中文摘要

本論文係有關摻雜鎵之氧化鋅奈米柱的合成與特性分析。首先以溶膠凝膠法合成氧化鋅晶種，旋轉塗佈於ITO導電玻璃上，再以水熱法製備沿C-軸成長之摻雜鎵的氧化鋅奈米柱，探討摻雜不同鎵濃度對其形態及光學與電學性質的影響。
氧化鋅奈米柱摻雜鎵的主要目的是要以此調控氧化鋅半導體的能階及提高其載子濃度，以便應用於光電化學元件或太陽能電池。製得之氧化鋅奈米柱以掃瞄式電子顯微鏡及穿透式電子顯微鏡分析其形態，以X射線繞射儀、螢光光譜儀及紫外線/可見光光譜儀分析其結晶構造及光學性質。結果發現，摻雜鎵後，氧化鋅奈米柱的結晶性大幅下降且放光波長有藍位移現象。藉著高解析穿透式電子顯微鏡及化學分析電子光譜儀的鑑定，可判知鎵已成功導入氧化鋅晶格中。
為探討摻雜鎵之氧化鋅奈米柱的特性，首先以四點式探針量測其導電性，其次藉與Pt接觸製備蕭特基式接觸，並以三極式電化學系統觀察其在光電化學電池中之效能。導電性量測顯示，摻雜鎵會導致電導度的降低，推測是因鎵的導入會造成缺陷所致。由蕭特基式接觸及光電化學電池之電流-電壓關係可知，當鎵摻雜濃度約為0.5%時可得最佳的電流值。因能隙與載子濃度為影響電流密度大小的兩個主要因素，隨著鎵摻雜濃度的增加，對摻雜鎵之氧化鋅奈米柱的電流變化有相反的影響，所以在不同摻雜濃度下會對電流密度有不同的影響。

Abstract

This thesis concerns the synthesis and character-ization of Ga-doped ZnO nanorods. Firstly, ZnO seeds were synthesized by sol-gel method and spin-coated on the surface of ITO substrate. Then, Ga-doped ZnO nanorods were grown on the seed layer along the C axis via hydrothermal technique. The effects of Ga-doping concentration on the morphology and the optical and electrical properties were investigated.
Doping Ga into ZnO lattices was expected to modulate the energy bandgap and increase carrier concentration of ZnO semiconductor for the applications in photoelectro-chemical devices or solar cells. The resultant ZnO nanorods were analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) to observe their morphology. Their crystalline structure and optical properties were characterized by X-ray Diffraction (XRD), photoluminescence (PL), and UV/VIS spectro-photometer. The results revealed that the crystallinity obviously decreased and the UV emission peak was blue-shifted after Ga doping. From the HRTEM and XPS analyses, it was demonstrated that Ga atoms were really doped into the ZnO lattices.
In order to know the characteristics of Ga-doped ZnO nanorods, four-point probe station was used to measure their conductance. After that, Schottky contact was made by contacting Pt to Ga-doped ZnO and a three-electrode electrochemical system was employed to observe the performance of Ga-doped ZnO in a photoelectrochemical cell. The conductance measurement revealed that the conductance decreased when the doping concentration increased. This might be due to the defect inside the lattice resulted by Ga doping. From the I-V (current-voltage) relation of the Schottky contact and photoelectro-chemical cell, there existed an optimum doping concentration (about [Ga] = 0.5%) to enhance the current. Because energy bandgap and carrier concentration were two main factors to affect magnitude of current density, the opposite current behaviors of Ga-doped ZnO nanorods appeared as the Ga concentration increased. Thus, the different doping level would induce the different influence on the current density.

參考文獻
1.L. Vayssieres, K. Keis, A. Hagfeldt, and S. E. Lindquist, J. Phys. Chem. B, 105, 3350 (2001).
2.周黃蔚, 氧化鋅奈米柱之光學特性研究, 國立東華大學, 材料科學與工程研究所碩士論文 (2007).
3.蔡嬪嬪, “奈米科技發展現況與前景”, 工業技術研究院奈米科技研發中心, 東華大學奈米科技論壇 (2004).
4.E. Burstein, Phys. Rev., 93, 632 (1954).
5.T. S. Moss, Proc. Phys. Soc. B, 67, 775 (1954).
6.Z. L. Wang, X. Y. Kong, Y. Ding, P. Gao, W. L. Hughes, R. Yang, and Y. Zhang, Adv. Funct. Mater., 14, 935 (2004).
