臺灣博碩士論文加值系統

本論文研究主要是以熱蒸鍍法製備單晶二氧化鈦奈米線與奈米柱，二氧化鈦奈米結構材料擁有獨特的電子、光學和機械特性之潛在應用，因此最近幾年有關二氧化鈦奈米結構如:奈米線、奈米柱與奈米粒子被廣泛的研究。本論文所製備之奈米結構材料，其內容涵蓋：二階段熱蒸鍍法合成二氧化鈦奈米線；氮氣混入法進行摻雜氮原子對二氧化鈦奈米線所造成之影響；二氧化鈦界面輔助層合成單晶奈米線以及奈米結構之各項光電性質鑑定。
利用二階段式成長與二氧化鈦輔助層之熱蒸鍍法，二氧化鈦奈米線被成功地合成並且達成選區成長。對於二氧化鈦塊材與奈米線在陰極與光激光之特性光譜上，我們發現二氧化鈦之塊材呈現不發光現象。相反地，二氧化鈦單晶奈米線由於尺寸效應而具有藍位移之發光行為，此乃驗證單晶的特性造就其本質之發光行為。在摻雜氮原子進入二氧化鈦奈米線，吾人發現其光譜產生了紅位移之行為，紅位移現象也驗證了二氧化鈦奈米線之能帶縮小了。經由我們設計的合成方法，奈米線之結晶性質與比表面積均有明顯被改善，因此在光觸媒的應用分析上也顯著被提昇。在高倍率穿透式電子顯微鏡上發現二氧化鈦奈米線屬於單晶結構並延著[110]之熱力穩定方向成長。在利用摻雜金元素之二氧化鈦層，吾人測得二氧化鈦奈米線之電子場發射特性，其起始電場在5.7 V/μm時可得到電流密度10 μA/cm2。
更重要地，對於氣相沉積法合成單晶二氧化鈦奈米線之成長機制在本論文中被徹底探討，對於本論文之研究成果將是值得進一步拓展於奈米元件之應用。

Single crystalline TiO2 nanowires/nanorods were synthesized by radio frequency plasma enhanced physical vapor deposition (PVD). TiO2 nanostructured materials often have unusual electronic, optical and mechanical properties as well as a wide range of potential applications. This study encompasses: two-step thermal evaporation for growing TiO2 nanowires; incorporation of nitrogen (N) to the TiO2 during the growth and substrate effect of the TiO2 for the growth of the TiO2 nanowires; performance characterization in TiO2 nanostructures.
The TiO2 layer and two-step thermal evaporation process were developed to grow the TiO2 nanwires. Accordingly, the selected-area growth of TiO2 nanowires was achieved. Both cathodoluminescence (CL) and photoluminescence (PL) indicated that TiO2 nanowires exhibit a blue shift of the emission peak owing to the size effect. Conversely, bulk TiO2 exhibited no luminescence. The nanowires exhibited luminescence, which was associated with their good crystallinity. The N-doped TiO2 nanowires was shown a red shift effect under CL examined. The red shift demonstrated that doping with nitrogen narrowed the band gap of TiO2 nanowires. The high photocatalytic activity of TiO2 nanowires can be obtained by increasing the specific surface area of nanowires and by improving their crystallinity. The high-resolution transmission electron microscopy (HRTEM) demonstrated that the nanowires are grown along the [110] axis, which is the most thermodynamically stable direction and to form the single crystalline TiO2. The Au-doped TiO2 layer enables to increase the electric conductivity. The electron field-emission properties of TiO2 nanowires are for the first time to be correlated by the Folwer-Nordheim (F-N) theory. A low turn-on field was thus found to be ~ 5.7 V/µm at a current density of 10 μA/cm2.
More importantly, a mechanism of utilizing the vapor phase deposition for the synthesis of single crystalline TiO2 nanowires have been addressed throughout this work. It would be exciting to enlarge the current investigation into the studies of the nanodvice fabrication in the near future.

Content
摘要 i
Abstract ii
Content iv
Figure Captions vii
Table Lists xii
Chapter 1 Introduction 1
1.1 Nanotechnology 2
1.2 Size effect and low dimensional material 5
1.3 Nanostructure materials 7
1.4 Crystal structure of TiO2 (Rutile and Anatase) 11
1.5 Nitrogen dopants effect in TiO2 materials 16
Chapter 2 Literature Review 20
2.1 TiO2 nanostructure material 20
2.2 Motivation 20
2.3 An overview of theory and applications 22
2.3-1 Luminescent properties 22
2.3-2 Photoluminescence (PL) 25
2.3-3 Cathodoluminescence (CL) 26
2.3-4 TiO2 band gap structure 28
2.3-5 Photocatalytic properties in TiO2 material 30
2.3-6 Energy application in TiO2 material 32
2.3-7 Electron field emission properties 34
2. 4 Synthesized principle in TiO2 nanowires 35
2.4-1 Chemical process 35
2.4-2 Physics process 41
Chapter 3 Instrumentation and Characterization 44
3.1 Procedures for synthesizing TiO2 nanostructures 44
3.1-1 Preparing TiO2 nanowires by two-step thermal evaporation 44
3.1-2 In-situ observation of the TiO2 nanorods by two-step thermal evaporation 47
3.1-3 Ti buffer layer assisted growth of single-crystalline TiO2 nanowires 50
3.1-4 Doping TiO2 nanowires with nitrogen 52
3.1-5 Growth of TiO2 nanowires by two-step vaccum pressure 53
3.2 Instrumentation 54
3.2-1 DC sputtering for preparing Ti layer and Au catalyst 54
3.2-2 Radio frequency plasma-enhanced physical vapor deposition 54
3.3 Characterization 56
3.3-1 Thin film XRD diffractometer 56
3.3-2 Field emission scanning electron microscopy (FESEM) 56
3.3-3 Field emission transmission electron microscopy (FETEM) 57
3.3-4 X-ray photoelectron spectroscopy (XPS) 58
3.3-5 Raman spectroscopy 58
3.3-6 Luminescence analyzer 60
3.3-7 Ultraviolet visible (UV-vis) spectrophotometer 60
3.3-8 Field emission property analyses 61
Chapter 4 Results and Discussion 63
4.1 Synthesis of TiO2 nanowires by two-step thermal evaporation 63
4.2 In-situ observation of the TiO2 nanorods by two-step thermal evaporation 67
4.3 CL properties in single-crystalline TiO2 nanowires/nanorods 72
4.4 TiO2 buffer layer assisting growth of TiO2 nanowires 75
4.5 Photoluminescence properties in TiO2 nanowires 81
4.6 The CL properties in nitrogen doped effect of TiO2 nanowires 83
4.7 Comparing the photocatalytic activities of single crystalline rutile TiO2 nanowires and mesoporous anatase paste 86
4.8 The electron field emission property in TiO2 nanowires 94
4.9 Formation mechanism 101
4.9-1 Two-step growth mechanism 102
4.9-2 Two-step vacuum pressure growth mechanism 103
