研究生: |
林敬軒 Ching-Hsuan Lin |
---|---|
論文名稱: |
二硫化錸二維奈米結構之電傳輸特性 Electronic Transport Properties in ReS2 Two-dimensional Nanostructures |
指導教授: |
陳瑞山
Ruei-San Chen |
口試委員: |
邱博文
Po-Wen Chiu 李奎毅 Kuei-Yi LEE 何清華 Ching-Hwa Ho |
學位類別: |
碩士 Master |
系所名稱: |
應用科技學院 - 應用科技研究所 Graduate Institute of Applied Science and Technology |
論文出版年: | 2016 |
畢業學年度: | 104 |
語文別: | 中文 |
論文頁數: | 101 |
中文關鍵詞: | 二硫化錸 、二維材料 、光電導 |
外文關鍵詞: | ReS2, Two-dimensional material, photoconductivity |
相關次數: | 點閱:506 下載:4 |
分享至: |
查詢本校圖書館目錄 查詢臺灣博碩士論文知識加值系統 勘誤回報 |
本論文主要探討以化學氣相傳輸法成長層狀半導體二硫化錸晶體之奈米結構電傳輸特性。利用機械剝離法由二硫化錸單晶分離成二維奈米結構,並利用聚焦式離子束技術製作二維奈米結構之歐姆電極。該層狀半導體在同一層平面(ab-plane)具有非對稱性,結果發現沿平行b晶軸方向製作電極的奈米結構電導率大於垂直b軸方向製作電極的電導率至少三十倍,同時厚度為20到200nm的奈米結構電導率比塊材晶體高出至少兩個數量級。二硫化錸奈米結構載子活化能相較於塊材相對較低。因此推測二硫化錸可能擁有較高的表面傳導率或較高的表面載子濃度,實驗上排除了人為因素包含基板的載子注入、離子束轟擊造成表面損傷以及接觸電阻的影響。此外,藉由光電導量測,觀察到奈米尺度下二硫化錸的光電導傳輸仍受非等向特性影響,平行b軸歸一化光電導增益大於垂直b軸約五十倍。綜合暗電導與光電導量測結果,推測是由非等向性的遷移率所導致。
We report the electronic transport properties in layer semiconductor of rhenium disulphide (ReS2) grown by chemical vapor transport (CVT). The ReS2 layer nanostructure devices were fabricated using focused-ion beam (FIB) deposition and platinum (Pt) as the contact metal. It is found that the electrical conductivity along the b-axis is thirty times higher than that perpendicular to b-axis for nanostructures. The nanostructures prepared by mechanical exfoliation exhibit over two orders of magnitude higher conductivity than that of their bulk counterparts. These results imply the presence of higher surface conductivity or electron surface accumulation in this layer semiconductor system. The smaller activation energy of carrier were also observed for the ReS2 nanoflakes in comparison to the bulk crystals. The potential artificial effects, that could result in a high electron density at the surface, including electron injection from the substrate and surface damage by ion bombardment, were excluded. In addition, the anisotropic photoconductivity was also observer in the ReS2 nanoflakes. The normalized gain along b-axis is fifty times higher than that normal to b-axis. Both the dark conductivity and photoconductivity studies indicate a higher mobility for the electric transport along the b-axis compared to that normal to b-axis.
[1] K. S. Novoselov, A. K. Geim, S. V. Morozov, D. Jiang, Y. Zhang, S. V. Dubonos, I. V. Grigorieva, A. A. Firsov, “Electric Field Effect in Atomically Thin Carbon Films,” Science, Vol. 306, pp.666-669 (2004).
[2] K. S. Novoselov, D. Jiang, F. Schedin, T. J. Booth, V. V. Khotkevich, S. V. Morozov, et al., “Two-dimensional atomic crystals,” Proceedings of the National Academy of Sciences of the United States of America, Vol. 102, pp. 10451-10453 (2005).
[3] A. Splendiani, L. Sun, Y. Zhang, T. Li, J. Kim, C. Y. Chim, G. Galli, and F. Wang, “Emerging Photoluminescence in Monolayer MoS2,” Nano Lett., Vol. 10, pp. 1271-1275 (2010).
