奈米碳管為準一維結構，其載子傳輸具有彈道傳輸（Ballistic Transport）的特性。然而，金屬性奈米碳管在高偏壓下，其電流-電壓特性曲線呈非線性關係，原因在於此時電流的焦耳加熱（Joule Heating）效應使得奈米碳管升溫，電阻因而改變。本研究藉由分析奈米碳管在不同電壓下的拉曼特徵譜線，了解其溫度變化的情形。
在拉曼光譜的量測中，首先為排除雷射可能會改變奈米碳管的溫度，進而影響焦耳加熱實驗，因此改變雷射光的功率來檢測雷射加熱效應對奈米碳管的影響程度。由檢測結果可知，雷射光的加熱效應，對於奈米碳管的G-band之拉曼位移，其影響的位移量在1 cm-1以下，表示雷射對於焦耳加熱實驗之影響可忽略。
在研究焦耳加熱效應的實驗中，分別以置於基板上之單根單壁奈米碳管元件和懸空式單壁奈米碳管元件為研究對象。置於基板上之單根單壁奈米碳管元件的製作方式為在基板上先鍍上電極（材料為鈦與鉑），接著在電極上鍍催化劑（二氧化矽/鎳/二氧化矽），最後以熱裂解化學氣相沉積法（Thermal Chemical Vapor Deposition, Thermal CVD）合成單壁奈米碳管。而懸空式單壁奈米碳管元件，先蝕刻基板以製作溝槽結構，其後製作流程與置於基板上之單根單壁奈米碳管元件相同。此製作方式的好處在於能有效定位奈米碳管。
接著分別對置於基板上之單根單壁奈米碳管元件、懸空式單根單壁奈米碳管元件施加電壓，並臨場量測拉曼光譜，發現置於基板之奈米碳管的G-band之拉曼位移幾乎無任何變化。原因在於G-band的紅移來自於碳管在高溫時，碳-碳（C-C）鍵長增加所導致，而基板的存在將抑制此一現象。而懸空式奈米碳管的G-band之拉曼位移有大幅紅移（拉曼位移向低波數位移）的現象，在1.1 □W的電功率下約有15 cm-1的位移量，在相同的位移量下，小於文獻所發表的電功率。
雖在懸空式奈米碳管元件中，觀測到拉曼位移有紅移的現象，但碳管與基板間電位差所產生之靜電力，可能造成碳管形變，碳-碳鍵因而拉長，造成紅移的原因可能來自於溫度與形變。因此，在外加一閘極電壓的情況下，臨場量測奈米碳管的拉曼譜線，發現此一靜電力對於G-band並無明顯的影響，故懸空式奈米碳管在焦耳加熱的實驗中，可排除形變的影響。

[1] A. K. Geim and K. S. Novoselov, "The rise of graphene," Nat Mater, vol. 6, pp. 183-191, 2007.
[2] S. Iijima, "HELICAL MICROTUBULES OF GRAPHITIC CARBON," Nature, vol. 354, pp. 56-58, Nov 1991.
[3] S. Iijima and T. Ichihashi, "SINGLE-SHELL CARBON NANOTUBES OF 1-NM DIAMETER," Nature, vol. 363, pp. 603-605, Jun 1993.
[4] D. S. Bethune, C. H. Kiang, M. S. Devries, G. Gorman, R. Savoy, J. Vazquez, and R. Beyers, "COBALT-CATALYZED GROWTH OF CARBON NANOTUBES WITH SINGLE-ATOMIC-LAYERWALLS," Nature, vol. 363, pp. 605-607, Jun 1993.
[5] T. W. Ebbesen and P. M. Ajayan, "LARGE-SCALE SYNTHESIS OF CARBON NANOTUBES," Nature, vol. 358, pp. 220-222, Jul 1992.
[6] A. M. Cassell, J. A. Raymakers, J. Kong, and H. J. Dai, "Large scale CVD synthesis of single-walled carbon nanotubes," Journal of Physical Chemistry B, vol. 103, pp. 6484-6492, Aug 1999.
[7] R. E. Smalley, M. S. Dresselhaus, G. Dresselhaus, and P. Avouris, Carbon Nanotubes: Synthesis, Structure, Properties and Applications: Springer, 2001.
[8] S. S. Fan, M. G. Chapline, N. R. Franklin, T. W. Tombler, A. M. Cassell, and H. J. Dai, "Self-oriented regular arrays of carbon nanotubes and their field emission properties," Science, vol. 283, pp. 512-514, Jan 1999.
[9] A. Modi, N. Koratkar, E. Lass, B. Q. Wei, and P. M. Ajayan, "Miniaturized gas ionization sensors using carbon nanotubes," Nature, vol. 424, pp. 171-174, Jul 2003.
[10] S. J. Tans, A. R. M. Verschueren, and C. Dekker, "Room-temperature transistor based on a single carbon nanotube," Nature, vol. 393, pp. 49-52, May 1998.
[11] M. S. Dresselhaus, G. Dresselhaus, A. Jorio, A. G. Souza Filho, and R. Saito, "Raman spectroscopy on isolated single wall carbon nanotubes," Carbon, vol. 40, pp. 2043-2061, 2002.
