臺灣博碩士論文加值系統

此篇論文中，主要藉由低溫水熱法成長金屬修飾氧化鋅奈米結構，並分別應用到紫外光之金屬-半導體-金屬結構感測器和場發射器元件之應用，其中論文主軸可分為三部份，第一部分主要分為二個段落(1) 鎵摻雜氧化鋅奈米片紫外光感測器之研究(2) 不同摻雜鎵濃度於氧化鋅奈米柱紫外光感測器之研究；第二部分為銀奈米粒子修飾氧化鋅奈米柱紫外光感測器之研究；最後為銀奈米粒子修飾氧化鋅奈米柱紫外光場發射元件之研究。
在本文一開始，本章節主要分為二個段落。(1) 藉由低溫水熱法成長垂直排列的鎵摻雜氧化鋅奈米片。鎵摻雜氧化鋅奈米片具有六角纖鋅礦結構及尖銳的表面形態，平均長度和直徑估計為720和26 nm。我們成功製造出鎵摻雜氧化鋅奈米金屬-半導體-金屬紫外光感測器。施加1V偏壓，其紫外光對可見光的拒斥比約為81，元件量測光響應度為2.83 × 10-5 A/W。在低頻雜訊的分析，此光感測器的等效雜訊功率估計為5.92 × 10-9 W，其相對應檢測度2.24 × 109 cm·Hz0.5W−1。(2) 我們利用水熱法於非晶氧化鋅晶種層/玻璃基板上成長氧化鋅奈米柱應用於金屬-半導體-金屬紫外光感測器。施加1V偏壓，不同摻雜鎵濃度於氧化鋅奈米柱分別為0.25、0.5、和1mM，測量元件得到光響應度分別為2.2×10-2、14.9、和14.1 A/W。結果說明改變鎵濃度可用於控制感測器的光響應。此外，在低頻雜訊的分析，測量等效雜訊功率估計分別為1.06 × 10−9， 3.13 × 10−11，和1.29 × 10−10 W,，其相對應檢測度估計分別為1.24 × 1010，4.21 × 1011，和1.01 × 1011 cm·Hz0.5W−1。對比於不同摻雜濃度之氧化鋅奈米柱，鎵(0.5mM)摻雜之氧化鋅奈米柱擁有最佳的光電特性。
論文第二部分，本研究主要是以新穎之水熱法成長銀奈米粒子修飾氧化鋅奈米柱應用於金屬-半導體-金屬紫外光感測器。施加0.2V偏壓，測量感測器元件之光響應度估計為12.4 A/ W，而相應紫外光對可見光的拒斥比約為4478。此外，在低頻雜訊的分析，測量光感測器的等效雜訊功率估計為4.85 × 10−11 W，其相對應檢測度估計為2.72 × 1011 cm·Hz0.5W−1。這樣的結果說明銀奈米粒子修飾氧化鋅奈米柱紫外光感測器有非常好的實用性。
最後，我們成功通過低溫水熱法成長銀奈米粒子修飾氧化鋅奈米柱，並應用到場發射器元件之應用。元件於暗箱和紫外光照射兩種條件量測之下，所得場發射元件具有較低起始電場分別約為3.93和2.04 V/μm，而場增強因子分別約為1,593和57,872，這可以歸咎於能帶彎曲和更多的電子積累在吸附的銀奈米粒子，使得電子可以更容易從銀奈米粒子發射。

In this dissertation, the metal-modified ZnO nanostructures were grown on an a-ZnO seed layer via the low-temperature hydrothermal method (90 °C) and applied to metal semiconductor-metal (MSM) ultraviolet (UV) photodetector (PD) and field emission devices. This dissertation is divided into three parts. In the first part, Ga-doped ZnO nanosheet-based (MSM) ultraviolet (UV) photodetectors are investigated and Ga-doped ZnO nanorods (NRs) with different Ga concentrations are synthesized for application to an MSM UV PD. In the second part, the synthesis of Ag nanoparticle (NP)-decorated ZnO NR MSM UV PDs is discussed. Finally, the third part discusses the synthesis of Ag NP-decorated ZnO NR field emitters under UV illumination.
The beginning of this dissertation is divided into two sections. First, vertical Ga-doped ZnO nanosheets are synthesized on a ZnO-seeded glass substrate via the hydrothermal method at low temperature and used to fabricate a GZO NS MSM UV PD. The average length and average diameter of the interwoven GZO nanosheet was 720 and 26 nm. The measured cutoff wavelength of the PDs was 340 nm when biased at 1 V, and the measured fabricated PD responsivity was 2.85 × 10-5. The corresponding UV-to-visible rejection ratio was approximately 81 when biased at 1 V. The noise equivalent power (NEP) of the fabricated GZO NS MSM PD was 5.92 × 10-9 W, and its specific detectivity was 2.24 × 109 cm • Hz0.5 • W-1. The fabrication of ZnO NRs doped with various Ga concentrations on a ZnO-seed layer/glass substrate via the low temperature hydrothermal method is then presented. Ga-doped ZnO (GZO) NR-based UV PDs were fabricated under a bias of 1 V. The measured device responsitivities of the ZnO NRs doped with 0.25, 0.5, and 1 mM Ga were 2.2 × 10−2, 14.9, and 14.1 A/W, respectively. Varying the Ga concentration allowed control of the responsivity of the fabricated PDs. Under a bandwidth of 1 kHz and applied bias of 1 V, the NEP of the GZO NR PDs with 0.25, 0.5, and 1 mM Ga were 1.06 × 10−9, 3.13 × 10−11, and 1.29 × 10−10 W, respectively, and their corresponding detectivities were 1.24 × 1010, 4.21 × 1011 W, and 1.01 × 1011 cm•Hz0.5•W−1.
In the second part of this dissertation, Ag NP-decorated ZnO NR arrays were synthesized on a ZnO-seeded glass substrate using a novel and simple hydrothermal method. Under an applied bias of 0.2 V and incident light wavelength of 380 nm, a UV PD based on the Ag NP-decorated ZnO NRs showed a high responsivity of 12.4 A W with a corresponding UV-to-visible rejection ratio of 4478. The noise spectrum of the UV PD was obtained using pure 1/f noise, and the NEP of the fabricated Ag NP-decorated ZnO NR MSM PD was found to be 4.85 × 10−11 W; a detectivity of 2.72 × 1011 cm·Hz0.5·W−1 was also observed.
Finally, Ag NP-decorated ZnO NRs were successfully synthesized on a glass substrate via the hydrothermal method at a low temperature of 90 °C and used to fabricate Ag NP-decorated ZnO NR field emission devices. The resulting Ag NP-decorated ZnO NRs of ultra-turn-on field was reduced to approximately 3.93 and 2.04 V/μm in the dark and under UV illumination, respectively, and the corresponding field enhancement factors were 1,593 and 57,872. These results indicate that the enhanced FE of Ag NP-decorated ZnO NRs can be attributed to the effective formation of potential wells on the surfaces of the Ag NPs, which collect electrons by field emission from the Ag NPs to the vacuum level to enhance field emission.

Abstract (in Chinese) I
Abstract (in English) III
Acknowledgement (in Chinese) VI
Contents VII
Table Captions X
Figure Captions XI

CHAPTER 1.Introduction
1.1Background and Motivation of ZnO 1
1.2Techniques for Synthesizing ZnO Nanostructures 4
1.2.1 Hydrothermal Growth Methods of ZnO 4
1.3Theory of Photodetector 5
1.4Theory of Low-Frequency Noise 7
1.5Theory of Field Emission 7
1.6Motivations and Dissertation Organization 10
References 12

CHAPTER 2.Experimental Section
2.1Fabrication of Ga doped ZnO Nanostructures UV Photodetector 30
2.1.1Fabrication of Ga doped ZnO Nanosheets UV Photodetector 30
2.1.2Fabrication of Ga NPs- doped ZnO Nanorods UV Photodetector 31
2.2Fabrication of Ag NPs-Decorated ZnO Nanorods UV Photodetector and Their Application for Field Emitter 32
2.2.1Fabrication of Ag NPs-Decorated ZnO Nanorods UV Photodetector 32
2.2.2Fabrication of Ag NPs-Decorated ZnO Nanorods Field Emitter 34
2.3Measurements and Analysis 35

CHAPTER 3.Ultraviolet Photodetectors Based on Gallium-doped ZnO Nanostructures Arrays
3.1Vertical GZO Nanosheets-based UV Photodetectors 43
3.1.1Introduction 43
3.1.2Experimental Results and Discussion 45
3.1.2.1Material and Structure Analyses 45
3.1.2.2Characteristics of Ga-doped ZnO Nanosheets UV Photodetector 48
3.1.2.3The Low-Frequency Noise Characteristics 50
3.2The Effect of Ga doping Concentration on the Low-Frequency Noise Characteristics and Photoresponse Properties of ZnO Nanorods-Based UV Photodetectors 51
3.2.1Introduction 52
3.2.2Experimental Results and Discussion 53
3.2.2.1Material Analysis and Structure Analysis 53
3.2.2.2Characteristics of Ga doped ZnO Nanorod UV Photodetectors 55
3.2.2.3The Low Frequency Noise Characteristics 58
3.2.3Summary 60
References 62

CHAPTER 4.Noise Properties of Ag Nanoparticle-Decorated ZnO Nanorod UV Photodetectors
4.1Introduction 89
4.2Experimental Results and Discussion 91
4.2.1Material and Structure Analyses 91
4.2.2Characteristics of Ag Nanoparticle-Decorated ZnO Nanorod UV Photodetector 93
4.2.3The Low-Frequency Noise Characteristics of Ag Nanoparticle-Decorated ZnO Nanorods UV Photodetector 94
4.3Summary 96
References 97

CHAPTER 5.Enhanced Field Emission Properties of Ag Nanoparticles-Decorated ZnO Nanorods under Ultraviolet Illumination
5.1Introduction 105
5.2Experimental Results and Discussion 107
5.2.1Material and Structure Analyses 107
5.2.2Characteristics of Ag Nanoparticle-Decorated ZnO Nanorod Field Emitter 109
5.3Summary 112
References 113

CHAPTER 6.Conclusions and Prospects
6.1Conclusions 127
6.2Future prospects 128

Publication List of Chih-Chiang Yang 130

References of Chapter 1
[1]http://www.tf.unikiel.de/matwis/amat/semi_en/kap_5/advanced/t5_1_3.html
[2]O. Akhavan, M. Mehrabian, K. Mirabbaszadeh, and R. Azimirad, “Hydrothermal synthesis of ZnO nanorod arrays for photocatalytic inactivation of bacteria, Nanotechnol., vol. 42, no. 22, pp. 225305, Nov. 21, 2009.