[4] K. F. Mak, C. Lee, J. Hone, J. Shan, and T. F. Heinz, “Atomically Thin MoS2: A New Direct-Gap Semiconductor,” Phys. Rev. Lett., Vol. 105, pp. 136805 (2010).
[5] S. Tongay, H. Sahin, C. Ko, A. Luce, W. Fan, K. Liu, J. Zhou, Y. S. Huang, C. H. Ho, J. Y. Yan, D. F. Ogletree, S. Aloni, J. Ji, S. S. Li, J. B. Li, F. M. Peeters, J. Q. Wu, “Monolayer behaviour in bulk ReS2 due to electronic and vibrational decoupling,” Nat. Commun., Vol. 5, pp. 3252 (2014).
[6] R. S. Chen, C. C. Tang, W. C. Shen and Y. S. Huang, “Thickness dependent electrical conductivities and ohmic contacts in transition metal dichalcogenides multilayers,” Nanotechnology, Vol. 25, pp. 415706 (2014).
[7] S. X. Yang, S. Tongay, Q. Yue, Y. T. Li, B. Li, F. Y. Lu, “High Performance Few-layer Mo-doped ReSe2 Nanosheet Photodetectors,” Sci Rep, Vol. 4, pp. 5442 (2014).
[8] E. Zhang, Y. B. Jin, X. Yuan, W. Y. Wang, C. Zhang, L. Tang, S. S. Liu, P. Zhou, W. D. Hu, F. X. Xiu, “ReS2 Based Field-Effect Transistors and Photodetectors,” Adv. Funct. Mater., Vol. 25, pp. 4076-4082 (2015).
[9] E. F. Liu, Y. J. Fu, Y. J. Wang, Y. Q. Feng, H. M. Liu, X. G. Wan, W. Zhou, B. G. Wang, L. B. Shao, C. H. Ho, Y. S. Huang, Z. Y. Cao, L. G. Wang, A. D. Li, J. W. Zeng, F. Q. Song, X. R. Wang, Y. Shi, H. T. Yuan, H. Y. Hwang, Y. Cui, F. Miao, D. Y. Xing, “Integrated digital inverters based on two-dimensional anisotropic ReS2 field-effect transistors,” Nat. Commun., Vol. 6, pp. 6991 (2015).
[10] C. M. Corbett, C. McClellan, A. Rai, S. S. Sonde, E. Tutuc, S. K. Banerjee, “Field Effect Transistors with Current Saturation and Voltage Gain in Ultrathin ReS2,” ACS Nano, Vol. 9, pp. 363-370 (2015).
[11] Y. C. Lin, H. P. Komsa, C. H. Yeh, T. Bjorkman, Z. Y. Liang, C. H. Ho, Y. S. Huang, P. W. Chiu, A. V. Krasheninnikov, K. Suenaga, “Single-Layer ReS2 Two-Dimensional Semiconductor with Tunable In-Plane Anisotropy,” ACS Nano, Vol. 9, pp. 11249-11257 (2015).
[12] K. Xu, H. X. Deng, Z. X. Wang, Y. Huang, F. Wang, S. S. Li, J. W. Luo, J. He, “Sulfur vacancy activated field effect transistors based on ReS2 nanosheets,” Nanoscale, Vol. 7, pp. 15757-15762 (2015).
[13] 張冠英, “X光能譜分析儀”.
[14] B. D. Cullity, S. R. Stock, “Elements of X-ray diffraction,” Prentice Hall, New Jersey (2001).
[15] P. E. J. Flewitt and R. K. Wild, “Physical methods for materials characterization,” IOP Publishing, Bristol, (1994).
[16] A. A. Tseng, K. Chen, C. D. Chen, and K. J. Ma, “Electron Beam Lithography in Nanoscale Fabrication: Recent Development,” IEEE Trans. Electron. Packag. Manuf., Vol. 26, pp. 141–149, (2003).
[17] A. A. Tseng, “Recent developments in micromilling using focused ion beam technology,” J. Micromech. Microeng., Vol. 14, pp. R15–R34, (2004).