7.R. S. Wagner, and W. C. Ellis, Appl. Phys. Lett., 4, 89 (1964).
8.E. I. Givargizov, J Crystal growth, 31, 20 (1975).
9.S. T. Lee, N. Wang, and Y. F. Zhang, MRS Bulletin, 24, 36 (1999).
10.W. S. Shi, H. Y. Peng, N. Wang, C. P. Li, L. Xu, C. S. Lee, R. Kalish and S. T. Lee, J. Am. Chem. Soc., 123, 1995 (2001).
11.Z. Dohnalek, G. A. Kimmel, D. E. McCready, and J. S. Young, J. Phys. Chem. B, 106, 3526 (2002).
12.K. D. Harris, K. L. Westra, and M. J. Brett, Electrochem. and Solid-State Lett., 4, C39 (2001).
13.T. Smy, D. Vick, M. J. Brett, S. K. Dew, A. T. Wu, J. C. Sit, and K.D. Harris, J. Vac. Sci. Techno. A., 18, 2507 (2000).
14.R. Messier, V. C. Venugopal, and P. D. Sunal, J. Vac. Sci. Technol. A, 18, 1538 (2000).
15.M. Malac., R. F Egerton, M. J. Brett, and B. Dick, J. Vac. Sci. Technol. B, 17, 2671 (1999).
16.F. Liu, M. T. Umlor, L. Shen, J. Weston, W. Eads, J. A. Barnard, and G. J. Mankey, J. Appl. Phys., 85, 5486 (1999).
17.K. Robbie, M. J. Brett, and A. Lakhtakia, Nature, 384, 616 (1996).
18.K. Robbie, and M. J. Brett, J. Vac. Sci. Technol. A, 15, 1460 (1997).
19.Y. Xia, and P. Yang, Adv. Mater., 15, 353 (2003).
20.A. P Alivisatos, Nature, 404, 59 (2000).
21.A. P Alivisatos, J. Am. Chem. Soc., 122, 12700 (2000).
22.J. H. Park, Y. J. CHoi, and J. G. Park, J. Cryst. Growth., 280, 161 (2005).
23.Y. Zhang, Chem. Mater. , 14, 3564 (2002).
24.X. Wang, Q. Li, Z. Liu, J. Zhang, Z. Liu, and R. Wang, Appl. Phys. Lett.,84 , 4941 (2004).
25.R. C. Wang, C. P. Liu, and J. L. Huang, S., J. Chen, Appl. Phys. Lett., 88, 023111 (2006).
26.楊明輝, 工業材料, 179, 134 (1999).
27.H. L. Hartnagel, A. L. Dawar, A. K. Jain, and C. Jagadish, Institute of Physics Publishing, 288 (1995).
28.J. G. Lu, Z. Z. Ye, Y. J. Zeng, L. P. Zhu, L. Wang, J. Yuan, and B. H. Zhao, J. Appl. Phys., 100, 073714 (2006).
29.J. Briscoe, D. E. Gallardo, and S. Dunn, Chem. Commun., 10, 1273 (2009).
30.李素敏、趙玉濤、何維鳳、戴起勳、張釗, “磁控濺射製備柔性襯底ZnO : Ga 透明導電膜研究”, 江蘇大學材料科學與工程學院, 江蘇鎮江 212013.
31.B. G. Streetman, and S. Banerjee, “Solid state electronic devices 5th edition”, (2001).
32.B. E. Sernelius, K. F. Berggren, Z. C. Jin, I. Hamberg, C., and G. Granqvist, Physical Review B, 37, 10244 (1988).
33.Z. K. Tang, G. K. L. Wong, P. Yu, M. Kawasaki, A. Ohtomo, H.Koinuma, and Y. Segawa, Appl. Phys. Lett., 72, 3270 (1998).
34.D. C. Reynolds, D. C. Lock, and B. Jogai, Solid State Commun., 99, 873 (1996).
35.D. M. Bagnall, Y. F. Chen, Z. Zhu, T. Yao, S. Koyama, M. Y. Shen, and T. Goto, Appl. Phys. Lett., 70, 2230 (1997).
36.Numerical Data and Functional Relationships in Scirnce and Technology./v.22, Subvolume a. Intrinsic Properties of Group Ⅳ Elements and Ⅲ-Ⅴ, Ⅱ-Ⅵ and Ⅰ-Ⅶ Compounds., Berlin:/ Springer -Verlag, / 1987.
37.Y. Chen, D. M. Bagnall, H. Koh, K. Park, Z. Zhu, and T. Yao, J. Appl. Phys., 84, 3912 (1998).