[3]Y. W. Heo, V. Varadarajan, M. Kaufman, K. Kim, D. P. Norton, F. Ren, and P. H. Fleming, “Site-specific growth of Zno nanorods using catalysis-driven molecular-beam epitaxy, Appl. Phys. Lett., vol. 81, no. 16, pp. 3046–3048, Oct. 14, 2002.
[4]S. Kar, A. Dev, and S. Chaudhuri, “Simple Solvothermal Route To Synthesize ZnO Nanosheets, Nanonails, and Well-Aligned Nanorod Arrays, J. Phys. Chem. B, vol. 110, no. 36, pp. 17848-17853, Jul. 18, 2006.
[5]X. J. Feng, L. Feng, M. H. Jin, J. Zhai, L. Jiang, and D. B. Zhu, “Reversible super-hydrophobicity to super-hydrophilicity transition of aligned ZnO nanorod films, J. Am. Chem. Soc., vol. 126, no. 1, pp. 62–63, Jan. 14, 2004.
[6]Y. W. Chen, Y. C. Liu, S. X. Lu, C. S. Xu, C. L. Shao, C. Wang, J. Y. Zhang, Y. M. Lu, D. Z. Shen, and X. W. Fan, “Optical properties of ZnO and ZnO:In nanorods assembled by sol-gel method, J. Chem. Phys., vol. 123, no. 13, pp. 134701-1–134701-5, Oct. 1, 2005.
[7]S. M. Peng, Y. K. Su, L. W. Ji, S. J. Young, C. N. Tsai, W. C. Chao, Z. S. Chen, and C. Z. Wu, “Semitransparent Field-Effect Transistors Based on ZnO Nanowire Networks, IEEE Electron Device Lett., vol. 32, no. 4, pp. 533–535, Apr. 2011.
[8]J. Goldberger, D. J. Sirbuly, M. Law, and P. D. Yang, “ZnO Nanowire Transistors, J. Phys. Chem. B, vol. 109, pp. 9-14, 2005
[9]C. Soci, A. Zhang, B. Xiang, S. A. Dayeh, D. P. R. Aplin, J. Park, X. Y. Bao, Y. H. Lo, and D. Wang, “ZnO Nanowire UV Photodetectors with High Internal Gain, Nano Lett., vol. 7, no. 4, pp.1003−1009, Apr. 2007.
[10]Y. H. Liu, S. J. Young, Member, IEEE, L. W. Ji, and S. J. Chang, “Noise Properties of Mg-Doped ZnO Nanorods Visible-Blind Photosensors, IEEE J. Sel. Top. Quantum Electron., vol. 21, no. 4, pp. 3800405-1–3800405-5, Jul. 2015.
[11]S. Liang, H. Sheng, Y. Liu, Z. Huo, Y. Lu, H. Shen, “ZnO Schottky ultraviolet photodetectors, J. Cryst. Growth, vol. 225, pp. 110−113, 2001.
[12]Y. Liu, C. R. Gorla, S. Liang, N. Emanetoglu, Y. Lu, H. Shen, and M. Wraback, “Ultraviolet detectors based on epitaxial ZnO films grown by MOCVD, J. Electronic Mater., vol. 29, pp. 69−74, 2000.
[13]J. X. Wang, X. W. Sun, Y. Yang, H. Huang, Y. C. Lee, O. K. Tan, L. Vayssieres, “Hydrothermally grown oriented ZnO nanorod arrays for gas sensing applications, Nanotechnology, vol. 17, p. 4995, 2006.
[14]T. J. Hsueh, C. L. Hsu, S. J. Chang, and I. C. Chen, “Laterally grown ZnO nanowire ethanol gas sensors, Sens. Actuator B-Chem., vol. 126, no. 2, pp. 473-477,Oct. 1, 2007.
[15]H. Ahn, J. H. Park, S. B. Kim, S. H. Jee, Y. S. Yoon, and D. J. Kim, “Vertically Aligned ZnO Nanorod Sensor on Flexible Substrate for Ethanol Gas Monitoring, Electrochem. Solid-state Lett., vol. 13, pp. J125-J128, 2010.
[16]W. Y. Chang, Y. C. Lai, T. B. Wu, S. F. Wang, F. Chen, and M. J. Tsai, “Unipolar resistive switching characteristics of ZnO thin films for nonvolatile memory applications, Appl. Phys. Lett., vol. 92, pp. 022110– 3, 2008.
[17]Y. D. Chiang, W. Y. Chang, C. Y. Ho, C. Y. Chen, C. H. Ho, S. J. Lin, T. B. Wu, and J. H. He, “Single-ZnO-nanowire memory, IEEE Trans. Electr. Dev., vol.58, pp. 1735– 1740, 2011.
[18]Q. Zhao, H. Z. Zhang, Y. W. Zhu, S. Q. Feng, X. C. Sun, J. Xu, and D. P. Yu, “Morphological effects on the field emission of ZnO nanorod arrays, Appl. Phys. Lett., vol. 86, pp. 203115-1-203115-3, 2005.
[19]Y. H. Huang, Y. Zhang, L. Liu, S. S. Fan, Y. Wei, and J. He, “Controlled Synthesis and Field Emission Properties of ZnO Nanostructures with Different Morphologies, J. Nanosci. Nanotechnol., vol. 6 pp.787-790, 2006.
[20]Y. H. Huang, Y. Zhang, Y. S. Gu, X. D. Bai, J. J. Qi, Q. L. Liao, and J. Liu, “Field emission of a single in-doped ZnO nanowire, J. Phys. Chem. C, vol. 111, no. 26, pp. 9039−9043, Jul. 5, 2007.
[21]C. Soci, a. Zhang, S. A. Dayeh, D. P. R. Aplin, J. Park, X. Y. Bao, Y. H. Lo, and D. Wang, “ZnO Nanowire UV Photodetectors with High Internal Gain, Nano Lett., vol. 7, no. 4, pp. 1003-1009, Feb. 26 2007.
[22]D. X. Ye, S. Moussa, J. D. Ferguson, A. A. Baski, and M. S. El-Shall, “Highly Efficient Electron Field Emission from Graphene Oxide Sheets Supported by Nickel Nanotip Arrays, Nano Lett., vol. 12, no. 3, pp. 1265−1268, Mar. 2012.
[23]S. J. Chang, B. G. Duan, C. H. Hsiao, C. W. Li, and S. J. Young, “UV Enhanced Emission Performance of Low Temperature Grown Ga-Doped ZnO Nanorods, IEEE Photonics Technol. Lett., vol. 26, no. 1, pp. 66−69, Jan. 1, 2014.
[24]Yu-Cheng Chang “Ni-doped ZnO nanotower arrays with enhanced optical and field emission properties, RSC Adv., vol. 4, no. 9, pp. 56241−56247, 2014.
[25]Sheng-Joue Young, and Yi-Hsing Liu “Enhanced Field Emission Properties of Two-Dimensional ZnO NanosheetsUnder UV illumination, IEEE J. Sel. Top. Quantum Electron., vol. 64, no. 4, pp. 9100304−1−9100304−4, 2014.
[26]Yi-Wei Tseng, Fei-Yi Hung, Truan-Sheng Luia, and Shoou-Jinn Chang “Structural and Raman properties of silver-doped ZnO nanorod arrays using electrically induced crystallization process, Mater Res Bull, vol. 64, pp. 274-278, Apr. 2015.