[18] A. A. Tseng, “Recent Developments in Nanofabrication using Focused Ion Beams,” Small, Vol. 1, pp. 924–939, (2005).
[19] F. Braet, R. De Zanger, and E. Wisse, “Drying cells for SEM, AFM and TEM by hexamethyldisilazane: a study on hepatic endothelial cells,” Journal of Microscopy, Vol. 186, pp. 84–87, (1997)
[20] Y. M. Chang, H. Kim, J. H. Lee, and Y. W. Song, “Multilayered graphene efficiently formed by mechanical exfoliation for nonlinear saturable absorbers in fiber mode-locked lasers,” Appl. Phys. Lett., Vol. 91970, pp.211102 (2010).
[21] C. Y. Nam, D. Tham, J. E. Fischer, “Disorder effects in focused-ionbeam-deposited Pt contacts on GaN nanowires,” Nano Lett., Vol. 5, pp. 2029-2033 (2005).
[22] D. A. Chenet, O. B. Aslan, P. Y. Huang, C. Fan, A. M. van der Zande, T. F. Heinz, J. C. Hone, “In-Plane Anisotropy in Mono- and Few-Layer ReS2 Probed by Raman Spectroscopy and Scanning Transmission Electron Microscopy,” Nano Lett., Vol. 15, pp. 5667-5672 (2015).
[23] C. H. Ho, Y. S. Huang, K. K. Tiong, “In-plane anisotropy of the optical and electrical properties of ReS2 and ReSe2 layered crystals,” J. Alloy. Compd., Vol. 317, pp. 222-226 (2001).
[24] C. Y. Nam, D. Tham, and J. E. Fischer, “Disorder effects in focused-ion-beam-deposited Pt contacts on GaN nanowires,” Nano Lett., Vol. 5, pp. 2029–2033 (2005).
[25] K. Dolui, I. Rungger, S. Sanvito, “Origin of the n-type and p-type conductivity of MoS2 monolayers on a SiO2 substrate,” Phys. Rev. B, Vol. 87, pp. 165402 (2013).
[26] I. Mahboob, T. D. Veal, C. F. McConville, H. Lu, W. J. Schaff, “Intrinsic Electron Accumulation at Clean InN Surfaces,” Phys. Rev. Lett., Vol. 92, pp. 036804 (2004).
[27] P. Bhattacharya, “Semiconductor optoelectronic devices,” Prentice Hall, New Jersey, Vol. 8, pp. 346-351, (1997).
[28] M. Razeghi, A. Rogalski, “Semiconductor ultraviolet detectors,” J.Appl. Phys., Vol. 79, pp. 7433-7473, (1996).
[29] R. S. Chen, H. Y. Chen, C. Y. Lu, K. H. Chen, C. P. Chen, L. C. Chen, Y. J. Yang, “Ultahigh photocurrent gain in m-axial GaN nanowires,” Appl. Phys. Lett., Vol. 91, pp. 223106 (2007).
[30] R. S. Chen, W. C. Wang, C. H. Chan, H. P. Hsu, L. C. Tien, Y. J. Chen, “Photoconductivities in monocrystalline layered V2O5 nanowires grown by physical vapor deposition,” Nanoscale Res. Lett., Vol. 8, pp. 443 (2013).
[31] J. D. Prades, R. Jimenez-Diaz, F. Hernandez-Ramirez, L. Fernandez-Romero, T. Andreu, A. Cirera, A. Romano-Rodriguez, A. Cornet, J. R. Morante, S. Barth, S. Mathur, “Toward a systematic understanding of hotodetectors based on individual metal oxide nanowires,” J. Phys. Chem. C, Vol. 112, pp. 14639-14644, (2008).
[32] C. Fabrega, F. Hernandez-Ramirez, J. D. Prades, R. Jimenez-Diaz, T. Andreu, J. R. Morante, “On the photoconduction properties of low 93 resistivity TiO2 nanotubes,” Nanotechnology, Vol. 21, pp. 445703 (2010).
[33] A. Beiser, “Concepts Of Modern Physics,” McGraw-Hill Education (India) Pvt Limited (2003).