研究生: |
沈韋竹 Wei-Chu Shen |
---|---|
論文名稱: |
二硫化鉬及二硫化鎢層狀半導體奈米結構之厚度相依電傳輸特性 Thickness-dependent Electric Properties in MoS2 and WS2 Layer Semiconductor Nanostructures |
指導教授: |
黃鶯聲
Ying-Sheng Huang 陳瑞山 Ruei-San Chen |
口試委員: |
何清華
Ching-Hwa Ho 李奎毅 Kuei-Yi Lee 趙良君 Liang -Chiun Chao |
學位類別: |
碩士 Master |
系所名稱: |
電資學院 - 電子工程系 Department of Electronic and Computer Engineering |
論文出版年: | 2015 |
畢業學年度: | 103 |
語文別: | 中文 |
論文頁數: | 110 |
中文關鍵詞: | 二硫化鉬 、二硫化鎢 、層狀半導體 、奈米結構 、電導率 、光電導 、氧敏化光電導機制 |
外文關鍵詞: | molybdenum disulphide, tungsten disulphide, layer semiconductor, nanostructure, conductivity, photoconductivity, oxygen-sensitized photoconduction mechanism |
相關次數: | 點閱:433 下載:17 |
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 |
本論文主要是探討量子侷限效應外層狀半導體具有不同厚度的二硫化鉬(MoS2)及二硫化鎢(WS2)奈米結構之電傳輸特性。研究結果發現利用簡單的機械剝離法所產生的奈米結構表現出比塊材晶體要高出了幾個數量級的電導率。與此同時,也觀察到二硫化鉬和二硫化鎢奈米結構其載子的活化能相較於同質的塊材還要小,這些結果暗示這兩種層狀半導體可能擁有較高的表面傳導率或較高的表面載子濃度。實驗上也排除了人為因素所影響導致在表層形成較高電子濃度之可能性,包含基板的載子注入與由離子束轟擊層狀材料造成表面損傷的情形。該結果進一步驗證這類層狀材料表面電子累積是屬於材料本質的特性,並有可能適用於多數的過渡金屬硫屬化合物(transition metal dichalcogenide semiconductor)層狀的半導體。此外,藉由532奈米波長雷射激發,兩種材料的塊材與奈米結構皆表現出明顯的光電流反應。光電流隨著入射光光強度增加呈現線性增加。藉由計算光電導增益值發現奈米結構高於塊材近六個數量級。環境變化之光電導量測亦顯示這兩種二維奈米材料皆遵循氧氣敏化光電導機制。
Thickness-dependent electronic transport properties in the molybdenum disulphide (MoS2) and the tungsten disulphide (WS2) two-dimensional (2D) nanostructures beyond quantum confinement scale were observed and investigated. It is found that the nanoflakes produced by simple mechanical exfoliation exhibit several orders of magnitude higher conductivity than their bulk counterparts. The smaller activation energies of carrier were also observed for the MoS2 and WS2 nanoflakes in comparison to the bulk counterparts. These results imply the presence of higher surface conductivity or electron surface accumulation in the layer semiconductor systems. In addition, 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. This result further indicates the proposed surface electron accumulation is an inherent characteristic, which might be generally applicable to the transition metal dichalcogenide (TMD) layer semiconductors. In addition, photoconductive properties in the MoS2 and WS2 nanostructures and bulks by the excitation of the wavelength of 532 nm were also investigated. The photoconductive gains of the nanostructures are six orders of magnitude higher than their bulk counterparts. The environments-dependent photoconductivity indicates these layer nanomaterials follow the oxygen-sensitized photoconduction (PC) mechanism.
[1] H. Tributsch, “Hole Reactions from d-Energy Band of Layer Type Group VI Transition Matel Dichalcogenides: New Perspectives for Electrochemical Solar Energy Conversion,” J. Electrochem. Soc., vol. 125, pp. 1086-1093 (1978)
[2] Radisavljevic, B., Radenovic, A., Brivio, J., Giacometti, V., Kis, A. Single-layer MoS2 transistors. Nature Nanotech. 6, 147-150 (2011).
[3] Radisavljevic, B. & Kis, A. Mobility engineering and a metal-insulator transition in monolayer MoS2. Nature Mater. 12, 815-820 (2013).
[4] Liu, H., Neal, A. T., Ye, P. D. Channel length scaling of MoS2 MOSFETs. ACS Nano 6, 8563-8569 (2012).