[27]M. Duta, S. Mihaiu, C. Munteanu, M. Anastasescu, P. Osiceanu, A. Marin, S. Preda, M. Nicolescu, M. Modreanu, M. Zaharescu, and M. Gartner “Properties of In–N codoped p-type ZnO nanorods grown through a two-step chemical route, Appl. Surf. Sci., vol. 344, pp. 196-204, Jul. 30, 2015.
[28]Cheng-Liang Hsu, Yi-Dian Gao, You-Syuan Chen, and Ting-Jen Hsueh, “Vertical p‑Type Cu-Doped ZnO/n-Type ZnO Homojunction Nanowire Based Ultraviolet Photodetector by the Furnace System with Hotwire Assistance, Appl. Mater. Interfaces, vol. 6, no. 6, pp. 4277-4285, Mar. 26, 2014.
[29]S. J. Pearton, D. P. Norton, K. Ip, Y. W. Heo, and T. Steiner, “Recent progress in processing and properties of ZnO, Superlattices Microstruct., vol. 34, pp. 3-32, 2003.
[30]J. Guo, J. Zheng, X. Song, and K. Sun, “Synthesis and conductive properties of Ga-doped ZnO nanosheets by the hydrothermal method, Mater. Lett., vol. 97, pp. 34–6, Apr. 15, 2013.
[31]Yi-Hsing Liu, Sheng-Joue Young, Liang-Wen Ji, and Shoou-Jinn Chang, Fellow, “Ga-Doped ZnO Nanosheet Structure-Based Ultraviolet Photodetector by Low-Temperature Aqueous Solution Method, IEEE Trans. Electron Devices, vol. 62, no. 9, pp. 2924–2927, Sep. 2015.
[32]Sheng-Joue Young, and Yi-Hsing Liu, “Ultraviolet photodetectors with Ga-doped ZnO nanosheets structure, Microelectron. Eng., vol. 148, pp. 14–16, Dec. 2015.
[33]Cheng-Liang Hsu, and Shoou-Jinn Chang “Doped ZnO 1D Nanostructures: Synthesis, Properties, and Photodetector Application, Small, vol. 10, no. 22, pp. 4562–4585, Nov. 2014.
[34]C. L. Hsu, C. W. Su, and T. J. Hsueh , “Enhanced field emission of Al-doped ZnO nanowires grown on a flexible polyimide substrate with UV exposure, RSC Adv., vol. 4, no. 6, pp. 2980–2983, 2014.
[35]M. Hwang, J. H. Choi, Y. H. Kwon, H. K. Cho, S. W. Kim, J. H. Lim, and J. Joo, “Effects of In or Ga doping on the growth behavior and optical properties of ZnO nanorods fabricated by hydrothermal process, Phys. Status Solidi A, vol. 210, no. 8, pp. 1552–1556, 2013.
[36]K. Kinoshtia, T. Okutani, H. Tanaka, T. Hinoki, K. Yazawa, K. Ohmi, and S. Kishida “Opposite bias polarity dependence of resistive switching in n -type Ga-doped-ZnO and p -type NiO thin films, Appl. Phys. Lett., vol. 96, no.14, pp. 143505-1–143505-3, Apr. 5, 2010.
[37]S. S. Shinde, and K. Y. Rajpure “High-performance UV detector based on Ga-doped zinc oxide thin films, Appl. Surf. Sci., vol. 257, no.22, pp. 9595–9599, Sep. 1, 2011.
[38]J. F. Lu, C. X. Xu, J. Dai, J. T. Li, Y. Y. Wang, Y. Lin, and P. L “Improved UV photoresponse of ZnO nanorod arrays by resonant coupling with surface plasmons of Al nanoparticles, Nanoscale, vol. 7, no. 8, pp. 3396-3403, 2015.
[39]R. W. Khan a , P. Y. Uthirakumar, K. B. Bae, S. J. Leem, and I. H. Lee, “Localized surface plasmon enhanced photoluminescence of ZnO nanosheets by Au nanoparticles, Mater. Lett., vol. 163, pp. 8-11, 2016.
[40]S. S. Chen, X. H. Pan, H. P. He, W. Chen, W. Dai, C. Chen, H. H. Zhang, P. Ding, J. Y. Huang, B. Lu, J. G. Lu, and Z. Z. Ye, “60-fold photoluminescence enhancement in Pt nanoparticle-coated ZnO films: role of surface plasmon coupling and conversion of non-radiative recombination, Opt. Lett., vol. 40, no. 12, pp. 2782-2785, 2015.
[41]X. L. Zhang, J. L. Zhao, S. G. Wang, H. T. Dai, and X. W. Sun, “Shape-dependent localized surface plasmon enhanced photocatalytic effect of ZnO nanorods decorated with Ag, Int. J. Hydrogen Energy, vol. 39, no. 16, pp. 8238-8245, May. 2015.
[42]J. D. Hwang, M. J. Lai, H. Z. Chen, and M. C. Kao, “Au-Mediated Surface Plasmon Enhanced Ultraviolet Response of p-Si/n-ZnO Nanorods Photodetectors, IEEE Photonics Technol. Lett., vol. 26, no. 10, pp. 1023–1026, May. 15, 2014.
[43]J. D. Hwang, F. H. Wang, C. Y. Kung, and M. C. Chan, “Using the Surface Plasmon Resonance of Au Nanoparticles to Enhance Ultraviolet Response of ZnO Nanorods-Based Schottky-Barrier Photodetectors, IEEE Trans. Nanotechnol., vol. 14, no. 2, pp. 318-321, Mar. 2015.
[44]Yang Liu, Xianghui Zhang, Jun Su, H1aixia Li, Qi Zhang, and Yihua Gao “Ag nanoparticles@ZnO nanowire composite arrays: an absorption enhanced UV photodetector, Opt. Express, vol. 22, no. 24, pp. 30148-30155, Dec. 1, 2014.
[45]Y. M. Chang, M. L. Lin, T. Y. Lai, H. Y. Lee, C. M Lin, Y. C. S. Wu, and J. Y. Juang, “Field Emission Properties of Gold Nanoparticle-Decorated ZnO Nanopillars, ACS Appl. Mater. Interfaces, vol. 4, no. 12, pp. 6675−6681, Dec. 2012.
[46]S. S. Warule, N. S. Chaudhari, R. T. Khare, J. D. Ambekar, B. B. Kale, and M. A. More, “Single step hydrothermal approach for devising hierarchical Ag–ZnO heterostructures with significant enhancement in field emission performance, CrystEngComm., vol. 15, no. 37, pp. 7475−7483, 2013.
[47]L. Q. Hu, L. A. Ma, H. L. Hu, Y. A. Zhang, and T. L. Guo, “Improving the field emission characteristics of tetrapod-like zinc oxide nanostructures by coating with silver nanowires, Mater. Lett., vol. 150, pp. 93–96, 2015.
[48]C. Ye, Y. Bando, X. Fang, G. Shen, and D. Golberg “Enhanced Field Emission Performance of ZnO Nanorods by Two Alternative Approaches, J. Phys. Chem., vol. 111, no.34, pp. 12673–12676, Aug. 30, 2007.
[49]Sheng-Joue Young, Zheng-Dong Lin, Chih-Hung Hsiao, and Chien-Sheng Huang “Enhanced Carbon Nanotube Field Emitter With Adsorbed Au Nanoparticles, IEEE Trans. Electron Devices, vol. 62, no. 12, pp. 4295–4298, Dec. 2015.
[50]F. Li, b, L. J. Zhang, S. M. Wu, Z. Li, Y. Wang, and X. Q. Liu “Au nanoparticles decorated ZnO nanoarrays with enhanced electron field emission and optical absorption properties, Mater. Lett., vol. 145, pp. 209–211, Apr. 15, 2015.
[51]G. J. Wang, Z. C. Li, M. Y. Li, J. C. Liao, C. H. Chen, S. S. Lv, and C. Q. Shi “Enhanced field-emission of silver nanoparticle-graphene oxide decorated ZnO nanowire arrays, Chem. Chem. Phys., vol. 17, no. 47, pp. 31822–31829, 2015.
[52]Z. D. Lin, Sheng-Joue Young, Chih-Hung Hsiao, Shoou-Jinn Chang, and C. S. Huang “Improved Field Emission Properties of Ag-Decorated Multi-Walled Carbon Nanotubes, IEEE Photonics Technol. Lett., vol. 25, no. 11, pp. 1017–1019, Jun. 2013.
[53]Siou-Yi Lin, Shoou-Jinn Chang, and Ting-Jen Hsueh “ZnO Nanowires Modified with Au Nanoparticles Exhibiting High Field-Emission Performance, ECS J. Solid State Sci. Technol., vol. 2, no. 7, pp. N149–N151, 2013.
[54]C. H. Chen, S. J. Chang, S. P Chang, Y. C. Tsai, I. C. Chen, T. J. Hsueh, and C. L. Hsu “Enhanced field emission of well-aligned ZnO nanowire arrays illuminated by UV, Chem. Phys. Lett., vol. 490, no.4-6, pp. 176–179, Apr. 2010.
