)粗品产率的影响；接着选用柱色谱法分离提纯得到了纯度大于99.9％的C_(60)固体，比较了不同流动相和固定相的提纯效率和效果；然后采用自己改进后的真空镀膜机，利用电阻式加热蒸镀方法，得到了纯C_(60)薄膜和不同掺杂比的银掺杂薄膜；探讨了沉积速率、衬底种类、衬底表面结构以及衬底温度等实验条件对薄膜结构的影响；最后通过XPS，AFM，紫外，红外，拉曼对薄膜的成分、结构和特性作了定性和半定量分析。
研究表明：
1．在尽可能快的推进石墨棒的条件下，弧电流300A、氦气压150torr、无氦气流时C_(60)粗品的产率最高，约为15％；
2．柱色谱法提纯C_(60)采用环己烷作为流动相比通常采用的正己烷效率更高(固定相为三氧化二铝和活性碳的混合物)；
3．相对较弱的表面作用，低沉积速率和高衬底温度可使纯C_(60)薄膜生长更加有序；
4．衬底温度在不同区间对掺杂薄膜粗糙度的影响不同，在低温区(低于
40摄氏度)温度升高粗糙度降低;而高温区(高于40摄氏度)反之。本文对
银掺杂C60薄膜的粗糙化机理作了理论解释;
5.测量得到了不同的银掺杂比率下薄膜的紫外一可见光谱、红外光谱和
拉曼散射光谱，通过对比理论计算和文献中的实验测试值，验证了我们改进后
的C6。制备和提纯工艺是可靠而且高效的;根据对掺杂薄膜紫外谱线的特征峰
红移现象的仔细分析，确定了低掺杂薄膜C6。分子接收了一个电子而以c汾的
状态存在;红外光谱和拉曼光谱的测试分析数据为日后深入研究银掺杂薄膜的
微观结构形态以及理论计算提供了可贵的实验数据，比如银原子的填入引起了
C6。分子怎样的变形，而降低的对称性又使哪些红外或拉曼沉寂模式得以激活，
再如对掺杂薄膜作得xRD分析后，可以利用拉曼光谱做出掺杂薄膜应变层的
应力分析等等，由于时间和经费的限制，这些工作将在以后的研究中继续。
C60, a new type of semiconductor material, has many superior properties, such as wide forbidden band, direct band gap, rapid responding time, high optical damage threshold value and wide responding frequency band etc. These capabilities indicate that C60 film will be used widely in computer, integrate optical instrument and storage device etc. However, the preparation and the purification of C60 material affect the large-scale application at all times. Although there are few correlative studies on silver-doped films, the same as copper-doped films, there are a lot of scientific values for silver-doped films. So we choose it and make analysis of its structure under the different experimental conditions.
This paper presents the effects of some features on the productivity of raw C60 materials, such as distance and approaching speed of electrodes, helium partial pressure and arc current etc. Then we separate and purify the raw materials and obtain pure solid C60 of 99. 9% and compare the purification efficiency and effect of different fluxion phase and fixed phase and discuss the effects of the experimental conditions, such as the depositing speed, the type of the substrate, the surface structure of the substrate and the temperature of the substrate. Finally, we use XPS, AFM, ultraviolet, infrared and Raman to analyze the component, structure and feature of the films qualitatively and quantitatively. Our study indicates:
1. A production rate as high as 15% is obtained under the condition of 150torr helium partial pressure, 300A arc current and quick electrode approaching speed as soon as possible.
2. With weak surface interaction of substrate, low deposition velocity and high substrate temperature can make pure C60 films generate more orderly.
3. The substrate temperature affects roughness degree differently in different regions. In the region of low temperature( lower than 40℃,when the temperature increases, the roughness degree decreases, however in the region of high temperature( higher than 40℃),the case is reversed.
4. After having made a survey of ultraviolet spectrum, infrared spectrum and Raman scattering spectrum at different silver-doped rate and compared the theoretical compute with the experimental values in references, we confirm that our new method of the preparation and purification of C60 is reliable and efficient. The testing and analysis data of infrared spectrum and Raman spectrum provide valuable experimental data for thorough study of the microcosmic structure of silver-doped films and theoretical in the future.