Chapter 5 Summary and Future work 107
5.1 Summary 107
5.2 Future Work 109
Reference 111
Publication List 130
Vita 133




















Figure Captions
Fig. 1.1 Schematic the organization of nanostructure [11] 3
Fig. 1.2 A self-cleaned function of the lotus effect [12] 4
Fig. 1.3 Low dimension material definition [13] 6
Fig. 1.4 SEM image of TiO2 nanotube arrays on silicon substrate, (a) top view and (b) side view of nanotubes with outer diameters of 40nm, heights of ~ 1.5 μm, and average center-to-center tube spacing of ~ 60 nm, (c) top, and (d) oblique views of a hexagonally ordered array of nanotubes with outer diameters of 80 nm, heights of ~ 300 nm, and average center-to-center tube specing of ~100 nm. The inset in (d) shows a side view of the tubes on the substrate [14]. 8
Fig. 1.5 (a) A typical HRTEM image of a single TiO2 nanotubes, and (b) A schematic model for the formation of TiO2 nanotubes [22]. 9
Fig. 1.6 Three polymorphs of TiO2 [34] 12
Fig. 1.7 Octahedra-packing diagram for rutile TiO2 [35] 15
Fig. 1.8 Crystal structure of rutile and anatase. 15
Fig. 1.9 Schematic representation of the 110 surface of titanium dioxide. Titanium atoms are indicated by dark spheres, oxygen atoms by the light spheres. The unit cell measures 6.5 Ǻ along and 2.96 Ǻ along [46]. 15
Fig. 1.10 Mechanistic principles for the degradation of pollutants, Radiative and nonradiative as well as photocorrosion processes are omitted for the soak clarity [50]. 18
Fig. 2.1 Radiative band-to-band recombination in (a) direct gap and (b) indirect gap semiconductor [73] 25
Fig. 2.2 Front–surface photoluminescence analyzer with lenses [74] 26
Fig. 2.3 Illustration CL observed in an electron microscope [75] 28
Fig. 2.4 illusations the energy band (a) insulator, (b) typical semiconductor, and (c) conductor [6]. 29
Fig. 2.5 Band edge position of semiconductor materials [77] 30
Fig. 2.6 Photocatalytic reactions is an efficient photochemical conversion process [79] 32
Fig. 2.7 Showing the operational principle of such a device [58] 33
Fig. 2.8 (a) Preparation process of TiO2 nanotubes. SamplesA and B: samples collected after treatment with 10 M NaOH (aq.) when the conductivities of the supernatant reached 10 mS/cm and 70 µS/cm, respectively. Sample C: collected after addition of HCl, when the conductivity reached 800 µS/cm. Sample D: collected when the conductivity reached ~10 µS/cm. DW = distilled water [87]. 37
Fig. 2.8 (b) TiO2 were formed by rolling up the anatase single-wall of sheet [88]. 38
Fig. 2.9 (a) SEM image of the TiO2 nanowires grown in a 50 nm diameter membrane, and (b) Raman spectra of the untreated and annealed bulk nanowires sample samples. All of the AAO template were removed [89]. 39
Fig. 2.10 TEM images of nanowires and SEM images of AAO template that we used in our experiment. (a) TEM images of 20 nm TiO2 nanowires, (b) TEM images of 10 nm TiO2 nanowires, (c) TEM image of a single TiO2 nanowire with a diameter of about 40 nm and the corresponding selected area diffraction pattern of this nanowire (inset), (d) SEM images of 50 nm AAO template, (e) SEM images of 22 nm AAO template, and (f) SEM images of 12 nm AAO template. The scare bars in D, E, and F are 500 nm [89]. 40
Fig. 2.11 Schematic drawing showing the preparation of an array of TiO2 pillars: (a) imprinting a TiO2 wafer using a SiC mold, (b) array of concave dimples formed on TiO2, and (c) photoetching of the textured TiO2 and the array of TiO2 pillars obtained [90]. 42
Fig. 3.1 Two-step thermal evaporation process flow chart. 46
Fig. 3.2 Schematic diagrams showing: (a) as the first-step, the sample covered with 0.5 g titanium powder at HT zone in the graphite boat, and (b) as the second-step, the new titanium powder 0.5 g and the sample separated to locate at HT zone and LT zone on the graphite boat, respectively. 47
Fig. 3.3 Two-step thermal evaporation process flow chart for growing the nanobricks and nanorods 49
Fig. 3.4 Schematic diagrams: (a) in the first step, the sample is covered with 1 g titanium powder in the HT zone in the graphite boat, and (b) In the second step, 1 g of the new titanium powder and the sample were separated from each other in the HT zone and the low-temperature (LT) zone of the graphite boat, respectively. 49
Fig. 3.5 Schematic diagram for RF heater synthesis system, Ti powder and as-prepared substrate separated from each other to locate the graphite boat in the HT zone and the LT zone. 51
Fig. 3.6 Ti buffer layer assisted growing nanowires process 52
Fig. 3.7 Process flow chart of the two-step vacuum pressure 54
Fig. 3.8 (a) Furnace of RF heater with the vacuum system, (b) sketch for PVD furnace system. 55
Fig. 3.9 FESEM JOEL 7000 57
Fig. 3.10 FETEM JEM-2000FX 58
Fig. 3.11 (a) The Raman spectroscopy (Jobin Yvon T64000), (b) block diagrams of the generic components making up a Raman spectrometer [94]. 59
Fig. 3.12 (a) UV-visible spectrophotometer (HITCHI U-2800), (b) showing the optical system of U-2800 mode. 61
Fig. 3.13 The electron field emission measurement system [95]. 62
Fig. 4.1 FESEM image showing that the sample of TiO2 nanowires were grown on alumina substrate, having diameters in the range of 60-90 nm and lengths of hundreds of nm to 2 µm. 65