[55]W. Lee, M. C. Jeong, M. J. Kim, and J. M. Myoung, “Field emission characteristics of ZnO nanoneedle array cell under ultraviolet irradiation, Phys. Lett. A, vol. 370, no. 3-4, pp. 345-350, Oct. 2007.
[56]Y. H. Liu S. J. Young, L. W. Ji, T. H. Meen, C. H. Hsiao, C. S. Huang, and S. J. Chang, “UV enhanced field emission performance of Mg-doped ZnO nanorods, IEEE Trans. Electron Devices, vol. 61, no. 5, pp. 1541–1545, May 2014.
[57]S. Das, K. Dutta, and A. Pramanik “Morphology control of ZnO with citrate: a time and concentration dependent mechanistic insight, Crystengcomm, vol. 15, no.32, pp. 6349–6358, 2013.
[58]M Niskanen, M Kuisma, O Cramariuc, V Golovanov, T. I. Hukka, N Tkachenko, and T. T. Rantala, “Porphyrin adsorbed on the (01 0) surface of the wurtzite structure of ZnO - conformation induced effects on the electron transfer characteristics, PCCP, vol. 15, no.40, pp. 17408–17418, 2013.
[59]H. K. Sun, M. Luo, W. J. Weng, K. Cheng, P. Y. Du, G. Shen, and G. R. Han “Room-temperature preparation of ZnO nanosheets grown on Si substrates by a seed-layer assisted solution route, Nanotechnology, vol. 19, no. 12, pp. 125603–1–125603–5, Mar. 26, 2008.
[60]Z. K. Zheng, Z. S. Lim, Y Peng, L. You, L. Chen, and J. L. Wang, “General Route to ZnO Nanorod Arrays on Conducting Substrates via Galvanic-cell-based approach, Sci. Rep., vol. 3, pp. 02434–1–17418–5, 2013.
[61]S. F. Wei, J. S. Lian, and H. Wu, “Annealing effect on the photoluminescence properties of ZnO nanorod array prepared by a PLD-assistant wet chemical method, Mater. Charact., vol. 61, no. 11, pp. 1239–1244, Nov. 2010.
[62]D. N. Montenegro, A. Souissi, C. Martinez-Tomas, V. Munoz-Sanjose, and V. Sallet, “Morphology transitions in ZnO nanorods grown by MOCVD, J. Cryst. Growth, vol. 359, pp. 122–128, Nov.15, 2012.
[63]Z. F. Liu, L. E, J. Ya, and Y. Xin, “Growth of ZnO nanorods by aqueous solution method with electrodeposited ZnO seed layers, Appl. Surf. Sci., vol. 255, no. 12, pp. 6415–6420, Apr. 1, 2009.
[64]D. Polsongkram, , P. Chamninok, S. Pukird, L. Chow, O. Lupan, G. Chai, H. Khallaf, S. Park, and A. Schulte, “Effect of synthesis conditions on the growth of ZnO nanorods via hydrothermal method, Physica B, vol. 403, no. 19–22, pp. 3713–3717, Oct. 1, 2008.
[65]L. Schmidt-Mende, and J. L. M. Driscoll, “ZnO–nanostructures, defects, and devices, Mater. Today, vol. 10, pp. 40−48, 2007.
[66]Ming-Yueh Chuang, Hsin-Chieh Yu, Yan-Kuin Sua, Chih-Hung Hsiao, Tsung-Hsien Kao, Chien-Sheng Huang, Yu-Chun Huang, Jeng-Je Tsai, and San-Lein Wu “Density-controlled and seedless growth of laterally bridged ZnO nanorod for UV photodetector applications, Sens. Actuator B-Chem., vol. 202, pp. 810−819,Oct. 2014.
[67]Q. Ahsanulhaq, A. Umar, and Y. B. Hahn, “Growth of aligned ZnO nanorods and nanopencils on ZnO/Si in aqueous solution: growth mechanism and structural and optical properties, Nanatechnol., vol. 18, pp. 115603-1-115603-7, 2007.
[68]S. S. Warule, N. S. Chaudhari, R. T. Khare, J. D. Ambekar, B. B. Kale, and M. A. More, “Single step hydrothermal approach for devising hierarchical Ag–ZnO heterostructures with significant enhancement in field emission performance, CrystEngComm., vol. 15, no. 37, pp. 7475−7483, 2013.
[69]S. J. Chang, B. G. Duan, C. W. Liu ,C. H. Hsiao, S. J. Young, and C. S. Huang “UV Enhanced Indium-Doped ZnO Nanorod Field Emitter, IEEE Trans. Electron Devices, vol. 60, no. 11, pp. 3901−3906, 2013.
[70]R. K. Willardson, E. R. Weber, T. D. Moustakas, and J. I. Pankove, Gallium-Nitride (GaN) II (Vol. 57). Academic Press.,1998
[71]C. H. Hsiao, and Shoou-Jinn Chang “Growth of II-VI Compound Semiconductors and their Optoelectronic Properties, National Cheng Kung University, Jun. 2010.
[72]M. Y. Chuang, and Yan-Kuin Su “Research on Growth Mechanism of Laterally Bridged ZnO Nanostructure and their Optoelectronic Application, National Cheng Kung University, 2014.
[73]Y. H. Liu, S. J. Young, L. W. Ji, and S. J. Chang, “Noise Properties of Mg-Doped ZnO Nanorods Visible-Blind Photosensors, IEEE J. Sel. Top. Quantum Electron., vol. 21, no. 4, pp. 3800405−1−3800405−5, 2015.
[74]M. V. Haartman, and M. Ostling, “Low-frequency noise in advanced MOS devices 47 (Springer, Kista, 2007).
[75]Chung-Wei Liu, and Shoou-Jinn Chang “Optoelectronic and Structure Properties of Diluted Magnetic Semiconductor Based on ZnO Nanorods, Jun. 2008.
[76]T. P. Chen, S. J. Young, S. J. Chang, C. H. Hsiao, L. W. Ji, Y. J. Hsu, and S. L.Wu, “Low-frequency noise characteristics of ZnO nanorods Schottky barrier photodetectors, IEEE Sensors J., vol. 13, no. 6, pp. 2115–2119, Jan. 2013.
[77]W. C. Lai, J. T. Chen, and Y. Y. Yang, “Optoelectrical and low-frequency noise characteristics of flexible ZnO-SiO2 photodetectors with organosilicon buffer layer, Opt. Express, vol. 21, no. 8, pp. 9643–9651, Apr. 2013.
[78]R. H. Fowler, and L. W. Nordheim, “Electron emission in intense field, Proc. R. SOC. A229, pp. 173-181, 1928.
[79]R. E. Burgess, H. Kroemer, and J. M. Honston, “Corrected value of Fowler-Nordheim field emission function v(y) and s(y), Phys. Rev., vol. 90, No. 4, pp. 515-515, 1953.
[80]Yu-Ying Hsu, and Huang-Chung Cheng “Study on the Lateral Field Emission Device Using the Metal Thin Films and Carbon Nanotubes as the Emitter Materials, National Chiao Tung University, 2008.
[81]Rong-Ming Ko, and Shui-Jinn Wang “Study on the Growth Mechanisms of One-Dimensional Tungsten Oxide Nanostructures and Their Applications in Gas Sensors and Field Emitters, National Cheng Kung University, Jun. 2009.
[82]Kao-Chao Lin, and Huang-Chung Cheng “Study on the Field Emission Characteristics of Low-Temperature-Synthesized Carbon Nanotubes and Thin Film Edge Field Emitter, National Chiao Tung University, Jul. 2008.

References of Chapter 3
[1]T. Kong, Y. Chen, Y. P. Ye, K. Zhang, Z. X. Wang, and X. P. Wang, “An amperometric glucose biosensor based on the immobilization of glucose oxidase on the ZnO nanotubes, Sens. Actuators, B, vol. 138, no. 1, pp. 344-350, Jul. 1, 2009.
[2]W. H. Hu, Z. S. Lu, Y. S. Liu, T. Chen, X. Q. Zhou, and C. M. Li, “A portable flow-through fluorescent immunoassay lab-on-a-chip device using ZnO nanorod-decorated glass capillaries, Lab Chip, vol. 13, no. 9, pp. 1797-1802, 2013.
[3]S. J. Chang, B. G. Duan, C. H. Hsiao, S. J. Young, B. C. Wang, T. H. Kao, K. S. Tsai, and S. L. Wu, “Low-Frequency Noise Characteristics of In-Doped ZnO Ultraviolet Photodetectors, IEEE Photon. Technol. Lett., vol. 25, no. 21, pp. 2043-2046, Nov. 1, 2013.
[4]J. Shi, M. B. Starr, H. Xiang, Y. Hara, M. A. Anderson, J. H. Seo, Z. Q. Ma, and X. D. Wang, “Interface Engineering by Piezoelectric Potential in ZnO-Based Photoelectrochemical Anode, Nano Lett., vol. 11, no. 12, pp. 5587-5593, Nov. 16, 2011.