[5] Wu, W., De, D., Chang, S. C., Wang, Y., Peng, H., Bao, J., Pei, S. S. High mobility and high on/off ratio field-effect transistors based on chemical vapor deposited single-crystal MoS2 grains. Appl. Phys. Lett. 102, 142106 (4 pages) (2013).
[6] Min, S., Lu, G. Sites for High Efficient Photocatalytic Hydrogen Evolution on a Limited-Layered MoS2 Cocatalyst Confined on Graphene Sheets-The Role of Graphene. J. Phys. Chem. C 116, 25415-25424 (2012).
[7] Xiang, Q., Yu, J., Jaroniec, M. Synergetic Effect of MoS2 and Graphene as Cocatalysts for Enhanced Photocatalytic H2 Production Activity of TiO2 Nanoparticles. J. Am. Chem. Soc. 134, 6575-6578 (2012).
[8] Chang, K., Chen, W. L-Cysteine-Assisted Synthesis of Layered MoS2/Graphene Composites with Excellent Electrochemical Performances for Lithium Ion Batteries. ACS Nano 5, 4720-4728 (2011).
[9] David, L., Bhandavat, R., Singh, G. MoS2/Graphene Composite Paper for Sodium-Ion Battery Electrodes. ACS Nano 8, 1759-1770 (2014).
[10] Liu, C. J., Tai, S. Y., Chou, S. W., Yu, Y. C., Chang, K. D., Wang, S., Chien, F., S. S., Lin, J. Y., Lin, T. W. Facile synthesis of MoS2/graphene nanocomposite with high catalytic activity toward triiodide reduction in dye-sensitized solar cells. J. Mater. Chem. 22, 21057-21064 (2012).
[11] Bertolazzi, S., Krasnozhon, D., Kis, A. Nonvolatile Memory Cells Based on MoS2/Graphene Heterostructures. ACS Nano 7, 3246-3252 (2013).
[12] Choi, M. S., Lee, G. H., Yu, Y. J., Lee, D. Y., Lee, S. H., Kim, P., Hone, J., Yoo, W. J. Controlled charge trapping by molybdenum disulphide and graphene in ultrathin heterostructured memory devices. Nature Commun. 4, 1624 (7 pages) (2013).
[13] A. P. Alivisatos, “Perspectives on the physical chemistry of semiconductor nanocrystals,” J. Phys. Chem., vol. 100, pp. 13226 (1996).
[14] P. Moriarty, “Nanostructured materials,” Rep. Prog. Phys., vol. 64, pp. 297–381 (2001).
[15] A. D. Yoffe, “Low-dimensional systems: quantum size effects and electronic properties of semiconductor microcrystallites (zero-dimensional systems) and some quasi-two-dimensional systems,” Adv. Phys., vol. 42, pp. 173–262 (1993).
[16] X. M. Qian and S. M. Nie, “Single-molecule and single-nanoparticle SERS: from fundamental mechanisms to biomedical applications,” Chem. Soc. Rev., vol. 37, pp. 912–920 (2008).
[17] S. Nie and S. R. Emory, “Probing single molecules and single nanoparticles by surface-enhanced raman scattering,” Science, vol. 275, pp. 1102–1106 (1997).
[18] 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).
[19] 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).
[20] B. Radisavljevic, A. Radenovic, J. Brivio, V. Giacometti, and A. Kis, “Single-layer MoS2 transistors,” Nature Nanotechnol., vol. 6, pp. 147-150 (2011).
[21] H. Wang, L. Yu, Y. H. Lee, Y. Shi, A. Hsu, M. L. Chin, L. J. Li, M. Dubey, J. Kong, and T. Palacios, “Integrated Circuits Based on Bilayer MoS2 Transistors,” Nano Lett., vol. 12, pp. 4674-4680 (2012).
[22] A. Castellanos-Gomez, M. Barkelid, A. M. Goossens, V. E. Calado, H. S. J. van der Zant, and G. A. Steele, “Laser-Thinning of MoS2: On Demand Generation of a Single-Layer Semiconductor,” Nano Lett., vol. 12, pp. 3187-3192 (2012).
[23] Y. Yoon, K. Ganapathi, and S. Salahuddin, “How Good Can Monolayer MoS2 Transistors Be?,” Nano Lett., vol. 11, pp. 3768-3773 (2011).
[24] W. Choi, M. Y. Cho, A. Konar, J. H. Lee, G. B. Cha, S. C. Hong, S. Kim, J. Kim, D. Jena, J. Joo, and S. Kim, “High-Detectivity Multilayer MoS2 Phototransistors with Spectral Response from Ultraviolet to Infrared,” Adv. Mater. Vol. 24, pp. 5832-5836 (2012).