Fig. 4.2 Thin film X-ray diffraction pattern revealing that the TiO2 nanowires are composed of rutile phase. The alumina phase is attributed from the substrate. 65
Fig. 4.3 Raman spectrum showing the composition of TiO2 nanowires belonging to the rutile structure. The characteristic modes are located at the position of 143, 240, 447, and 610 cm-1. 66
Fig. 4.4 HRTEM images showing (a) an individual TiO2 nanowire, (b) lattice fringe of the nanowire growing on the [110] direction, (c) the SAD of (110) plane showing the single crystallinity of the nanowire, and (d) the corresponding rutile structures, with a fringes spacing of 0.32 nm. 66
Fig. 4.5 FESEM images of TiO2 nanobrick/nanorods deposited on alumina substrates at various growing times in the two-step process. (a) High surface energy of TiO2 nanoclusters in the first step. (b), (c) and (d) second step of the process, after growing times of 10 minutes, 20 minutes and 40 minutes, respectively. 70
Fig. 4.6 (a) TEM image of an individual TiO2 nanorod with twinning structure (b) Electron diffraction pattern of the nanorod, which is a perfect single crystal with twin parts. The solid and dotted lines have a mirror symmetric relationship with each other. (c) HRTEM reveals a lattice spacing of around 0.32nm. 70
Fig. 4.7 Raman spectra of (a) the TiO2 nanobricks after growing time of 20 minutes, and (b) TiO2 nanorods after growing time of 40 minutes 71
Fig. 4.8 The CL spectra at room temperature resulting from the TiO2 nanowires. The peaks are located at the wavelength 418, 465, 536 and 834 nm. 74
Fig. 4.9 The low-magnification FESEM images indicated that the TiO2 nanowires grew with high aspect ratios over the entire substrate, with lengths of up to 3 µm, (a) with diameters in the range 60-90 nm, and (b) TiO2 nanowires grown on the substrate anisotropically. 76
Fig. 4.10 Thin film X-ray diffraction pattern, revealing that the TiO2 nanowires consisted of the rutile phase. 76
Fig. 4.11 Low-magnification TEM image of the TiO2 rutile showing Au nanoparticles; the black circle area corresponding to the insets (a) and (b). (a) HRTEM image showing the (110) plane, corresponding to the parallel fringe spacing of 0.32 nm, and (b) corresponding selected-area electron diffraction pattern, indicating that the single crystalline nanowire grew in the [110] direction. 80
Fig. 4.12 FESEM image, indicating that the nanowires were not grown successfully on the left side, which is coated with gold as a catalyst and does not have the deposited Ti layer. 80
Fig. 4.13 PL spectra showing an emission peak at approximately 380 nm. 82
Fig. 4.14 The CL spectra, revealing that un-doped TiO2 nanowires (NWs) have an emission peak at ~ 402 nm; N-doped TiO2 nanowires have a peak at ~ 439 nm, and bulk TiO2 has a peak at ~ 534 nm. The 439 nm peak of the N-doped nanowires is a red shift if compared with 402 nm peak of the un-doped nanowires, both nanowire emission peaks indicating a blue shift in contrast to the broad band of bulk TiO2 (534 nm). 85
Fig. 4.15 XPS spectra from N-doped and un-doped spectra; the N 1s peak is associated with N-doping effect. 86
Fig. 4.16 (a) FESEM image showing that the TiO2 nanowire are grown all over the substrate, and (b) the anatase TiO2 paste showing a mesporous morphology. 89
Fig. 4.17 XRD spectrum (a) TiO2 rutile phase nanowires, and (b) TiO2 paste anatase phase. 89
Fig. 4.18 TEM image showing an individual TiO2 nanowires with branch-like, (a) SAD pattern, and (b) lattice image 90
Fig. 4.19 TEM image and SAD pattern showing the polycrystalline nature of the anatase nanoparticles. 90
Fig 4.20 (a) Transmission spectra of the methylene blue solution, and (b) decomposition rate of the methylene blue solution after the photodegradation by rutile nanowires and anatase paste. 93
Fig. 4.21 (a) Oblique view of FESEM image, indicating the nanowires were grown all over the substrate, inset a side image revealing that the TiO2 nanowires were grown on the Au-doped TiO2/Si substrate, and (b) Thin film X-ray diffraction pattern, revealing that the TiO2 nanowires consisted of the rutile phase. 95
Fig. 4.22 (a) TEM image, the Au particles indicating that a VLS mechanism governs the growth of TiO2 nanowires, (b) HRTEM lattice image, and (c) corresponding SAED pattern. 96
Fig. 4.23 Au-doped TiO2 layer of cross-sectional image was obtained by TEM, (a) the high-angle annular dark field STEM image, clearly showing a densely scattered high-Z contrast Au dots; the corresponding EDS mapping of (b) Au, (c) Ti, and(d) Si (substrate). 97
Fig. 4.24 (a) J-E field emission plot from TiO2 nanowires; with the corresponding F-N plot inset, and (b) the phosphor screen showing the spatial distribution of the emission sites for TiO2 nanowires. 101
Fig. 4.25 Au clusters (white dots) are highly scattered on the surface of the TiO2 layer. 105
Fig. 4.26 Au clusters (black spots) are embedded into the polycrystalline TiO2 layer 105
Fig. 4.27 Embedding of Au clusters (a) vacuum pressure at 1 Torr, (b) vacuum pressure at 600 Torr, and (c) TiO2 layer underwent re-crystalline, and Au dots were widely scattered throughout the TiO2 layer. 106































Table Lists
Table 1.1 TiO2 structure data [34] 16
Table 4.1 BET specific surface area resulting from the rutile nanowire and anatase paste of the TiO2. 91