[5]H. Y. Yang , D. I. Son , T. W. Kim, J. M. Lee, and W. I. Park, “Enhancement of the photocurrent in ultraviolet photodetectors fabricated utilizing hybrid polymer-ZnO quantum dot nanocomposites due to an embedded graphene layer, Org. Electron., vol. 11, no. 7, pp. 1313-1317, July. 2010.
[6]C. G. Tian, D. Y. Jiang, B. Z. Li, J. Q. Lin, Y. J. Zhao, W. X. Yuan, J. Z. Zhao, Q. C. Liang, S. Gao, J. h. Hou, and J. M. Qin, “Performance Enhancement of ZnO UV Photodetectors by Surface Plasmons, ACS Appl. Mater. Interfaces., vol. 6, no. 3, pp. 2162-2166, Feb. 12, 2014.
[7]T. Gao, and T. Wang, “Two-Dimensional Single Crystal CdS Nanosheets: Synthesis and Properties, Growth Des., vol. 10, no. 11, pp. 4995-5000, Nov. 2014.
[8]P. A. Hu, L. F. Wang, M. Yoon, J. Zhang, W. Feng, X. N. Wang, Z. Z. Wen, J. C. Idrobo, Y. Miyamoto, D. B. Geohegan, and K. Xiao, “Highly Responsive Ultrathin GaS Nanosheet Photodetectors on Rigid and Flexible Substrates, Nano Lett., vol. 13, no. 4, pp. 1649-1654, Apr. 2013.
[9]P. A. Hu, Z. Z. Wen, L. F. Wang, P. h. Tan, and K. Xiao,“Synthesis of Few-Layer GaSe Nanosheets for High Performance Photodetectors, ACS nano., vol. 6, no. 7, pp. 5988-5994, Jul. 2012.
[10]S. W. Liu, C Li, J. G. Yu, and Q. J. Xiang, “Improved visible-light photocatalytic activity of porous carbon self-doped ZnO nanosheet-assembled flowers, CrystEngComm, vol.13, no. 7, pp. 2533-2541, 2011.
[11]X. Y. Wang, Z. P. Tian, T. Yu, H. M. Tian, J. Y. Zhang, S. K. Yuan, X. B. Zhang, Z. S. Li, and Z. G. Zou, “Effective electron collection in highly (110)-oriented ZnO porous nanosheet framework photoanode, Nanotechnol., vol. 21, no. 16, pp. 065703-1-065703-5, Dec. 13, 2006. [12] J. T. Chen, J. Wang, R. F. Zhuo, D. Yan, J. J. Feng, F. Zhang, and P. X. Yan, Appl. Surf. Sci., 255, 3959 (2009).
[12]J. T. Chen, J. Wang, R. F. Zhuo, D. Yan, J. J. Feng, F. Zhang, and P. X. Yan, “The effect of Al doping on the morphology and optical property of ZnO nanostructures prepared by hydrothermal process, Appl. Surf. Sci., vol. 255, no. 7, pp. 3959-3964, Jan. 15, 2009.
[13]Y. W. Chen, Y. C. Liu, S. X. Lu, C. S. Xu, C. L. Shao, C. Wang, J. Y. Zhang, Y. M. Lu, D. Z. Shen, and X. W. Fan, “Optical properties of ZnO and ZnO : In nanorods assembled by sol-gel method, J. Chem. Phys., vol. 123, no. 13, pp. 134701-1-134701-5, Oct. 1, 2005.
[14]I. C. Yao, D. Y. Lee, T. Y. Tseng, and P. Lin, “Fabrication and resistive switching characteristics of high compact Ga-doped ZnO nanorod thin film devices, Nanotechnol., vol. 24, no. 14, pp. 145201-1-145201-8, Apr. 13,2012.
[15]X. Wang, S. Shen, S. Jin, J. Yang, M. Li, X. Wang, H. Han, and C. Li, “Effects of Zn2+ and Pb2+ dopants on the activity of Ga2O3-based photocatalysts for water splitting, Phys. Chem. Chem. Phys., vol. 15, no. 14, pp. 19380-19386, 2013.
[16]C. H. Hsiao, C. S. Huang, S. J. Young, S. J. Chang, J. J. Guo, C. W. Liu, and T. Y. Yang, “Field-Emission and Photoelectrical Characteristics of Ga-ZnO Nanorods Photodetector, IEEE Trans. Electron Dev., vol. 60, no. 6, pp. 1905-1910, Jun. 2013.
[17]K. Y. Wu, Z. Q. Sun, and J. B. Cui, “Unique Approach toward ZnO Growth with Tunable Properties: Influence of Methanol in an Electrochemical Process, Cryst. Growth Des., vol. 12, pp. 2864-2871, Jun. 2012.
[18]J. Guo, J. Zheng, X. Z. Song, and K. Sun, “Synthesis and conductive properties of Ga-doped ZnO nanosheets by the hydrothermal method, Mater. Lett., vol. 97, pp. 34-36, Apr. 15, 2012.
[19]Q. Ahsanulhaq, A. Umar, and Y. B. Hahn, “Growth of aligned ZnO nanorods and nanopencils on ZnO/Si in aqueous solution: growth mechanism and structural and optical properties, Nanatechnol., vol. 18, no. 11, pp. 115603-1-115603-7, Mar. 21, 2007.
[20]S. K. Lim, S. H. Hong, S. H. Hwang, S. Kim, and H. Park, “Characterization of Ga-doped ZnO Nanorods Synthesized via Microemulsion Method, J. Mater. Sci. Technol., vol. 29, no. 1, pp. 39-43, Jan. 2013.
[21]J. M. Wu, Y. R. Chen, and Y. H. Lin, “Rapidly synthesized ZnO nanowires by ultraviolet decomposition process in ambient air for flexible photodetector, Nanoscale, vol. 3, pp. 1053-1058, 2011.
[22]K. Thirunavukkarasu, and R. Jothiramalingam, “Synthesis and structural characterization of Ga-ZnO nanodisk/nanorods formation by polymer assisted hydrothermal process, Powder Technol., vol. 239, pp. 308-313, May. 2013.
[23]A. B. Djurisic, and Y. H. Leung, “Optical properties of ZnO nanostructures, Small, vol. 2, no. 8-9, pp. 944-961, Aug. 2006.
[24]B. D. Yao, Y. F. Chan, and N. Wang, “Formation of ZnO nanostructures by a simple way of thermal evaporation, Appl. Phys. Lett., vol. 81, no. 4, pp. 757-759, Jul. 2002.
[25]T. P. Rao, and M. C. Santhosh Kumar, “Physical properties of Ga-doped ZnO thin films by spray pyrolysis, J. Alloys Compd., vol. 506, no. 2, pp. 788-793, Sep. 13, 2010.
[26]R. Cusco, E. Alarcon-Llado, J. Ibanez, L. Artus, J. Jimenez, B. G. Wang, and M. J. Callahan, “Temperature dependence of raman scattering in ZnO, Phys. Rev. B, vol. 75, no. 16, pp. 165202-1-165202-11, Apr. 2007.
[27]W. Y. Weng, T. J. Hsueh, S. J. Chang, G. J. Huang, and S. P. Chang, “A Solar-Blind beta-Ga2O3 Nanowire Photodetector, IEEE Photon. Technol. Lett., vol. 22, no. 10, pp. 709-711, May, 15. 2010.
[28]J. M. Wu, and C. H. Kuo, “Ultraviolet photodetectors made from SnO2 nanowires, Thin Solid Films, vol. 517, no. 4, pp. 3870-3873, May, 29. 2009.
[29]W. Y. Weng, S. J. Chang, C. L. Hsu, T. J. Hsueh, and S. P. Chang, “A Lateral ZnO Nanowire Photodetector Prepared on Glass Substrate J. Electrochem. Soc., vol. 157, no. 2, pp. 30-33, 2010.
[30]S. P. Chang, C. Y. Lu, S. J. Chang, Y. Z. Chiou, T. J. Hsueh, C. L. Hsu, “Electrical and Optical Characteristics of UV Photodetector With Interlaced ZnO Nanowires IEEE J. Sel. Top. Quant., vol. 17, no. 4, pp. 990-995, 2011.
[31]S. M. Peng, Y. K. Su, and L. W. Ji, “Characterization of self-assembled ordered ZnO nanowire networks applied to photodetection Microelectron. Eng., vol. 100, pp. 16-19, Dec. 2012.
[32]R. X. Shi, P. Yang, X. B. Dong, C. C. Jia, and J. Li, “Hydrothermal growth of upright-standing ZnO sheet microcrystals, Mater. Sci. Eng., vol. 186, pp. 68-72, Aug. 2014.
[33]C. Soci, A. Zhang, B. Xiang, S. A. Dayeh, D. P. R. Aplin, J. Park, X. Y. Bao, Y. H. Lo, and D. Wang, “ZnO nanowire UV photodetectors with high internal gain, Nano Lett., vol. 7, pp. 1003-1009, Apr. 2007.
[34]A. Bera, and D. Basak, “Carrier relaxation through two-electron process during photoconduction in highly UV sensitive quasi-one-dimensional ZnO nanowires, Appl. Phys. Lett., vol. 93, no. 5, pp. 053102-1-053102-3, Aug. 4 2008.
