本研究在探討有限長度加蓋型單層奈米碳管在氧原子化學吸附後，其結構與電性的變化，結構最佳化方法是用半經驗法 (AM1)，單點能量計算使用的是DFT (B3LYP/4-31G)，碳管模型含括各類型碳管：(5，5)、(6，4)、(7，3)、(8，1)、(9，0)、(6，6)、(6，5)、(7，4)、(7，5)、(8，3)、(8，4)、(9，2)、(10，0)。研究顯示氧原子的吸附皆會造成吸附位置上的碳碳鍵拉長，依其構形變化輕重可分為兩區：劇烈形變區 (sin2θ > 0.5)及輕微形變區 (sin2θ < 0.5)，劇烈形變區氧原子吸附之碳碳鍵劇烈拉長，拉長約50%，使得碳管構形大幅改變，而輕微形變區構形變化較不明顯。且在劇烈形變區碳管總能量下降較多 (200~450 kJ mol-1)，比輕微形變區多出約100~200 kJ mol-1。而在DOS計算結果中發現，在劇烈形變區，氧原子對碳管的導電性影響不大；而在輕微形變區，氧原子對碳管導電性影響較大，但有使碳管導電度變好，也有使其導電度變差的例子。由於氧原子較易吸附於劇烈形變區，而不是輕微形變區，因此推測氧原子吸附可能不是導致碳管導電性變佳的主要原因。

　In the present work, theoretical study utlizing DFT and AM1 method to calculate single point energies and structure optimizations of capped finite length single-walled carbon nanotubes (SWCNTs), respectively, including (5,5), (6,4), (7,3), (8,1), (9,0), (10, 0), (9, 2), (8, 4), (8, 3), (7, 5), (7, 4), (6, 5), and (6, 6), chemisorbed by an oxygen atom were carried out by means of GAUSSIAN suite of programs. It reveals that the C-C bond adsorbed by an oxygen atom elongates universally. Based on the extent of elongation of the C-C bond on the SWCNT adsorbed chemically by an oxygen atom, it can be devided as two areas: DA, drastic-alteration area (sin2θ > 0.5) and SA, slight-alteration area (sin2θ < 0.5). In DA area, adsorption energies are much higher than those in other angle range; in other words, that is, DA is more stable than SA. According to DOS data, the conductivity of SWCNTs in DA is almost equivalent to that before adsorption and that of SWCNTs in SA changes significantly. Consequently, due to the oxygen atom adsorption is more stable in DA than in SA, it is reasonable to conjecture that oxygenation is not the main cause to ameliorate the conductance of SWCNTs.

1. S. Iijima, T. Ichihashi; Nature 354, 56, (1991)
2. S. Iijima, T. Ichihashi; Nature 363, 603, (1993)
3. D.S. Bethune, C.H. Kiang, M.S. Devries; Nature 363, 605, (1993)
4. A.C. Dillon, K.M. Jones, T.A. Bekkedahl, C.H. Kiang, D.S. Bethune, M.J. Heben; Nature 386, 377, (1997)
5. P. Chen, X. Wu, J. Lin, K.L. Tan; Science 285, 91, (1999)
6. Y. Chen, D. T. Shaw, X. D. Bai, E.G. Wang, C. Lund, W.M. Lu, D.D.L. Chung; Appl. Phys. Lett. 78, 2128, (2001)
7. H. Shimoda, B. Gao, X.P. Tang, A. Kleinhammes, L. Fleming, Y. Wu, O. Zhou; Phys. Rev. Lett. 88, 015502, (2002)
8. G.T.W. Wu, C.S. Wang, X.B. Zhang, H.S. Yang, Z. F. Qi, P.M. He, W.Z. Lia; J. Electrochem. Soc. 146, 1696, (1999)
9. J.Kong, N.R. franklin, C. Zhou, et al.; Science 287, 622, (2000)
10. P.G. Collins, K. Bradley, M. Ishigami, A. Zettl; Science 287, 1801, (2000)
11. Y.J. Lu, J. Li, J. Han, H.T. Ng, Ch. Binder, Ch. Partridge, M. Meyyappan; Chem. Phys. Lett. 391, 344, (2004)
12. A. Kolmakov, M. Moskovits; Annu. Rev. Mater. Res. 34, 151, (2004)
13. Z.L. Li, P. Dharap, S. Nagarajaiah, E.V. Barrera, J.D. Kim; Adv. Mater. 16, 740, (2004)
14. M.S. Dresselhaus, G. Dresselhaus, P.C. Eklund; Science of fullerenes and carbon nanotubes, Academic Press, New York, 1996.