1. G. A. Ozin, “Nanochemistry: Synthesis in diminishing dimensions”, Adv. Mater. 4 612 (1992).
2. A. Thiaville, J. Miltat, “Small is beautiful”, Science, 284 1939 (1999).
3. E. Z. da Silva, F. D. Novaes, A. J. R. da Silva, A. Fazzio, “Theoretical study of the formation, evolution, and breaking of gold nanowires”, Phys. Rev. B, 69 115411 (2004).
4. F. Favier, E. C. Walter, M. P. Zach, T. Benter, R. M. Penner, “Hydrogen sensors and switches from electrodeposited palladium mesowire arrays”, Science 293 2227 (2001).
5. P. Alivisatos, P. F. Barbara, A. W. Castleman, J. Chang, D. A. Dixon, M. L. Kline, G. L. McLendon, J. S. Miller, M. A. Ratner, P. J. Rossky, S. I. Stupp, M. I. Thompson, “From molecules to materials: current trends and future directions”, Adv. Mater. 10 1297 (1998).
6. C. P. Poole. Jr. and F. J. Owens, “Introduction to nanotechnology”, Willy Interscience, p. 114.
7. L. H. Liang, C. M. Shen, X. P. Chen, W. M. Liu and H. J. Gao, “The size-dependent phonon frequency of semiconductor nanocrystals”, J. Phys.: Condens. Matter. 16 267 (2004).
8. T. Takagahara and K. Takeda, “Theory of the quantum confinement effect on excitons in quantum dots of indirect-gap materials”, Phys. Rev. B, 46 15578 (1992).
9. H. S. Nalwa, “Handbook of nanotstucture materials and nanotechnology” Vol. 2, Academic press, New York, 2000.
10. http://www.nano.gov/html/facts/whatIsNano.html, National Nanotechnology Initiative (NNI).
11. R. W. Siegel, E. Hu, D. M. Cox, H. Goronkin, L. Jelinski, C. C. Koch, J. Mendel, M. C. Roco, D. T. Shaw, “Nanostructure and science and technology”, Kluwer Academic Publishers, London, 1999, p. 5.
12. http://lotus-shower.isunet.edu/the_lotus_effect.htm.
13. 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. 51 799 (2002).
14. M. S. Sander, M. J. Côté, W. Gu, B. M. Kile, C. P. Tripp, “Template-assisted fabrication of dense, aligned arrays of titania nanotubes with well-controlled dimensions on substrates”, Adv. Mater. 16 2052 (2004)
15. G. R. Patzke, F. Krumeich, R. Nesper, “Oxidic nanotubes and nanorods - anisotropic modules for a future nanotechnology”, Angew, Chem. Int. Ed. 41 2446 (2002).
16. M. Adachi, Y. Murata, M. Harada, S. Yoshikawa, “Formation of titania nanotubes with high photo-catalytic activity” Chem. Lett. 2000 942 (2000).
17. S. Z. Chu, S. Inoue, K. Wada, D. Li, H. Haneda, S. Awatsu, “Highly porous (TiO2-SiO2-TeO2)/Al2O3/TiO2 composite nanostructures on glass with enhanced photocatalysis fabricated by anodization and sol-gel process” J. Phys. Chem. B 2003 107 (6586).
18. O. K. Varghese, D. W. Gong, M. Paulose, K. G. Ong, E. C. Dickey, C. A. Grimes, “Extreme changes in the electrical resistance of titania nanotubes with hydrogen exposure” Adv. Mater. 15 624 (2003).
19. M. Adachi, Y. Murata, I. Okada, S. Yoshikawa, “Formation of titania nanotubes and applications for dye-sensitized solar cells” J. Electrochem. Soc. 150 G488 (2003)
20. P. Hoyer Langmuir 12 141 (1996).
21. T. Kasuga, M. Hiramatsu, A. Hoson, T. Sekino, and K. Niihara, “Formation of titanium oxide nanotube” Langmuir 14 3160 (1998).
22. Y. Q. Wang, G. Q. Hu, X. F. Duan, H. L. Sun, Q. K. Xue, “Microstructure and formation mechanism of titnium dioxide nanotubes”, Chem. Phys. Lett. 365 427 (2002).
23. L. P. Sung, S. Scierka, M. B. -Anaraki, and D. L. Ho, Mat. Res. Soc. Symp. Proc. Vol. 740, I5.4.1 (2003).
24. K. Terabe, K. Kato, H. Miyazaki, S. Yamaguchi, A. Imai, and Y. Tguchi, “Microstructure and crystallization behavior of TiO2 precursor prepared by the sol-gel method using metal alkoxide,” J. Mater. Sci. 29 1617 (1994).
25. X. Z. Ding, Z. Z. Qi, and Y. Z. He, “Effect of hydrolysis water on the preparation of nanocrystalline titania powders via a sol–gel process,” J. Mater. Sci. Lett. 14 21 (1995).
26. C. C. Koch, “ Nanostructured materials: Processing, Properties and Potential Applications”, William, New York 2002, p. 5.
27. A. E. Nielsen, “ Kinetics of precipitation”, Pergamon press, London, NY (1964).
28. A. G. Walton, “The formation and properties of precipitates”, Robert Krieger Publishing Company, Huntington, NY (reprint edition) (1979).