[35]T. Li, D. J. H. Lambert, A. L. Beck, C. J. Collins, B. Yang, M. M. Wong, U. Chowdhury, and R. D. Dupuis, “Solar-blind AlxGa1-xN-based metal-semiconductor-metal ultraviolet photodetectors, Electron. Lett., vol. 36, no. 18, pp. 1581-1583, Aug. 31 2000.
[36]Q. Chen, J. W. Yang, A. Osinsky, S. Gangopadhyay, B. Lim, M. Z. Anwar, M. A. Khan, D. Kuksenkov, and H. Temkin, “Schottky barrier detectors on GaN for visible-blind ultraviolet detection, Appl. Phys. Lett., vol. 70, no. 17, pp. 2277–2279, Apr. 28 1997.
[37]T. Ma, M. Guo, M. Zhang, Y. j. Zhang, and X. D. Wang, “Density-controlled hydrothermal growth of well-aligned ZnO nanorod arrays, Nanotechnol., vol. 18, no. 3, pp. 035605, 2009.
[38]Y. W. Heo, D. P. Norton, L. C. Tien, Y. Kwon, B. S. Kang, F. Ren, S. J. Pearton, and J. R. LaRoche, “ZnO nanowire growth and devices, Mater. Sci. Eng., R, vol. 47, no. 1-2, pp. 1–47, Dec. 20, 2004.
[39]O. Akhavan, M. Mehrabian, K. Mirabbaszadeh, and R. Azimirad, “Hydrothermal synthesis of ZnO nanorod arrays for photocatalytic inactivation of bacteria, Nanotechnol., vol. 42, no. 22, pp. 225305, Nov. 21, 2009.
[40]E. Galoppini, J. Rochford, H. H. Chen, G. Saraf, Y. C. Lu, A. Hagfeldt, and G. Boschloo, “Fast Electron Transport in Metal Organic Vapor Deposition Grown Dye-sensitized ZnO Nanorod Solar Cells, J. Phys. Chem. B, vol. 110, no. 33, pp. 16159–16161, 2006.
[41]S. Lautenschlaege, S. Eisermann, B. K. Meyer, G. Callsen, M. R. Wagner, and A. Hoffmann, “Nitrogen incorporation in homoepitaxial ZnO CVD epilayers, Phys. Status Solidi RRL, vol. 3, no. 1, pp. 16–18, 2009.
[42]L. Vayssieres, “Growth of arrayed nanorods and nanowires of ZnO from aqueous solutions, Adv. Mater., vol. 15, no. 5, pp. 464–466, 2003.
[43]Z. W. Qiu, X. P. Yang, J. Han, P. Zhang, B. Q. Cao, Z. F. Dai, G. T. Duan, and W. P. Cai, “Sodium-Doped ZnO Nanowires Grown by High-pressure PLD and their Acceptor-Related Optical Properties, J. Am. Ceram. Soc., vol. 97, no. 7, pp. 2177–2184, 2014.
[44]S. J. Chang, B. G. Duan, C. H. Hsiao, S. J. Young, B. C. Wang, T. H. Kao, K. S. Tsai, and S. L. Wu, “Low-Frequency Noise Characteristics of In-Doped ZnO Ultraviolet Photodetectors, IEEE Photon. Technol. Lett., vol. 25, no. 21, pp. 2043–2046, Nov. 1, 2013.
[45]C. S. Prajapati, and P. P. Sahay, “Alcohol-sensing characteristics of spray deposited ZnO nano-particle thin films, Sens. Actuators, B, vol. 160, no. 1, pp. 1043–1049, Dec. 15, 2011.
[46]C. L. Hsu, C. W. Su, and T. J. Hsueh , “Enhanced field emission of Al-doped ZnO nanowires grown on a flexible polyimide substrate with UV exposure, RSC Adv., B, vol. 4, no. 6, pp. 2980–2983, 2014. G. C. Park, S
[47]M. Hwang, J. H. Choi, Y. H. Kwon, H. K. Cho, S. W. Kim, J. H. Lim, and J. Joo, “Effects of In or Ga doping on the growth behavior and optical properties of ZnO nanorods fabricated by hydrothermal process, Phys. Status Solidi A, vol. 210, no. 8, pp. 1552–1556, 2013.
[48]K. Kinoshtia, T. Okutani, H. Tanaka, T. Hinoki, K. Yazawa, K. Ohmi, and S. Kishida “Opposite bias polarity dependence of resistive switching in n -type Ga-doped-ZnO and p -type NiO thin films, Appl. Phys. Lett., vol. 96, no.14, pp. 143505-1–143505-3, Apr. 5, 2010.
[49]S. S. Shinde, and K. Y. Rajpure “High-performance UV detector based on Ga-doped zinc oxide thin films, Appl. Surf. Sci., vol. 257, no.22, pp. 9595–9599, Sep. 1, 2011.
[50]J. Guo, J. Zheng, X. Song, and K. Sun, “Synthesis and conductive properties of Ga-doped ZnO nanosheets by the hydrothermal method, Mater. Lett., vol. 97, pp. 34–6,Apr. 15, 2013.
[51]S. R. Jian, G. J. Chen , S. K. Wang, T. C. Lin, J. S. C. Jang, J. Y. Juang, Y. S. Lai, and J. Y. Tseng, “Rapid thermal annealing effects on the structural and nanomechanical properties of Ga-doped ZnO thin films, Surf. Coat. Technol., vol. 231, pp. 176–179, Sep. 2013.
[52]H. Wang, S. Baek, J. Song, J. Lee, and S. Lim, “Microstructural and optical characteristics of solution-grown Ga-doped ZnO nanorod arrays, Nanotechnol., vol. 19, no. 7, pp. 075607–6, Feb. 20, 2008.
[53]G. C. Park, S. M. Hwang, J. H. Lim and J. Joo, “Growth behavior and electrical performance of Ga-doped ZnO nanorod/p-Si heterojunction diodes prepared using a hydrothermal method, Nanoscale, vol. 6, no. 3, pp. 1840–1847, 2014.
[54]J. Zhang, L. D. Sun, C. S. Liao, and C. H. Yan, “A simple route towards tubular ZnO, Chem. Commun., vol. 3, pp. 262–263, 2002.
[55]W. I. Park, Y. H. Jun, S. W. Jung, and Gyu-Chul Yi, “Excitonic emissions observed in ZnO single crystal nanorods, Appl. Phys. Lett., vol. 82, no. 6, pp. 964–966, Feb. 10, 2003.
[56]Z. K. Tang, G. K. L. Wong, and P. Yu, “Room-temperature ultraviolet laser emission from self-assembled ZnO microcrystallite thin films, Appl. Phys. Lett., vol. 72, no. 25, pp. 3270–3272, 1998.
[57]B. X. Lin, Z. X. Fu, and Y. B. Jia, “Green luminescent center in undoped zinc oxide films deposited on silicon substrates, Appl. Phys. Lett., vol. 79, no. 7, pp. 943–945, Aug. 13, 2001.
[58]R. T. Ginting, C. C. Yap, M. Yahaya, and M. M. Salleh, “Solution-Processed Ga-Doped ZnO Nanorod Arrays as Electron Acceptors in Organic Solar Cells, ACS Appl. Mater. Interfaces, vol. 6, no. 7, pp. 5308–5318, Apr. 9, 2014.
[59]I. C. Yao, D. Y. Lee, T. Y. Tseng, and P. Lin, “Fabrication and resistive switching characteristics of high compact Ga-doped ZnO nanorod thin film devices, Nanotechnol., vol. 24, no. 14, pp. 145201-1–145201-8, Apr. 13, 2012.
[60]S. Y. Bae, C. W. Na, J. H. Kang, and J. Park, “Comparative structure and optical properties of Ga-, In-, and Sn-doped ZnO nanowires synthesized via thermal evaporation, J. Phys. Chem. B, vol. 109, no. 7, pp. 2526–2531, Feb. 24, 2005.
[61]Y. B. Li, F. D. Valle, M. Simonnet, I. Yamada, and J. J. Delaunay, “Competitive surface effects of oxygen and water on UV photoresponse of ZnO nanorods, Appl. Phys. Lett., vol. 94, no. 2, pp. 023110, Jan. 12, 2009.
[62]A. Vasudevan, S. Jung, and T. Ji, Senior, “On the Responsivity of UV Detectors Based on Selectively Grown ZnO Nanorods, IEEE Sens. J., vol. 12, no. 5, pp. 1317–1325, May. 12, 2012.
[63]Y. N. Hea, W. Zhang, S. C. Zhang, X. Kang, W. B. Peng, and Y. L. Xu, “Study of the photoconductive ZnO UV detector based on the electrically floated nanowire array, Sens. Actuators, A, vol. 181, pp. 6–12, Jul. 2012.
[64]B. Yuan, X. J. Zheng, Y. Q. Chen, B. Yang, and T. Zhang, “High photosensitivity and low dark current of photoconductive semiconductor switch based on ZnO single nanobelt, Solid State Electron., vol. 55, no. 1, pp. 49–53, Jan. 2011.