15. M. Ouyang, J. L. Huang, Ch. Li Cheung, Ch.M. Lieber; Science 292, 702, (2001)
16. J. Cioslowski, N. Rao, D. Moncrieff; J. Am. Chem. Soc. 124, 8485, (2002)
17. K. Bradley, S.H. Jhi, P.G. Collins, J. Hone, M.L. Cohen, S.G. Louie, A. Zettl; Phys. Rev. Lett. 85, 4361, (2000)
18. X.Y. Zhu, S.M. Lee, Y.H. Lee, T. Frauenheim; Phys. Rev. Lett. 85, 2757, (2000)
19. S.H. Jhi, S.G. Louie, M.L. Cohen; Phys. Rev. Lett. 85, 1710, (2000)
20. D.C. Sorescu, K.D. Jordan, Ph. Avouris; J. Phys. Chem. B 105, 11227, (2001)
21. D.J. Mann, M.D. Halls; J. Chem. Phys. 116, 9014, (2002)
22. P. Giannozzi, R. Car, G. Scoles; J. Chem. Phys. 118, 1003, (2003)
23. G.E. Froudakis, M. Schnell, M. Muhlhauser, S.D. Peyerimhoff, A.N. Andriotis, M. Menon, R.M. Sheetz; Phys. Rev. B 68, 115435, (2003)
24. S. Dag, O. Gülseren, O.; S. Ciraci; Chem. Phys. Lett. 380, 1, (2003)
25. S.P. Chan, G. Chen, X.G. Gong, Z.F. Liu; Phys. Rev. Lett. 90, 086403-1, (2003)
26. V. Barone, J. Heyd, G.E. Scuseria; Chem. Phys. Lett. 389, 289, (2004)
27. S. Dag, et al.; Phys. Rev. B 67, 165424, (2003)
28. X. Blase, L.X. Benedict, E.L. Shirley, S.G. Louie; Phys. Rev. Lett. 72, 1878, (1994)
29. J.W. Che, T. Cagın, W.A. Goddard III; Nanotech. 11, 65, (2000)
30. 成會明；奈米碳管, 五南出版社, 台北, 2004
31. T.W. Odom, J.L. Huang, Ph. Kim, Ch.M. Lieber; J. Phys. Chem. B 104, 2794 (2000)
32. R.F. Service; Science 281, 940 (1998)
33. J.H. Hafner, C.L. Cheung, C.M. Lieber; Nature 398, 761, (1999)
34. H.J. Dai, J.H. Hafner, A.G. Rinzler, D.T. COLBERT, R.E. Smalley; Nature 384, 147, (1996)
35. T.W. Odom, J.H. Hafner, C.M. Lieber, in: M.S. Dresselhaus, G. Dresselhaus, Ph. Avouris; Carbon Nanotubes, Springer, New York , 173, 2001
36. W.B. Choi, D.S. Chung, J.H. Kang, H.Y. Kim, Y.W. Jin, I.T. Han, Y.H. Lee, J.E. Jung, N.S. Lee, G.S. Park, J.M. Kim; Appl. Phys. Lett. 75, 3129, (1999)
37. Y. Chen, D.T. Shaw, L.P. Guo; Appl. Phys. Lett. 76, 2469, (2000)
38. H. Jung, D.J. Lee, H.T. Chun; MATERIALS SCIENCE FORUM Part 1-5 (2005) 475-479: 1889-1892
39. P.M. Ajayan, S. Iijima; Nature 361, 333, (1993)
40. S. Seraphin, D. Zhou, J.C. Withers, R. LOUTFY; Nature 362, 503, (1993)
41. S.C. Tsang, Y. K. Chen, P.J.F. Harris, M.L.H. GREEN; Nature 372, 159, (1994)
42. E. Dujardin, T.W. Ebbesen, H. Hiura, K. Tanigaki; Science 265, 1850, (1994)
43. P.G. Collins, M. S. Arnold, Ph. Avouris; Science 292, 706, (2001)
44. S.J. Tans, A.R. Verschueren, C. Dekker; Nature 393, 49, (1998)
45. V. Deryke, R. Martel, T. Appenzeller, Ph. Avouris; Nano Lett. 1, 453, (2001)
46. A. Bachtold, P. Hadley, T. Nakanishi, C. Dekker; Science 294, 1317, (2001)
47. Y.J. Lu, J. Li, J. Han, H.T. Ng, C. Binder, Ch. Partridge, M. Meyyappan; Chem. Phys. Lett. 391, 344, (2004)
48. K. Yamamoto, G. Shi, T.S. Zhou, F. Xu, J. Xu, T. Kato, J.Y Jind L. Jin; Analyst 128, 249, (2003)
49. G. Che, B.B. Lakshmi, E.R. Fisher, Ch.R. Martin; Nature 393, 346, (1998)
50. M. Fujita, R. Saito, G. Dresselhaus, M.S. Dresselhaus; Phys. Rev. B 45, 13834, (1992)
51. A. Rochefort, D.R. Salahub, Ph. Avouris; J. Phys. Chem. B 103, 641, (1999)
52. M. Dewar, W. Thiel; J. Am. Chem. Soc. 99, 4499, (1977)
53. P. Hohenberg, W. Kohn; Phys. Rev. 136, B864, (1964)
54. W. Kohn, L. J. Sham; Phys. Rev. 140, A1133, (1965)
55. A.D. Becke; Phys. Rev. A 38, 3098, (1988)
56. C. Lee, W. Yang, R.G. Parr; Phys. Rev. B 37, 785, (1988)
57. A. Ricca, Ch. W. Bauschlicher Jr.; Phys. Rev. B 68, 035433, (2003)
58. G. Sun, J. Kurti, M. Kertesz, R.H. Baughman; J. Phys. Chem. B 107, 6924, (2003)
59. S.M. Bachilo, M.S. Strano, C. Kittrell, R.H. Hauge,. R.E. Smalley, R.B. Weisman; Science 298, 2361, (2002)