29. D. Appell, “Wired for success” Nature, 419 553 (2002).
30. R. S. Wagner and W. C. Ellis, “Vapor-Liquid-Solid mechanism of single Crystal growth”, Appl. Phys. Lett. 4 89 (1964).
31. A. M. Morales and C. M. Lieber, “A laser ablation method for the synthesis of crystalline semiconductor nanowires” Science, 279 208 (1998).
32. X. Duan and C. M. Lieber, “General synthesis of compound semiconductor nanowires”, Adv. Mater. 12 298 (2000).
33. I. J. McColm, “Ceramic science for materials technologists”, Leonard Hill, Chapman and Hall, New York. 1983.
34. http://ruby.colorado.edu/~smyth/min/rutile.html Mineral Structure and Property Data.
35. D. C. Cronemeyer “ Electrical and properties of rutile single crystals”, Phy. Rev. 87 876 (1952).
36. H. Tang, F. Lévy, H. Berger, P. E. Schmid, “Urbach tail of anatase TiO2”, Phys. Rev. B, 52 7771 (1995).
37. N. Hosaka, T. Sekiya and S. Kurita, “Excitonic state in anatase TiO2 single crystal”, J. of Luminescence, 72 874 (1997).
38. A. Navrotsky and O. J. Kleppa, “Enthalpy of the anatase-rutile transformation”, J. Amer. Ceram. Soc. p.50.
39. H. Tang, H. Berger, P. E. Schmid and F. Lévy, “Photoluminescence in TiO2 anatase single crystals”, Solid State Commun. 87 847 (1993).
40. F. A. Grant, “Properties of rutile (Titanium Dioxide)”, Rev. Mod. Phys. 31 646 (1959).
41. H. P. R. Frederikse, “Recent studies on rutile (TiO2)”, J. Appl. Phys. 32 2211 (1961).
42. H. Tang, K. Prasad, R. Sanjinès, P. E. Schmid, F. Levy, “Electrical and optical properties of TiO2 anatase thin films”, J. Appl. Phys. 75 2042 (1993).
43. K. M. Glassford, J. R. Chelikowsky, “Structural and electronic properties of titanium dioxide”, Phys. Rev B, 46 1284 (1992).
44. J. Pascual, J. Camassel and M. Mathieu, “Fine structure in the intrinsic absorption edge of TiO2”, Phys. Rev. B, 18 5606 (1978).
45. V. E. Henrich, P.A. Cox, “The surface science of metal oxides”, Cambridge University Press, New York, 1994, p. 47.
46. http://www.physics.leidenuniv.nl/sections/ cm/ip/group/theses/jak/chapter3.pdf
47. Ohno, F. Tanigawa, K. Fujihara, S. Izumi, M. Matsumura, “Photocatalytic oxidation of water by visible light using ruthenium-doped titanium dioxide powder”, J. Photochem. Photobiol. A, 127 107 (1999).
48. A. K. Ghosh, G. P. Maruska, “Photoelectrolysis of water in sunlight with sensitized semiconductor electrodes”, J. Electrochem. Soc. 24 1516 (1977).
49. O. Diwald, T. L. Thompson, T. Zubkov, Ed. G. Goralski, S. D. Walck, and J. T. J. Yates, “Photochemical activity of nitrogen-doped rutile TiO2 (110) in visible light”, J. Phys. Chem. B, 108 6004 (2004).
50. H. Kisch, W. Macyk, “Visible-light photocatalysis by modified titania”, Chemphyschem, 3 399 (2002).
51. R. Asahi, T. Morikawa, T. Ohwaki, K. Aoki, and Y. Taga, “Visible-light photocatalysis in nitrogen-doped titanium oxides”, Science, 293 269 (2001).
52. W. Choi, A. Termin, M. R. Hoffman, “The role of metal ion dopants in quantum-sized TiO2: correlation between photoreactivity and charge carrier recombination dynamics”, J. Phys. Chem. 98 13669 (1994).
53. M. Anpo, “Photocatalysis on titanium oxide catalysts: Approaches in achieving highly efficient reactions and realizing the use of visible light”, Catal. Surv. Jan. 1 169 (1997).
54. S. Sato, “Photocatalytic activity of NOx-doped TiO2 in the visible light region”, Chem. Phys. Lett. 123 126 (1986).
55. http://minerials.er.usgs.gov/minerals/pubs/commodity/titanium/index.htmal#mcs
56. A. Fujishima, K. Honda, “Electrochemical photolysis of water at a semiconductor electrode”, Nature, 238 37 (1972).
57. B. O’Regan, M. Grätzel, “A low-cost, high-efficiency solar cell based on dye-sensitized colloidal TiO2 films”, Nature, 353 737 (1991).
58. M. Gratzel, “Photoelectrochemical cells”, Nature, 414 338 (2001).
59. H. Imai, Y. Takei, K. Shimizu, M. Matsuda, H. Hirashima, “Direct preparation of anatase TiO2 nanotubes in porous alumina membranes”, J. Mater. Chem. 9, 2971 (1999).
60. M. M. Lencka, R. E. Riman, “Thermodynamic modeling of hydrothermal synthesis of ceramic powders”, Chem. Mater. 5 61 (1993).
61. K. Shimizu, H. Imai, H. Hirashima, K. Tsukuma, “Low-temperature synthesis of anatase thin films on glass and organic substrates by direct deposition from aqueous solutions”, Thin Solid Films, 351 220 (1999).
62. H. Imai, M. Matsuda, K. Shimizu, H. Hirashima, N. Negishi, “Preparation of TiO2 fibers with well-organized structures”, J. Mater. Chem. 10 2005 (2000).
63. A. Linsebigler, G. Lu, J. T. Jr. Yates, “Photocatalysis on TiO2 surfaces: principles, Mmechanisms, and selected results”, Chem. Rev. 95 735 (1995).
64. M. R. Hoffmann, S. T. Martin, W. Choi, D. W. Bahnemann, “Environmental applications of semiconductor photocatalysis”, Chem. Rev. 95 69 (1995).