[12] M. S. Dresselhaus, G. Dresselhaus, R. Saito, and A. Jorio, "Raman spectroscopy of carbon nanotubes," Physics Reports-Review Section of Physics Letters, vol. 409, pp. 47-99, Mar 2005.
[13] T. S. Jespersen, "Raman Scattering in Carbon Nanotubes," MS. Thesis, University of Copenhagen, 2003.
[14] R. Saito, G. Dresselhaus, and M. S. Dresselhaus, Physical properties of carbon nanotubes, 1998.
[15] M. S. Dresselhaus, G. Dresselhaus, and A. Jorio, "Raman spectroscopy of carbon nanotubes in 1997 and 2007," Journal of Physical Chemistry C, vol. 111, pp. 17887-17893, Dec 2007.
[16] Y. Zhang, J. Zhang, H. Son, J. Kong, and Z. Liu, "Substrate-Induced Raman Frequency Variation for Single-Walled Carbon Nanotubes," J. Am. Chem. Soc., vol. 127, pp. 17156-17157, 2005.
[17] A. Jorio, C. Fantini, M. S. S. Dantas, M. A. Pimenta, A. G. Souza, G. G. Samsonidze, V. W. Brar, G. Dresselhaus, M. S. Dresselhaus, A. K. Swan, M. S. Unlu, B. B. Goldberg, and R. Saito, "Linewidth of the Raman features of individual single-wall carbon nanotubes," Physical Review B, vol. 66, Sep 2002.
[18] M. A. P. A. G. S. F. R. S. G. D. A Jorio and M. S. Dresselhaus, "Characterizing carbon nanotube samples with resonance Raman scattering," New Journal of Physics, vol. 5, p. 139, 2003.
[19] E. Pop, D. Mann, J. Cao, Q. Wang, K. Goodson, and H. J. Dai, "Negative differential conductance and hot phonons in suspended nanotube molecular wires," Physical Review Letters, vol. 95, Oct 2005.
[20] E. Pop, D. Mann, J. Reifenberg, K. Goodson, and D. Hongjie, "Electro-thermal transport in metallic single-wall carbon nanotubes for interconnect applications," in Electron Devices Meeting, 2005. IEDM Technical Digest. IEEE International, 2005, p. 4 pp.
[21] E. Pop, D. A. Mann, K. E. Goodson, and H. J. Dai, "Electrical and thermal transport in metallic single-wall carbon nanotubes on insulating substrates," Journal of Applied Physics, vol. 101, May 2007.
[22] M. Lazzeri, S. Piscanec, F. Mauri, A. C. Ferrari, and J. Robertson, "Electron transport and hot phonons in carbon nanotubes," Physical Review Letters, vol. 95, Dec 2005.
[23] H. Lin, "Temperature-dependent Raman features of the individual suspended single-walled carbon nanotubes," MS. Thesis, Nation Tsing Hua University, 2006.
[24] L. J. Ci, Z. P. Zhou, L. Song, X. Q. Yan, D. F. Liu, H. J. Yuan, Y. Gao, J. X. Wang, L. F. Liu, W. Y. Zhou, G. Wang, and S. S. Xie, "Temperature dependence of resonant Raman scattering in double-wall carbon nanotubes," Applied Physics Letters, vol. 82, pp. 3098-3100, May 2003.
[25] A. W. Bushmaker, V. V. Deshpande, M. W. Bockrath, and S. B. Cronin, "Direct observation of mode selective electron-phonon coupling in suspended carbon nanotubes," Nano Letters, vol. 7, pp. 3618-3622, Dec 2007.
[26] M. Oron-Carl and R. Krupke, "Raman spectroscopic evidence for hot-phonon generation in electrically biased carbon nanotubes," Physical Review Letters, vol. 100, Mar 2008.
[27] V. V. Deshpande, S. Hsieh, A. W. Bushmaker, M. Bockrath, and S. B. Cronin, "Spatially Resolved Temperature Measurements of Electrically Heated Carbon Nanotubes," Physical Review Letters, vol. 102, p. 105501, 2009.
[28] Q. Li, C. Liu, X. Wang, and S. Fan, "Measuring the thermal conductivity of individual carbon nanotubes by the Raman shift method," Nanotechnology, vol. 20, p. 145702, 2009.
[29] T. Yano, P. Verma, S. Kawata, and Y. Inouye, "Diameter-selective near-field Raman analysis and imaging of isolated carbon nanotube bundles," Applied Physics Letters, vol. 88, Feb 2006.
[30] N. Anderson, A. Hartschuh, and L. Novotny, "Chirality changes in carbon nanotubes studied with near-field Raman spectroscopy," Nano Letters, vol. 7, pp. 577-582, Mar 2007.
[31] S. S. Kharintsev, G. G. Hoffmann, P. S. Dorozhkin, G. de With, and J. Loos, "Atomic force and shear force based tip-enhanced Raman spectroscopy and imaging," Nanotechnology, vol. 18, Aug 2007.