38.http://oxide.rlem.titech.ac.jp/kawasaki/ZnO/ZnO.htm.
39.D. C. Look, Mater. Sci. Eng. B, 80, 383 (2001).
40.W. S. Hu, Z. G. Liu, R. X. Wu, Y.-F. Chen, W. Ji, T. Yu, and D. Feng, Appl. Phys. Lett., 71, 548 (1997).
41.S. Ezhilvalavan and T. R N. Kutty, Appl. Phys. Lett., 69, 3540 (1996).
42.S. Kohiki, M. Nishitani, and T. Wada., J. Appl. Phys., 75, 2069 (1994).
43.R. Wang, L. L. H. King, and A. W. Sleight., J. Mater Res., 11, 1659 (1996).
44.B. Sang, A. Yamada, and M. Konagai., Sol. Energy Mater. Sol. Cells, 49, 19 (1997).
45.K. J. Kim and Y. R. Park, Appl. Phys. Lett., 78, 475 (2001).
46.M. Miyazaki, K. Sato, A. Mitsui and H. Nishimura., J. Non-Cryst. Solid, 201, 895 (1997).
47.楊明輝, 工業材料, 11月 (2001).
48.R. F. Service, Science, 276, 895 (1997).
49.郭旭祥, Al薄膜氣體感測器之研究, 國立成功大學, 材料科學及工程學系碩士學位論文 (2000).
50.H. Ohta, M. Orita, and M. Hirano., J. Appl. Phys., 89, 5720 (2001).
51.H. Kawazoe, M. Tasukawa, H. Hyodo, M. Kurita, H. Yanagi, and H. Hosono. Nature, 389, 939 (1997).
52.A. Kudo, H. Yanagi, H. Hosono, and H. Kawazoe, Appl. Phys. Lett.,73,220 (1998).
53.Y. R. Ryu, W. J. Kim, and H. W. White, J. Crystal Growth ,219 , 419 (2000).
54.吳坤陽, 溶膠凝膠法製備含銀之AZO透明導電膜的研究, 國立成功大學, 化學工程所碩士學位論文(2005).
55.“sol-gel technologies and their products”, http://www.chemat.com/, CHEMAT Technology, Inc.
56.C. J. Brinker, and G. W. Scherer, “Sol-gel Science: the physics and chemistry of sol-gel processing”, Academic Press, Inc. (1990).
57.納米複合材料, 徐國財, 張立德, 化學工業出版社 (2001).
58.謝坤龍, 鈀銀合金/氧化鋁複合膜之特性研究:以溶膠凝膠法修是基材孔徑之探討, 國立成功大學, 化學工程所碩士論文 (2000).
59.Q. Li, V. Kumar, Y. Li, H. Zhang, T. J. Marks, and R. P. H. Chang, Chem. Mater., 17, 1001 (2005).
60.L. E. Greene, M. Law, D. H. Tan, M. Montano, J. Goldberger, G. Somorjai, and P. Yang, Nano Lett., 5, 1231 (2005).
61.K. Govender, D. S. Boyle, P. B. Kenway, and P. O’Brien, J. Mater. Chem., 14, 2575 (2004).
62.R. W. Nosker, P. Mark, and J. D. Levine, Surf. Sci., 19, 291 (1970).
63.L. Spanhel, and M. A. Anderson, J. Am. Chem. Soc., 113, 2826 (1991).
64.C. Pacholski, A. Kornowski, and H. Weller, Angew. Chem. Int. Ed., 41, 1188 (2002).
65.B. Liu, and H. C. Zeng, Langmuir, 20, 4196 (2004).
66.L. Vayssieres, K. Keis, S. E. Lindquist, and A. Hagfeldt, J. Phys. Chem. B., 105, 3350 (2001).
67.L. Vayssieres, K. Keis, A. Hagfeldt, and S. E. Lindquist, Chem. Mater., 13, 4395 (2001).
68.L. Vayssieres, Adv. Mater., 15, 464 (2003).
69.Z. R. Tian, J. A. Voigt, J. Liu, B. Mckenzie, and M. J. Mcdermott, J.Am. Chem. Soc., 124, 12954 (2002).
70.L. E. Greene, M. Law, J. Goldberger, F. Kim, J. C. Johnson, Y. Zhang, R. J. Saykally, and P. Yang, Angew. Chem. Int. Ed., 42, 3031 (2003).
71.Y. Tak and K. Yong, J. Phys. Chem. B, 109, 19263 (2005).