65. G. Dagan, M. Tomkiewicz, “Titanium dioxide aerogels for photocatalytic decontamination of aquatic environments”, J. Phys. Chem. 97 12651 (1993).
66. K. Fukushima, I. Yamada, “Electrical properties of TiO2 films deposited by a reactive-ionized cluster beam”, J. Appl. Phys. 65 619 (1989).
67. M. H. Huang, Y. Wu, H. Feick, N. Tran, E. Weber, P. Yang “Catalytic growth of zinc oxide nanowires by vapor transport”, Adv. Mater. 13 113 (2001).
68. K. Y. Dong, Y. K. Dong, “Novel approach to the fabrication of macroporous polymers and their use as a template for crystalline titania nanorings”, Nano Lett. 3 207 (2003).
69. Y. Lei, L. D. Zhang, G. W. Meng, G. H. Li, X. Y. Zhang, C. H. Liang, W. Chen, S. X. Wang, “Preparation and photoluminescence of highly ordered TiO2 nanowire arrays”, Appl. Phys. Lett. 78 1125 (2001).
70. G. H. Du, Q. Chen, R. C. Che, Z. Y. Yuan, L. M. Peng, “Preparation and structure analysis of titanium oxide nanotubes”, Appl. Phys. Lett. 79 3702 (2001).
71. L. Miao, S. Tanemura, S. Toh, K. Kaneko, M. Tanemura, “Fabrication, characterization and Raman study of anatase-TiO2 nanorods by a heating sol-gel template process”, J. Cryst. Growth, 264 246 (2004).
72. R. A. Swalin, “Thermodynamics of solids”, second edition, John Wiley and Sons, Inc 1972, p. 98.
73. D. R. Vij, N. Singh, “Luminescence and related properties of Ⅱ-Ⅵ Semiconductors”, NOVA Science Publishers, INC. Commack New York, 1998, p. 7.
74. E. W. Williams and R. Hall, “ Luminescence and the light emitting diode”, vol. 13 Pergamon press, Oxford, p.105.
75. H. C. Casey, Jr., and R. H. Kaiser, J. Electrochem. Soc. 114 149 (1967).
76. M. D. Muir and P. R. Grant, Sporopollenin. New York: Academic press 33 287 (1974).
77. A. Hagfeldt, M. Grätzel, “Light-induced redox reactions in nanocrystalline systems” Chem. Rev. 95 49 (1995).
78. C. Kutal, N. Serpone, “Photosensitive metal organic systems: mechanistic principles and applications”, American Chemical Society, Washington D.C. 1993.
79. A. Fujishima, K. Hashimoto and T. Watanabe, “TiO2 photocatalysis fundamentals and applications”, BKC. Inc. p. 80.
80. http://ceenve.calpoly.edu/cota/enve436/projects/TiO2b/TiO2-Organics.html
81. S. Ijima, “Helical microtubules of graphitic carbon”, Nature, 354 56 (1991).
82. J. Zhou, N.-S. Xu, S.- Z. Deng, J. Chen, J.-C. She, Z.-L. Wang, “Large area nanowires arrays of molybedenum and molybedenum oxides synthesis and field emission properties”, Adv. Mater. 15 1835 (2003).
83. C. X. Xu, X. W. Sun, B. J. Chen, “Field emission from gallium-doped zinc oxide nanofiber array”, Appl. Phys. Lett. 84 1540 (2004).
84. H. Qi, C. Wang, J. Liu, “A simple method for the synthesis of highly oriented potassium-doped tungsten oxide nanowires” Adv. Mat. 15 411 (2003).
85. S. H. Luo, Q. Wan, W. L. Liu, M. Zhang, Z. F. Di, S. Y. Wang, Z. T. Song, C. L. Lin, J. Y. Dai, “ Vacuum electron field emission from SnO2 nanowhiskers synthesized by thermal evaporation” Nanotechnology, 15 1424 (2004).
86. N. Serpone, E. Pelizzetti, “Photocatalysis: Fundamentals and application”, Wiley: New York, 1989. p.1.
87. T. Kasuga, M. Hiramatsu, A. Hoson, T. Sekino, K. Niihara, “Titania naotubes prepared by chemical processing”, Adv. Mater. 11 1307 (1999).
88. B. D. Yao, Y. F. Chan, X. Y. Zhang, W. F. Zhang, Z. Y. Yang, N. Wang, “Formation mechanism of TiO2 nanotubes”, Appl. Phys. Lett. 82 281 (2003).
89. Z. Miao, D. Xu, J. Quyang, G. Guo, X. Zhao, Y. Tang, “Electrochemically Induced sol-gel preparation of single-crystalline TiO2 nanowires”, Nano Lett. 2 717 (2002).
90. H. Masuda, K. Kanezawa, M. Nakao, A. Yokoo, T. Tamamura, T. Sugiura, H. Minoura, and K. Nishio, “Ordered arrays of nanopillars formed by photoelectrochemical etching on directly imprinted TiO2 single crystals”, Adv. Mater. 15 159 (2003).
91. S. Yoo, S. A. Akbar, and K. H. Sandhang, “Nanocarving of bulk titania crystals into oriented arrays of single crystal nanofibers”, Adv. Mater. 16 260 (2004).
92. B. H. Park, J. Y. Huang, L. S. Li, and Q. X. Jia, “Role of atomic arrangements at interfaces on the phase control of epitaxial TiO2 films”, Appl. Phys. Lett. 80 1174 (2002).
93. L. Miao, S. Tanemura, H. Watanabe, Y. Mori, K. Kaneko, and S. Toh, “The improvement of optical reactivity for TiO2 thin films by N2–H2 plasma surface-treatment”, J. Crystal Growth, 260 118 (2004).
94. L. R. Lewis, H. G. M. Edwards, “ Handbook of raman spectroscopy”, Marcel Dekker, New York, p. 43.
95. 曾永寬 博士論文 “氧化鋅奈米線的合成與特性探討”, 國立清華大學材料科學研究所 2003.