[65]H. F. Duan, H. P. He, L. W. Sun, S. Y. Song, and Z. Z. Ye, “Indium-doped ZnO nanowires with infrequent growth orientation, rough surfaces and low-density surface traps, Nanoscale Res. Lett., vol. 8, pp. 1–6, Nov. 21, 2013.
[66]D. S. Kim, J. P. Richters, R. Scholz, T. Voss, and M. Zacharias, “Modulation of carrier density in ZnO nanowires without impurity doping, Appl. Phys. Lett., vol. 96, no. 12, pp. 123110-6, Mar. 22, 2010.
[67]C. T. Lee, T. S. Lin, and H. Y. Lee, “Mechanisms of Low Noise and High Detectivity of p-GaN/i-ZnO/n-ZnO : Al-Heterostructured Ultraviolet Photodetectors, IEEE Photonics Technol. Lett., vol. 22, no. 15, pp. 1117–1119, Aug. 1, 2010.
[68]W. C. Lai, J. T. Chen, and Y. Y. Yang, “Optoelectrical and low-frequency noise characteristics of flexible ZnO-SiO2 photodetectors with organosilicon buffer layer, Opt. Express, vol. 21, no. 8, pp. 9643–9651, Apr. 2013.
[69]C. W. Liu, S. J. Chang, C. H. Hsiao, K. Y. Lo, T. H. Kao, B. C. Wang, S. J. Young, K. S. Tsai, and S. L. Wu, “Noise Properties of Low-Temperature-Grown Co-Doped ZnO Nanorods as Ultraviolet Photodetectors, IEEE J. Sel. Top. Quantum Electron., vol. 20, no. 6, pp. 3800707, Nov–Dec. 2014.

References of Chapter 4
[1]S. Kar, A. Dev, and S. Chaudhuri, “Simple Solvothermal Route To Synthesize ZnO Nanosheets, Nanonails, and Well-Aligned Nanorod Arrays, J. Phys. Chem. B, vol. 110, no. 36, pp. 17848-17853, Jul. 18, 2006.
[2]O. Akhavan, M. Mehrabian, K. Mirabbaszadeh, and R. Azimirad, “Hydrothermal synthesis of ZnO nanorod arrays for photocatalytic inactivation of bacteria, Nanotechnol., vol. 42, no. 22, pp. 225305, Nov. 21, 2009.
[3]L. W. Ji, S. M. Peng, Y. K. Su, S. J. Young, C. Z. Wu, and W. B. Cheng, “Ultraviolet photodetectors based on selectively grown ZnO nanorod arrays, Appl. Phys. Lett., vol. 94, no. 20, pp. 203106-1–203106-3, 2009.
[4]K. Maeda, M. Sato, I. Niikura, and T. Fukuda, “Growth of 2 inch ZnO bulk single crystal by the hydrothermal method, Semicond. Sci. Technol., vol. 20, no. 4, pp. 49-54, Apr. 2005.
[5]C. Soci, a. Zhang, S. A. Dayeh, D. P. R. Aplin, J. Park, X. Y. Bao, Y. H. Lo, and D. Wang, “ZnO Nanowire UV Photodetectors with High Internal Gain, Nano Lett., vol. 7, no. 4, pp. 1003-1009, Feb. 26 2007.
[6]Y. H. Liu, S. J. Young, Member, IEEE, L. W. Ji, and S. J. Chang, “Noise Properties of Mg-Doped ZnO Nanorods Visible-Blind Photosensors, IEEE J. Sel. Top. Quantum Electron., vol. 21, no. 4, pp. 3800405-1–3800405-5, Jul. 2015.,
[7]J. D. Hwang, M. J. Lai, H. Z. Chen, and M. C. Kao, “Au-Mediated Surface Plasmon Enhanced Ultraviolet Response of p-Si/n-ZnO Nanorods Photodetectors, IEEE Photonics Technol. Lett., vol. 26, no. 10, pp. 1023–1026, May. 15, 2014.
[8]J. D. Hwang, F. H. Wang, C. Y. Kung, and M. C. Chan, “Using the Surface Plasmon Resonance of Au Nanoparticles to Enhance Ultraviolet Response of ZnO Nanorods-Based Schottky-Barrier Photodetectors, IEEE Trans. Nanotechnol., vol. 14, no. 2, pp. 318-321, Mar. 2015.
[9]S. S. Warule, N. S. Chaudhari, R. T. Khare, J. D. Ambekar, B. B. Kale, and M. A. More, “Single step hydrothermal approach for devising hierarchical Ag–ZnO heterostructures with significant enhancement in field emission performance, CrystEngComm., vol. 15, no. 37, pp. 7475−7483, 2013.
[10]L. Su, N Qin, W. Xie, J. H. Fu, and D. H. Bao, “The surface-plasmon-resonance and band bending effects on the photoluminescence enhancement of Ag-decorated ZnO nanorods, J. Appl. Phys., vol. 116, no. 6, pp. 063108-1–063108-8, Aug. 14, 2015.
[11]D. D. Lin, H. Wu, W. Zhang, H. P. Li, and W. Pan, “Enhanced UV photoresponse from heterostructured Ag–ZnO nanowires, Appl. Phys. Lett., vol. 94, no. 17, pp.172103-1−172103-3, Apr. 27, 2009.
[12]X. S. Fu, S.Y. Yao, J. T. Xu, Y Lu, and Y. G. Zheng, “Study on high signal-to-noise ratio (SNR) silicon p-n junction photodetector, Optica Applicata, vol. 36, no. 2-3, pp. 421-428, 2006.
[13]Y. Liu, X. H. Zhang, J. Su, H. X. Li, Q. Zhang, and Y. H. Gao, “Ag nanoparticles@ZnO nanowire composite arrays: an absorption enhanced UV photodetector, Opt. Express, vol. 22, no. 24, pp. 30148–30155,Dec. 1, 2014.
[14]T. P. Chen, S. J. Young, S. J. Chang, C. H. Hsiao, L. W. Ji, Y. J. Hsu, and S. L.Wu, “Low-frequency noise characteristics of ZnO nanorods Schottky barrier photodetectors, IEEE Sensors J., vol. 13, no. 6, pp. 2115–2119, Jan. 2013.
[15]S. J. Chang, K. H. Lee, P. C. Chang, Y. C. Wang, C. L. Yu, C. H. Kuo, and S. L. Wu, “GaN-Based Schottky Barrier Photodetectors With a 12-Pair MgxNy-GaN Buffer Layer, IEEE J Quantum Electron, Vol. 44, No.9-10, pp. 916−921, 2008.

References of Chapter 5
[1]X. J. Feng, L. Feng, M. H. Jin, J. Zhai, L. Jiang, and D. B. Zhu, “Reversible super-hydrophobicity to super-hydrophilicity transition of aligned ZnO nanorod films, J. Am. Chem. Soc., vol. 126, no. 1, pp. 62–63, Jan. 14, 2004.
[2]Y. W. Heo, V. Varadarajan, M. Kaufman, K. Kim, D. P. Norton, F. Ren, and P. H. Fleming, “Site-specific growth of Zno nanorods using catalysis-driven molecular-beam epitaxy, Appl. Phys. Lett., vol. 81, no. 16, pp. 3046–3048, Oct. 14, 2002.
[3]Y. W. Chen, Y. C. Liu, S. X. Lu, C. S. Xu, C. L. Shao, C. Wang, J. Y. Zhang, Y. M. Lu, D. Z. Shen, and X. W. Fan, “Optical properties of ZnO and ZnO:In nanorods assembled by sol-gel method, J. Chem. Phys., vol. 123, no. 13, pp. 134701-1–134701-5, Oct. 1, 2005.
[4]T. Ma, M. Guo, M. Zhang, Y. j. Zhang, and X. D. Wang, “Density-controlled hydrothermal growth of well-aligned ZnO nanorod arrays, Nanotechnol., vol. 18, no. 3, pp. 035605-1– 035605-7, Jan. 24, 2007.
[5]S. F. Wei, J. S. Lian, and H. Wu, “Annealing effect on the photoluminescence properties of ZnO nanorod array prepared by a PLD-assistant wet chemical method, Mater. Charact., vol. 61, no. 11, pp. 1239–1244, Nov. 2010.
[6]D. N. Montenegro, A. Souissi, C. Martinez-Tomas, V. Munoz-Sanjose, and V. Sallet, “Morphology transitions in ZnO nanorods grown by MOCVD, J. Cryst. Growth, vol. 359, pp. 122–128, Nov.15, 2012.
[7]Z. F. Liu, L. E, J. Ya, and Y. Xin, “Growth of ZnO nanorods by aqueous solution method with electrodeposited ZnO seed layers, Appl. Surf. Sci., vol. 255, no. 12, pp. 6415–6420, Apr. 1, 2009.
[8]D. Polsongkram, , P. Chamninok, S. Pukird, L. Chow, O. Lupan, G. Chai, H. Khallaf, S. Park, and A. Schulte, “Effect of synthesis conditions on the growth of ZnO nanorods via hydrothermal method, Physica B, vol. 403, no. 19–22, pp. 3713–3717, Oct. 1, 2008.