本文首先研究了氦气分压、弧电流大小、电极间距以及电极推进速度等实验条件对制备C_(60)粗品产率的影响；接着选用柱色谱法分离提纯得到了纯度大于99.9％的C_(60)固体，比较了不同流动相和固定相的提纯效率和效果；然后采用自己改进后的真空镀膜机，利用电阻式加热蒸镀方法，得到了纯C_(60)薄膜和不同掺杂比的银掺杂薄膜；探讨了沉积速率、衬底种类、衬底表面结构以及衬底温度等实验条件对薄膜结构的影响；最后通过XPS，AFM，紫外，红外，拉曼对薄膜的成分、结构和特性作了定性和半定量分析。
研究表明：
1．在尽可能快的推进石墨棒的条件下，弧电流300A、氦气压150torr、无氦气流时C_(60)粗品的产率最高，约为15％；
2．柱色谱法提纯C_(60)采用环己烷作为流动相比通常采用的正己烷效率更高(固定相为三氧化二铝和活性碳的混合物)；
3．相对较弱的表面作用，低沉积速率和高衬底温度可使纯C_(60)薄膜生长更加有序；
4．衬底温度在不同区间对掺杂薄膜粗糙度的影响不同，在低温区(低于
40摄氏度)温度升高粗糙度降低;而高温区(高于40摄氏度)反之。本文对
银掺杂C60薄膜的粗糙化机理作了理论解释;
5.测量得到了不同的银掺杂比率下薄膜的紫外一可见光谱、红外光谱和
拉曼散射光谱，通过对比理论计算和文献中的实验测试值，验证了我们改进后
的C6。制备和提纯工艺是可靠而且高效的;根据对掺杂薄膜紫外谱线的特征峰
红移现象的仔细分析，确定了低掺杂薄膜C6。分子接收了一个电子而以c汾的
状态存在;红外光谱和拉曼光谱的测试分析数据为日后深入研究银掺杂薄膜的
微观结构形态以及理论计算提供了可贵的实验数据，比如银原子的填入引起了
C6。分子怎样的变形，而降低的对称性又使哪些红外或拉曼沉寂模式得以激活，
再如对掺杂薄膜作得xRD分析后，可以利用拉曼光谱做出掺杂薄膜应变层的
应力分析等等，由于时间和经费的限制，这些工作将在以后的研究中继续。
C60, a new type of semiconductor material, has many superior properties, such as wide forbidden band, direct band gap, rapid responding time, high optical damage threshold value and wide responding frequency band etc. These capabilities indicate that C60 film will be used widely in computer, integrate optical instrument and storage device etc. However, the preparation and the purification of C60 material affect the large-scale application at all times. Although there are few correlative studies on silver-doped films, the same as copper-doped films, there are a lot of scientific values for silver-doped films. So we choose it and make analysis of its structure under the different experimental conditions.
This paper presents the effects of some features on the productivity of raw C60 materials, such as distance and approaching speed of electrodes, helium partial pressure and arc current etc. Then we separate and purify the raw materials and obtain pure solid C60 of 99. 9% and compare the purification efficiency and effect of different fluxion phase and fixed phase and discuss the effects of the experimental conditions, such as the depositing speed, the type of the substrate, the surface structure of the substrate and the temperature of the substrate. Finally, we use XPS, AFM, ultraviolet, infrared and Raman to analyze the component, structure and feature of the films qualitatively and quantitatively. Our study indicates:
1. A production rate as high as 15% is obtained under the condition of 150torr helium partial pressure, 300A arc current and quick electrode approaching speed as soon as possible.
2. With weak surface interaction of substrate, low deposition velocity and high substrate temperature can make pure C60 films generate more orderly.
3. The substrate temperature affects roughness degree differently in different regions. In the region of low temperature( lower than 40℃,when the temperature increases, the roughness degree decreases, however in the region of high temperature( higher than 40℃),the case is reversed.
4. After having made a survey of ultraviolet spectrum, infrared spectrum and Raman scattering spectrum at different silver-doped rate and compared the theoretical compute with the experimental values in references, we confirm that our new method of the preparation and purification of C60 is reliable and efficient. The testing and analysis data of infrared spectrum and Raman spectrum provide valuable experimental data for thorough study of the microcosmic structure of silver-doped films and theoretical in the future.
引文
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[42] 邱介山，周红艺等．大连理工大学学报，第38卷第1期(1998)．
[43] 黄春辉，甘良兵等．科学通报，1994，39．(14)：1283．
[44] J.L.Atvood, G.A.Koutsantonls and C.L.Raston.Nature, 368(1994)229.
[45] 郭军等．科学通报，37(1992)1773．
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[48] 巩金龙等．科学通报，40(1995)2134．
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[50] Y.Z.Li, et al. Science, 252(1991)547.
[51] Ayyakkannu MANIVANNA, et al. Jpa.J.Appl.Phys.,31(1992)3680.
[52] 吴卫东等．材料导报．11(1996)6．
[53] Qikun Xue, et al. Thin Solid Film, 281-282(1996)618.
[54] Yuji Yoshida. Thin Solid Film, 281-282(1996)80.
[55] Kaimin Chen, et al. J. Am. Chem. Soc., 115(1993)1193.
[56] D.Stifter and H.sitter. Appl. Phys. Lett., 66(1995)679.
[57] Mactepob B. φ., et al. φTT, 37(1995)2530.
[58] Wenzheng Tang and A.R.Bishop. Phys Reviev., B, 1994,50(7):5016.
[59] 腾启文等．化学学报，1995，53：105．
[2] R.A.Davidson, Ther.Chim.Acta., 193-195(1981)58.
