石墨烯是一種二維材料，擁有良好的導電性和導熱性，並被廣泛研究應用。石墨烯奈米帶是一種引領至準一維領域的石墨烯衍生物，其在量子侷限效應的作用下展現出別於過往材料的熱電特性，因此被視為潛在的高效率熱電材料。本論文探討了有限長度的石墨烯奈米帶，並以電極線接觸扶手形邊緣(Armchair edge)來提供載子，研究其奈米帶及鋸齒型邊緣(Zigzag edge)對電子傳導性的影響。我們通過改變溫度、奈米帶長寬以及接觸電極使用的金屬材料，來觀察其對石墨烯奈米帶的電導、席貝克係數、功率因子及熱電優值等造成的變化。研究發現，石墨烯奈米帶在不同條件下具有不同的熱電特性，這些特性為其在熱電領域的應用提供了基礎。本研究為進一步了解石墨烯奈米帶在熱電轉換中的機制提供了重要的參考。

Graphene is a two-dimensional material that has been demonstrated to exhibit excellent electrical and thermal conductivity in previous experiments. Graphene nanoribbons(GNRs), in particular, have led to quasi-one-dimensional systems and, under the influence of quantum confinement effects, hold promise as high-efficiency thermoelectric materials. This study investigates the impact of zigzag edge of GNR contact on the electronic transport of finite-length graphene nanoribbons with armchair edges coupled to electrodes. We have demonstrated the unique thermoelectric properties of the GNRs under various in temperatures, ribbon lengths, widths, and the contacted electrodes. Our find says that we have significant insight on thermoelectric properties of GNRs.

[1] Y. M. Lin and M. S. Dresselhaus. Thermoelectric properties of superlattice nanowires. Phys. Rev. B 68, 075304 (2003).
[2] L. D. Hicks and M. S. Dresselhaus. Thermoelectric figure of merit of a one-dimensional conductor. Phys. Rev. B 47, 16631 (1993).
[3] C. Lee, X. D. Wei, J. W. Kysar, and J. Hone. Measurement of the elastic properties and intrinsic strength of monolayer graphene. Science 321, 385 (2008).
[4] P. Cataldi, A. Athanassiou, and I. S. Bayer. Graphene nanoplatelets-based advanced materials and recent progress in sustainable applications. Appl. Sci. 8, 1438 (2018).
[5] X. J. Huang, T. Leng, K. H. Chang, J. C. Chen, K. S. Novoselov, and Z. R. Hu. Graphene radio frequency and microwave passive components for low cost wearable electronics. 2D Mater. 3, 025021, (2016).
[6] J. Molina. Graphene-based fabrics and their applications: A review. RSC Adv. 6, 68261 (2016).
[7] W. J. Hyun, O. O. Park, B. D. Chin. Foldable graphene electronic circuits based on paper substrates. Adv. Mater. 25, 4729 (2013).
[8] E. Pop, V. Varshney, and A. K. Roy. Thermal properties of graphene: Fundamentals and applications. MRS Bull. 32, 1273 (2012).
[9] M. Sang, J. Shin, K. Kim, and K. J. Yu. Electronic and thermal properties of graphene and recent advances in graphene based electronics applications. Nanomaterials 9, 374 (2019).
[10] K. I. Bolotin, K. J. Sikes, Z. Jiang, M. Klima, G. Fudenberg, J. Hone, P. Kim, and H. L. Stormer. Ultrahigh electron mobility in suspended graphene. Solid State Commun. 146, 351 (2008).
[11] A. A. Balandin. Thermal properties of graphene and nanostructured carbon materials. Nature mater. 10, 569 (2011).
[12] L. D. Hicks and M. S. Dresselhaus. Effect of quantum-well structures on the thermoelectric figure of merit. Phys. Rev. B 47, 12727 (1993).
[13] L. D. Hicks, T. C. Harman, X. Sun, and M. S. Dresselhaus. Experimental study of the effect of quantum-well structures on the thermoelectric figure of merit. Phys. Rev. B 53, 10493 (1996).
[14] N. Nakpathomkun, H. Q. Xu, and H. Linke. Thermoelectric efficiency at maximum power in low-dimensional systems. Phys. Rev. B 82, 235428 (2010).
[15] M. Y. Han, B. Ozyulmaz, Y. B. Zhang, and P. Kim. Energy band-gap engineering of graphene nanoribbons. Phys. Rev. Lett. 98, 206805 (2007).