72.K. Govender, D. S. Boyle, P. B. Kenway, and P. O'Brien, J. Mater. Chem., 14, 2575 (2004).
73.陳毓民, 金屬對P型硒化鎵之接觸特性, 崑山科技大學, 電子工程研究所碩士學位論文 (2006).
74.半導體物理與元件, Donald A. Neamen著, 楊賜麟譯, 滄海書局(2005)
75.Z. L. Pei, C. Sun, M. H. Tan, J. Q. Xiao ,D. H. Guan, R. F. Huang, and L.S. Wen, Appl. Phys, 90, 3432 (2001).
76.G. W. Castellan, “Physical Chemistry”, and 2nd ED, University of Maryland, pp 806-817 (1971).
77.S. H. Maron, and J. B. Lando, “Fundamentals of Physical Chemistry”, Macmillan Publishing Co. Inc., New York, pp.720-740 (1974).
78.N. Serpone, and E. Pelizzetti, “Photocatalysis; Fundamentals, and Application”, Wiley-Inter Science, Canada (1989).
79.C. M. Doede, and C. A. Walker, “Photochemical Engineering”, Chemical Engineering, pp. 159-178, February (1955).
80.H. O. Finkdea (ED.), “Semiconductor Electrodes”, P. 2, Elsevier Science Publishing Co. Inc., New York (1998).
81.G. Prasad, N. N. Rao, and O. N. Srirastava, Int. J. Hydrogen Energy, 13, 399 (1988).
82.T. R. N. kutty, L. Gorrathi Devi, and M. Arudaithai, Sol. Energy Mater., 20, 307 (1990).
83.S. Shet, K. S. Ahn, Y. Yan, T. Deutsch, K. M. Chrustowski, J. Turner, M. Al–Jassim, and N. Ravindra, J. Appl. Phys., 103, 073504 (2008).
84.T. Bak, J. Nowotny, M. Rekas, and C.C. Sorrell, Int. J. Hydrogen Energy, 27, 991 (2002).
85.J. Nowotny, C. C. Sorrell, T. Bak, and L. R. Sheppard, Sol. Energy, 78, 593 (2005).
86.M. A. Butler and D. S. Ginley, J. Mater. Sci., 15, 1 (1980).
87.A. J. Bard and M. S. Wrighton, J. Electrochem. Soc., 124, 1706 (1977).
88.R. N. Noufi, R. N. Noufi, P. A. Kohl, S. N. Frank, and A. J. Bard, J. Electrochem. Soc., 125, 246 (1978).
89.M. Grätzel, Nature, 414, 338 (2001).
90.S. N. Frank and A. J. Bard, J. Electrochem. Soc., 125, 246 (1978).
91.U. Ozgur, Ya. I. Alivov, C. Liu, A. Teke, M. A. Reshchikov, S. Doan, V. Avrutin, S. J. Cho, and H. Morkoc, J. Appl. Phys., 98, 041301 (2005).
92.http://www.instrument.com.cn/bbs/shtml/20070401/789347/.
93.H. L. Hartnagel, A. L. Dawar, A. K. Jain, and C. Jagadish,“Semiconducting Transparent Thin Films”, Institute of Physics Publishing (1995).
94.B. G. Streetman and S. Banerjee, “Solid state electronic devices”, Prentice Hall (2000).
95.W. J. Li, E. W. Shi, W. Z. Zhong, and Z. W. Yin, J. Cryst. Growth., 203, 186 (1999).
96.http://nano.ksu.edu.tw/files/elearning/RAMAN%20%E5%85%89%E8%AD%9C%E5%8E%9F%E7%90%86%E5%8F%8A%E6%87%89%E7%94%A8.pdf.
97.H. Wang, S. Baek, J. Song, J. Lee, and S. Lim, Nanotechnology, 19, 075607 (2008).
98.J. G. Lu, Z. Z. Ye, Y. J. Zeng, L. P. Zhu, L. Wang, J. Yuan, and B. H. Zhao, J. Appl. Phys., 100, 073714 (2006).
99.M. L. Lee, J. K. Sheu, W. C. Lai, S. J. Chen, Y. K. Su, M. G. Chen, C. J. Kao, G. C. Chi, and J. M. Tsai, Appl. Phys. Lett, 82, 2913 (2003).
100.M. Lampert and P.Mark, “Current Injection in Solids”, Acadamica (1970).
101.A. J. Bard, and L. R. Faulkner, “Electrochemical Methods” Wiley (1980).