96. JCPDS Card No. 21-1276 (Joint Committee on Powder Diffraction Standards, International Center for Diffraction Data, Swarthmore, PA, 1996: Rutile TiO2).
97. V. A. Skryshevskyy, Th. Dittrich, J. Rappich, “Infrared - active defects in a TiO2 mixture of coexisting anatase and rutile phases”, Phys. Stat. Sol. (a) 201 157 (2004).
98. H. Chang, P. J. Huang, “Thermo-Raman studies on anatase and rutile”, J. Raman. Spectrosc. 29 97 (1998).
99. S. P. S. Porto, P. A. Fleury and T. C. Damen, Phys. Rev. 154 522 (1967).
100. M. Gotic , M. Ivanda, S. Popovic , S. Music, A. Sekulic , A. Turkovic and K. Furic, “Investigation of nanosized Raman TiO2”, J. Raman spectroscopy, 28 555 (1997).
101. Y. Hara and M. Nicol, Phys. Status Solidi, 94 317 (1979).
102. W. F. Zhang, Y. L. He, M. S. Zhang, Z. Yin and Q. Chen, “Raman scattering study on anatase TiO2 nanocrystals” J. Phys. D: Appl. Phys. 33 912 (2000).
103. L. V. Saraf, S. I. Patil, S. B. Ogale, S. R. Sainkar, S. T. Kshirsager, “Synthesis of nanophase TiO2 by ion beam sputtering and cold condensation technique” Int. J. Mod. Phys. B, 12 2635 (1998).
104. R. Plugaru, A. Cremads, and J. Piqueras, “The effect of annealing in different atmospheres on the luminescence of polycrystalline TiO2”, J. Phy.: Condens. Matter. 16 S261 (2004).
105. F. X. Liu, M. Tang, L. Liu, S. Lu, J. Y. Wang, Z. Y. Chen, R. Ji , “Enhanced optical properties of Ag-TiO2 (Rutile) hybrid nanopowder”, Phys. Stat. Sol. (a) 179 437 (2000).
106. M. Anpo, N. Aikawa, Y. Kubokawa, M. Che, C. Louis, E. Giamello, “Photoluminescence and photocatalytic activity of highly dispersed titanium oxide anchored onto porous Vycor glass”, J. Phys. Chem. 89 5017 (1985).
107. S. I. Seok, M. S. Kim, T. S. Suh, “Photoluminescence probing of the formation of titanium dioxide sols from a titanium peroxide solution”, J. Am. Ceram. Soc. 85 1888 (2002).
108. J. M. Wu, H. C. Shih, W. T. Wu, Y. K. Tseng, I .C. Chen “The Thermal evaporation growth and the luminescence property of TiO2 nanowires” J. Cryst. Growth, 281 381 (2005).
109. Y. N. Xia, P. Yang, Y. Sun, Y. Wu, B. Mayers, B. Gates, Y. Yin, F. Kim, and H. Yan, “One-dimensional nanostructures: synthesis, characterization, and applications”, Adv. Mater. 15 353 (2003).
110. R. S. Wagner and W. C. Ellis, “Vapor-Liquid-Solid mechanism of single crystal growth”, Appl. Phys. Lett. 4 89 (1964).
111. E. I. Givargizov, “Fundamental aspects of VLS growth”, J. Cryst. Growth, 31 20 (1975).
112. A. K. Jena and M. C. Chaturvedi, “Phase transformation in materials”, Prentice-Hall New Jersey, 1992, p. 34.
113. J. –P. Borel, “Size effect on the melting temperature of gold particles”, Phys. Rev. A, 13 2287 (1976).
114. J. M. Wu, W. T. Wu, H. C. Shih, “Characterization of Single Crystalline TiO2 Nanowires Grown by Thermal Evaporation” J. Electrochem. Soc, 152 G613 (2005).
115. Y. Jin, G. Li, Yo. Zhang, Yu. Zhang, and L. Zhang, “Photoluminescence of anatase TiO2 thin films achieved by the addition of ZnFe2O4”, J. Phy.: Condens. Matter. 13 L913 (2001).
116. N. Daude, C. Gout, and C. Jouanin “Electronic band structure of titanium dioxide”, Phys. Rev. B 15 3229 (1977).
117. H. Tang, H. B erger, P. E. Schmid, and F. Lévy, “Photoluminescence in TiO2 anatase single crystals”, Solid State Commun. 87 847 (1993).
118. L. G. J. de Haart and G. Blasse, “The observation of exciton emission from rutile single crystals”, J. Solid State Chem. 61 135 (1986).
119. A. K. Ghosh, F. G. Wakim, and R. R. Addiss, JR. “Photoelectronic processes in rutile”, Phys. Rev. 184 979 (1969).
120. I. Fernández, A Cremades, and J. Piqueras, “Cathodoluminescence study of defects in deformed (110) and (100) surfaces of TiO2 single crystals”, Semicond. Sci. Technol. 20 239 (2005).
121. S. D. Mo and W. Y. Ching “Electronic and optical properties of three phases of titanium dioxide: Rutile, anatase, and brookite”, Phys. Rev. B. 51 13023 (1995).
122. L. Grabner, S. E. Stokowski, and W. S. Brower, Jr. “No-Phonon 4T2g-4A2g Transitions of Cr3+ in TiO2”, Phys. Rev. B, 2 590 (1970).
123. M. Mrowetz, W. Balcerski, A. J. Colussi, and M. R. Hoffmann, “Oxidative power of nitrogen-doped TiO2 photocatalysts under visible illumination”, J. Phys. Chem. B, 108 17269 (2004).
124. J. L. Gole, J. D. Stout, C. Burda, Y. Lou, X. Chen, “Highly efficient formation of visible light tunable TiO2-xNx photocatalysts and their transformation at the nanoscale”, J. Phys. Chem. B, 108 1230 (2004).