[16] K. Nakada, M. Fujita, G. Dresselhaus, and M. S. Dresselhaus. Edge state in graphene ribbons: Nanometer size effect and edge shape dependence. Phys. Rev. B 54, 17954 (1996).
[17] M. Fujita, K. Wakabayashi, K. Nakada, and K. Kusakabe. Peculiar localized state at zigzag graphite edge. J. Phys. Soc. Jpn. 65, 1920 (1996).
[18] J. M. Cai, P. Ruffieux, R. Jaafar, M. Bieri, T. Braun, S. Blankenburg, M. Muoth, A. P. Seitsonen, M. Saleh, X. L. Feng, K. Muellen, and R. Fasel. Atomically precise bottom-up fabrication of graphene nanoribbons. Nature 466, 470 (2010).
[19] G. D. Nguyen, H. Z. Tsai, A. A. Omrani, T. Marangoni, M. Wu, D. J. Rizzo,
G. F. Rodgers, R. R. Cloke, R. A. Durr, Y. Sakai, F. Liou, A. S. Aikawa,
J. R. Chelikowsky, S. G. Louie, F. R. Fischer, and M. F. Crommie. Atomically precise graphene nanoribbon heterojunctions from a single molecular precursor. Nature Nanotech. 12, 1077 (2017).
[20] D. J. Rizzo, G. Veber, T. Cao, C. Bronner, T. Chen, F. Z. Zhao, H. Rodriguez,
S. G. Louie, M. F. Crommie, and F. R. Fischer. Topological band engineering of graphene nanoribbons. Nature 560, 204 (2018).
[21] K. S. Novoselov, A. K. Geim, S. V. Morozov, D. Jiang, Y. Zhang, S. V. Dubonos,
I. V. Grigorieva, and A. A. Firsov. Electric field effect in atomically thin carbon films.
Science 306, 666 (2004).
[22] C. Berger, Z. M. Song, T. B. Li, X. B. Li, A. Y. Ogbazghi, R. Feng, Z. T. Dai,
A. N. Marchenkov, E. H. Conrad, P. N. First, and W. A. de Heer. Ultrathin epitaxial graphite: 2D electron gas properties and a route toward graphene-based nanoelectronics. J. Phys. Chem. B 108, 19912 (2004).
[23] L. Y. Jiao, L. Zhang, X. R. Wang, G. Diankov, and H. J. Dai. Narrow graphene nanoribbons from carbon nanotubes. Nature 458, 877 (2009).
[24] K. Wakabayashi, M. Fujita, H. Ajiki, and M. Sigrist. Electronic and magnetic properties of nanographite ribbons. Phys. Rev. B 59, 8271 (1999).
[25] M. Fujita, K. Wakabayashi, K. Nakada, and K. Kusakabe. Peculiar localized state at zigzag graphite edge. J. Phys. Soc. Jpn. 65, 1920 (1996).
[26] K. Wakabayashi, M. Sigrist, and M. Fujita. Spin wave mode of edge-localized magnetic states in nanographite zigzag ribbons. J. Phys. Jpn. 67, 2089 (1998).
[27] David M. T. Kuo and Y. C. Chang. Contact effects on thermoelectric properties of textured graphene nanoribbons. Nanomaterials 12, 3357 (2022).
[28] Y. Matsuda, W. Q. Deng, and W. A. Goddard. Contact resistance for “end-contacted” metal-graphene and metal-nanotube interfaces from quantum mechanics.
J. Phys. Chem. C 114, 17845 (2010).
[29] David M. T. Kuo. Effects of metallic electrodes on the thermoelectric properties of zigzag graphene nanoribbons with periodic vacancies. J. Phys.: Condens. Matter 35, 305301 (2023).
[30] H. Haug and A. P. Jauho. Quantum kinetics in transport and optics of semiconductors. (Springer, Heidelberg, 1996).
[31] David M. T. Kuo. Thermoelectric and electron heat rectification properties of quantum dot superlattice nanowire arrays. AIP Advances 4, 045222 (2020).
[32] Y. Meir and N. S. Wingreen. Landauer formula for the current through an interacting electron region. Phys. Rev. Lett. 68, 2512 (1992).
[33] T. Yamamoto, S. Watanabe, and K. Watanabe. Universal features of quantized thermal conductance of carbon nanotubes. Phys. Rev. Lett. 92, 075502 (2004).