[25] D. J. Late, B. Liu, H. S. S. Ramakrishna Matte, C. N. R. Rao, and V. P. Dravid, “Rapid Characterization of Ultrathin Layers of Chalcogenides on SiO2/Si Substrates,” Adv. Funct. Mater. Vol. 22, pp. 1894-1905 (2012).
[26] F. Wypych, "Molybdenum disulfide, a multifunctional and remarkable material," Quimica Nova, vol. 25, pp. 83-88, Jan-Feb (2002).
[27] P. E. J. Flewitt and R. K. Wild, “Physical methods for materials characterization,” IOP Publishing, Bristol (1994).
[28] 張冠英, “X 光能譜分析儀”.
[29] A. Beiser, "Concepts Of Modern Physics," McGraw-Hill Education (India) Pvt Limited (2003).
[30] D. Yang and R. F. Frindt, "Powder x‐ray diffraction of two‐dimensional materials," J. Appl. Phys., vol. 79, pp. 2376-2385 (1996).
[31] 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).
[32] A. A. Tseng, “ Recent developments in micromilling using focused ion beam technology,“ J. Micromech. Microeng., Vol. 14, pp. R15–R34 (2004).
[33] A. A. Tseng, “Recent Developments in Nanofabrication using Focused Ion Beams,” Small, Vol. 1, pp. 924–939 (2005).
[34] 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, pages 84–87 (1997)
[35] 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. 97, 211102 (3pp) (2010).
[36] 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).
[37] Li, H., Zhang, Q., Yap, C. C. R., Tay, B. K., Edwin, T. H. T., Olivier, A., Baillargeat, D. From Bulk to Monolayer MoS2: Evolution of Raman Scattering. Adv. Funct. Mater. 22, 1385-1390 (2012).
[38] Berkdemir, A., Gutierrez, H. R., Botello-Mendez, A. R., Perea-Lopez, N., Elias, A. L., Chia, C. I., Wang, B., Crespi, V. H., Lopez-Urias, F., Charlier, J. C., Terrones, H., Terrones, M. Identification of individual and few layers of WS2 using Raman Spectroscopy. Sci. Rep. 3, 1755 (8 pages) (2013).
[39] Chen, R. S., Tang, C. C., Shen, W. C., Huang, Y. S. Thickness-dependent electrical conductivities and ohmic contacts in transition metal dichalcogenides multilayers. Nanotechnology 25, 415706 (9 pages) (2014).
[40] Tiong, K. K., Liao, P. C., Ho, C. H., Huang, Y. S. Growth and characterization of rhenium-doped MoS2 single crystals. J. Crystal Growth 205, 543-547 (1999).
[41] Yen, P. C., Huang, Y. S., Tiong, K. K. The growth and characterization of rhenium-doped WS2 single crystals. J. Phys.: Condens. Matter 16, 2171-2180 (2004).
[42] K. Dolui, I. Rungger, and S. Sanvito, "Origin of the n-type and p-type conductivity of MoS2 monolayers on a SiO2 substrate," Physical Review B, vol. 87, p.7 (2013).
[43] I. Mahboob, T. D. Veal, and C. F. McConville, “Intrinsic Electron Accumulation at Clean InN Surfaces,” PhysRevLett., Vol. 92, pp. 036804 (2004).
[44] K. F. Mak, C. Lee, J. Hone, J. Shan, and T. F. Heinz, "Atomically Thin MoS2: A New Direct-Gap Semiconductor," Physical Review Letters, vol. 105, p. 4 (2010).
[45] A. L. Elias, N. Perea-Lopez, A. Castro-Beltran, A. Berkdemir, R. T. Lv, S. M. Feng, A. D. Long, T. Hayashi, Y. A. Kim, M. Endo, H. R. Gutierrez, N. R. Pradhan, L. Balicas, T. E. M. Houk, F. Lopez-Urias, H. Terrones, M. Terrones.,"Controlled Synthesis and Transfer of Large-Area WS2 Sheets: From Single Layer to Few Layers," Acs Nano, vol. 7, pp. 5235-5242 (2013).
[46] R. S. Chen, T. H. Yang, H. Y. Chen, L. C. Chen, K. H. Chen, Y. J. Yang, C. H. Su, C. R. Lin, "Photoconduction mechanism of oxygen sensitization in InN nanowires," Nanotechnology, vol. 22, p. 5 (2011).