125. B. Ohtani, M. Kakimoto, S. Nishimoto, and T. Kagiya, “Photocatalytic Reaction of Neat Alcohols by Metal-Loaded Titanium (IV) Oxide Particles,” J. Photochem. Photobiol., A, 70 265 (1993).
126. J. Augustynski, “The role of the surface intermediates in the photoelectrochemical behaviour of anatase and rutile TiO2”, Electrochem. Acta. 38 43 (1993).
127. K. E. Karakitsou and X. E. Verykios, “Effects of altervalent cation doping of titania on its performance as a photocatalyst for water cleavage”, J. Phys. Chem. 97 1184 (1993).
128. Z. Ding, G. Lu, P. Greenfield, “Role of the crystallite phase of TiO2 in heterogeneous photocatalysis for phenol oxidation in water”, J. Phys. Chem. B, 104 4815 (2000).
129. J. Sun, L. Gao,and Q. Zhang, “Synthesizing and comparing the photocatalytic properties of high surface area rutile and anatase titania nanoparticles”, J. Am. Ceram. Soc. 86 1677 (2003).
130. S. Yin, Y. Inoue, S. Uchida, Y. Fujishiro and T. Sato, “Crystallization of titania in liquid media and photochemical properties of crystallized titania”, J. Mater. Res. 13 844 (1998).
131. S. Yin and T. Sato, “Synthesis and photocatalytic properties of fibrous titania prepared from protonic layered tetratitanate precursor in supercritical alcohols”, Ind. Eng. Chem. Res. 39 4526 (2000).
132. S. Yin, H. Hasegawa, D. Maeda, M. Ishitsuka. T. Sato, “Synthesis of visible-light-active nanosize rutile titania photocatalyst by low temperature dissolution–reprecipitation process”, J. photochemistry and photobiology A: Chem. 163 1 (2004).
133. P. Wang, S. M. Zakeeruddin, P. Comte, R. Charvet, R. Humphry-Baker, M. Grätzel, “Enhance the performance of dye-sensitized solar cells by co-grafting amphiphilic sensitizer and hexadecylmalonic acid on TiO2 nanocrystals”, J. Phys. Chem. B, 107 14336 (2003).
134. W. Huang, X. Tang, Y. Wang, Y. Koltypin, A. Gedanken, “Selective synthesis of anatase and rutile via ultrasound irradiation”, Chem. Commun. 15 1415 (2000).
135. Z. Zhang, C. C. Wang, R. Zakaria, J. Y. Ying, “Role of particle size in nanocrystalline TiO2-based photocatalysts”, J. Phys. Chem. B, 102 10871 (1998).
136. R. H. Fowler, L. W. Nordheim. “Electron emission in intense electric fields”, Proc. R. Soc. London, A 119 173 (1928).
137. H. Araki, T. Katayama, and K. Yoshino, “Field emission from aligned carbon nanotubes prepared by thermal chemical vapor deposition of Fe-phthalocyanine”, Appl. Phys. Lett. 79 2636 (2001).
138. H. Jia, Y. Zhang, X. Chen, J. Shu, X. Luo, Z. Zhang, “Efficient field emission from single crystalline indium oxide pyramids”, Appl. Phys. Lett. 82 4146 (2003).
139. M. Sveningsson, R.-E. Morjan, O. A. Nerushev, Y. Sato, J. Bäckström, E. E. B. Campbell, F. Rohmund, “Raman spectroscopy and field-emission properties of CVD-grown carbon-nanotube films”, Appl. Phys. A, 73 409 (2001).
140. S. Dimitrijevic, J. C. Withers, V. P. Mammana, O. R. Monteiro, J. W. Ager, and I. G. Brown, “Electron emission from films of carbon nanotubes and ta-C coated nanotubes”, Appl. Phys. Lett. 75 2680 (1999).
141. P. G. Collins, A. Zettl. “Unique characteristics of cold cathode carbon-nanotube-matrix field emitters”, Phys. Rev. B 55 9391 (1997).
142. X. Xu, G.R. Brandes, “A method for fabricating large-area, patterned, carbon nanotube field emitters”, Appl. Phys. Lett. 74 2549 (1999).
143. M. L. Knotek, P. J. Feibelman, “Ion deposition by core-hole Auger decay”, Phys. Rev. Lett. 40 964 (1978) reference therein.
144. Q. Wan, K. Yu, T. H. Wang, C. L. Lin, “Low-field electron emission from tetrapod-like ZnO nanostructures synthesized by rapid evaporation”, Appl. Phys. Lett. 83 2253 (2003).
145. D. Temple, Mater. “Recent Progress in field emitter array development for high performance applications”, Sci. Eng. R. 24 185 (1999).
146. J.-M. Bonard, J.-P. Salvetat, T. Stöckli, W. A. de Heer, L. Forró , A. Châtelain, “Field-emission from single carbon nanotubes films”, Appl. Phys. Letts. 73 918 (1998).
147. L. H. Chen, K. H. Hong, D. Q. Xiao, W. J. Hsieh, S. H. Lai, H. C. Shih, T. C. Lin, F. S. Shieu, K. J. Chen, H. C. Cheng, “Role of extrinsic atoms on the morphology and field emission properties of carbon nanotubes”, Appl. Phys. Lett. 82 4334 (2003).
148. J. S. Lee, K. S. Liu, F. Y. Chuang, C. Y. Sun, C. M. Huang, I. N. Lin, “Effect of Au buffer on the field emission characteristics of chemical vapor deposited diamond films” Appl. Sur. Sci. 113/114 264 (1997).
149. Y. K. Tseng, H. C. Hsu, W. F. Hsieh, K. S. Liu and I. C. Chen “Two-step oxygen injection process for growth ZnO nanorods” J. Mater. Res. 18 2837 (2003).
150. Z. R. Dai, Z. W. Pan, Z. L. Wang, “Novel nanostructures of functional oxides synthesized by thermal evaporation”, Adv. Funct. Mater. 13 9 (2003).
151. P. Buffat and J. -P. Borel, “Size effect on the melting temperature of gold particles”, Phys. Rev. A, 13 2287 (1976).