[3] E.A.Rohlfing, D.M.Cox, A.J.Kaidor, Chem.Phys., 81(1984)3322.
[4] H.W.Kroto, et al. Nature, 318(1985)162.
[5] W.Kratschmer, LambLD, Fostiropoulos K., Solid C60: a new form of carbon., Nature, 1990, 347: 354
[6] 李玉增，富勒烯及其金属掺杂材料的研究与应用，稀有金属，第22卷 第2期
[7] S.Iijima, Nature, 354(1991) 56.
[8] P.M.Ajayan, et al. Chem. Phys. Lett., 202(1993)384.
[9] M.S.Dresselhaus, et al. Phys. Rev. B, 45(1992)6234
[10] R. Ettl, et al. Nature, 353(1991)149.
[11] A.S.Koch, et al. J.Org.Chem, 56(1991)4543.
[12] K.Kikuchi, et al. Nature, 357(1992)142
[13] O.Ugarte, Nature, 359(1992)707.
[14] R.C.Haddon, et al. Chem.Phys.Lett., 125(1986)459.
[15] M.Ozaki, et al. Chem.Phys.Lett., 127(1986)242.
[16] M.O.Newton, et al. J.Am.Chem.Soc., 108(1986)2469.
[17] D.S.Marynick, et al. Chem.Phys.Lett., 132(1986)383.
[18] K.Hedberg, et al. Science, 254(1991)410.
[19] C.S.Yannoni, et al. J.Am.Chem.Soc., 113(1991)3190.
[20] J.M.Hawkins, et al. Science, 252(1992)312.
[21] W.I.F.David, et al. Nature, 353(1991)147.
[22] Macro Haser, et al. Chem.Phys.Lett., 181(1991)497.
[23] A.K.Sopert, et al. J Phys.Condens, Matter., 4(1991)147
[24] S.Liu, et al. Science, 245(1991)410.
[25] 周维亚 等，科学通报，39(1994)1667．
[26] O'Keefe, et al. Chem.Phys.Lett., 130(1986)17.
[27] N.Hamada, et al. Phys.Rev.Lett., 68(1992)1579.
[28] M.N.Regueiro, et al. Nature, 355(1992)237.
[29] H.S.Chen, et al. J.Phys,Chem.,96(1992)1016.
[30] Dirk Porezag and Mark R.Pederson, Phys.Rev.B, 52(1995)14963.
[31] Amos B Smith, et al. J.Am.Chem.Soc.117(1995)9359.
[32] P.Pradel, et al. Chem.Phys.lett.,158(1989)412.
[33] W.A.Scrivens, et al. J.Org.Chem, 57(1992)6932.
[34] J.B.Howand, et al.Nature,352(1991)139.
[35] R.E.Smalley, ACC.Chem.Rev., 325(1992)98.
[36] G.Brinkmalm, et al. Phys.Rev.B, 47(1993)7560.
[37] R.E.Smalley, et al. J.Phys.Chem., 96(1993)8696.
[38] L.D.Lamb and D.R.Huffman, J.Phys. Chem.Solids., 54(1993)1635.
[39] R.S.Ruoff, et al. J.Phys.Chem., 97(1993)3379.
[40] 张宝，李新海等，分析测试学报：色谱法分离富勒烯的研究．第17卷第1期(1998)
[41] Bethune D S, Meijer G, Tong W C, et al. The vibrational Raman an spectra of purified solid films of C_(60) and C_(70). Chem.Phys Lett, 1990, 174:219
[42] 邱介山，周红艺等．大连理工大学学报，第38卷第1期(1998)．
[43] 黄春辉，甘良兵等．科学通报，1994，39．(14)：1283．
[44] J.L.Atvood, G.A.Koutsantonls and C.L.Raston.Nature, 368(1994)229.
[45] 郭军等．科学通报，37(1992)1773．
[46] Jerzy Chlistunoff, et al. Thin Solid Film, 257(1995)166.
[47] Wonyong Koh, et al. J.Phys.Chem., 96(1992)4163.
[48] 巩金龙等．科学通报，40(1995)2134．
[49] A.F.Hebard, et al. Appl.Phys.Lett., 59(1991)2109.
[50] Y.Z.Li, et al. Science, 252(1991)547.
[51] Ayyakkannu MANIVANNA, et al. Jpa.J.Appl.Phys.,31(1992)3680.
[52] 吴卫东等．材料导报．11(1996)6．
[53] Qikun Xue, et al. Thin Solid Film, 281-282(1996)618.
[54] Yuji Yoshida. Thin Solid Film, 281-282(1996)80.
[55] Kaimin Chen, et al. J. Am. Chem. Soc., 115(1993)1193.
[56] D.Stifter and H.sitter. Appl. Phys. Lett., 66(1995)679.
[57] Mactepob B. φ., et al. φTT, 37(1995)2530.
[58] Wenzheng Tang and A.R.Bishop. Phys Reviev., B, 1994,50(7):5016.
[59] 腾启文等．化学学报，1995，53：105．