[9]Y. L. Tao, M. Fu, , A. L. Zhao, D. W. He, and Y. S. Wang, “The effect of seed layer on morphology of ZnO nanorod arrays grown by hydrothermal method, J. Alloys Compd., vol. 489, no. 1, pp. 99–102, Jan. 7, 2010.
[10]S. W. Chen, and J. M. Wu, “Nucleation mechanisms and their influences on characteristics of ZnO nanorod arrays prepared by a hydrothermal method, Acta Mater., vol. 59, no. 2, pp. 841–847, Jan. 2011.
[11]S. M. Peng, Y. K. Su, L. W. Ji, S. J. Young, C. N. Tsai, W. C. Chao, Z. S. Chen, and C. Z. Wu, “Semitransparent Field-Effect Transistors Based on ZnO Nanowire Networks, IEEE Electron Device Lett., vol. 32, no. 4, pp. 533–535, Apr. 2011.
[12]C. Soci, A. Zhang, B. Xiang, S. A. Dayeh, D. P. R. Aplin, J. Park, X. Y. Bao, Y. H. Lo, and D. Wang, “ZnO Nanowire UV Photodetectors with High Internal Gain, Nano Lett., vol. 7, no. 4, pp.1003−1009, Apr. 2007.
[13]K. Ogata, , H. Dobashi, K. Koike, S. Sasa, M. Inoue, and M. Yano, “Patterned growth of ZnO nanorods and enzyme immobilization toward the fabrication of glucose sensors, Physica E, vol. 42, no. 10, pp. 2880−2883, Sep. 2010.
[14]S. H. Ko, D. Lee, H. W. Kang, K. H. Nam, J. Y. Yeo, S. J. Hong, C. P. Grigoropoulos, and H. J. Sung, “Nanoforest of Hydrothermally Grown Hierarchical ZnO Nanowires for a High Efficiency Dye-Sensitized Solar Cell, Nano Lett., vol. 11, no. 2, pp. 666−671, Feb. 2011.
[15]Q. Zhao, H. Z. Zhang, Y. W. Zhu, S. Q. Feng, X. C. Sun, J. Xu, and D. P. Yu, “Morphological effects on the field emission of ZnO nanorod arrays, Appl. Phys. Lett., vol. 86, no. 20, pp. 203115-1−203115-3, May. 16, 2005.
[16]D. X. Ye, S. Moussa, J. D. Ferguson, A. A. Baski, and M. S. El-Shall, “Highly Efficient Electron Field Emission from Graphene Oxide Sheets Supported by Nickel Nanotip Arrays, Nano Lett., vol. 12, no. 3, pp. 1265−1268, Mar. 2012.
[17]S. J. Chang, B. G. Duan, C. H. Hsiao, C. W. Li, S. J. Young, “UV Enhanced Emission Performance of Low Temperature Grown Ga-Doped ZnO Nanorods, IEEE Photonics Technol. Lett., vol. 26, no. 1, pp. 66−69, Jan. 1, 2014.
[18]Y. H. Huang, Y. Zhang, Y. S. Gu, X. D. Bai, J. J. Qi, Q. L. Liao, and J. Liu, “Field emission of a single in-doped ZnO nanowire, J. Phys. Chem. C, vol. 111, no. 26, pp. 9039−9043, Jul. 5, 2007.
[19]C. L. Hsu, C. W. Su, and T. J. Hsueh, “Enhanced field emission of Al-doped ZnO nanowires grown on a flexible polyimide substrate with UV exposure, RSC Adv., vol. 4, no. 6, pp. 2980−2983, 2014.
[20]L. W. Chang, J. W. Yeh, C. L. Cheng, F.S. Shieu, and H. C. Shih, “Field emission and optical properties of Ga-doped ZnO nanowires synthesized via thermal evaporation, RSC Adv., vol. 4, no. 6, pp. 2980−2983, 2014.
[21]Y. M. Chang, M. L. Lin, T. Y. Lai, H. Y. Lee, C. M Lin, Y. C. S. Wu, and J. Y. Juang, “Field Emission Properties of Gold Nanoparticle-Decorated ZnO Nanopillars, ACS Appl. Mater. Interfaces, vol. 4, no. 12, pp. 6675−6681, Dec. 2012.
[22]S. S. Warule, N. S. Chaudhari, R. T. Khare, J. D. Ambekar, B. B. Kale, and M. A. More, “Single step hydrothermal approach for devising hierarchical Ag–ZnO heterostructures with significant enhancement in field emission performance, CrystEngComm., vol. 15, no. 37, pp. 7475−7483, 2013.
[23]C. Ye, Y. Bando, X. Fang, G. Shen, and D. Golberg “Enhanced Field Emission Performance of ZnO Nanorods by Two Alternative Approaches, J. Phys. Chem., vol. 111, no.34, pp. 12673–12676, Aug. 30, 2007.
[24]C. H. Chen, S. J. Chang, S. P Chang, Y. C. Tsai, I. C. Chen, T. J. Hsueh, C. L. Hsu “Enhanced field emission of well-aligned ZnO nanowire arrays illuminated by UV, Chem. Phys. Lett., vol. 490, no.4-6, pp. 176–179, Apr. 2010.
[25]W. Lee, M. C. Jeong, M. J. Kim, J. M. Myoung, “Field emission characteristics of ZnO nanoneedle array cell under ultraviolet irradiation, Phys. Lett. A, vol. 370, no. 3-4, pp. 345-350, Oct. 2007.
[26]Y. H. Liu S. J. Young, L. W. Ji, T. H. Meen, C. H. Hsiao, C. S. Huang, and S. J. Chang, “UV enhanced field emission performance of Mg-doped ZnO nanorods, IEEE Trans. Electron Devices, vol. 61, no. 5, pp. 1541–1545, May 2014.
[27]W. I. Park, Y. H. Jun, S. W. Jung, and Gyu-Chul Yi, “Excitonic emissions observed in ZnO single crystal nanorods, Appl. Phys. Lett., vol. 82, no. 6, pp. 964–966, Feb. 10, 2003.
[28]L. Su, N. Qin, W. Xie, J. H. Fu, and D. H. Bao, “The surface-plasmon-resonance and band bending effects on the photoluminescence enhancement of Ag-decorated ZnO nanorods, J. Appl. Phys., vol. 116, no. 6, pp. 063108-1–063108-8, Aug. 14, 2014.
[29]W. C. Yen, H. Medina, C. W. Hsu, and Y. L. Chueh, “Conformal graphene coating on high-aspect ratio Si nanorod arrays by a vapor assisted method for field emitter, RSC Adv., vol. 4, no. 51, pp. 27106–27111, 2014.
[30]X. T. Zhou, T. H. Lin, Y. H. Liu, C. X. Wu, X. Y. Zeng, D. Jiang, Y. A. Zhang, and T. L. Guo, “Structural, Optical, and Improved Field-Emission Properties of Tetrapod-Shaped Sn-Doped ZnO Nanostructures Synthesized via Thermal Evaporation, ACS Appl. Mater. Interfaces, vol. 5, no. 20, pp. 10067–10073, Oct, 2013.
[31]T.Y. Tsai, S. J. Chang, W. Y. Weng, S. G. Li, S. Liu, C. L. Hsu, H. T. Hsueh, and T. J. Hsueh, “GaN Nanowire Field Emitters With the Adsorption of Au Nanoparticles, IEEE Electron Device Lett., vol. 34, no. 4, pp.553–555, Apr. 2013.
[32]X. L. Liu, M. Song, S. L. Wang, and Y. H. He, “Structure and field-emission properties of W/WO2.72 heterostructures fabricated by vapor deposition, PHYSICA E., vol. 53, pp. 260-265, Sep, 2013.
[33]J. Z. Song, S. A. Kulinich, J. Yan, Z. G. Li, J. P. He, C. X. Kan, and H. B. Zeng, “Epitaxial ZnO Nanowire-on-Nanoplate Structures as Efficient and Transferable Field Emitters, Adv. Mater., vol. 25, no. 40, pp. 5750–5755, Oct, 2013.
[34]Y. M. Juan, H. T. Hsueh, T. C. Cheng, C. W. Wu, and S. J. Chang, “Electron-Field-Emission Enhancement of CuO Nanowires by UV Illumination, ECS SOLID STATE LETT., vol. 3, no. 3, pp. 30-32, 2014.
[35]T. Y. Zhai, X. S. Fang, Y. S. Bando, Q. Liao, X. J. Xu, H. B. Zeng, Y. Ma, J. N. Yao, and D. Golberg, “Morphology-Dependent Stimulated Emission and Field Emission of Ordered CdS Nanostructure Arrays, ACS Nano., vol. 3, no. 4, pp. 949-959, Apr. 2009.
[36]C. C. Wang, K. W. Wang, and T. P. Perng, “Electron field emission from Fe-doped TiO2 nanotubes, Appl. Phys. Lett., vol. 96, no. 14, pp. 143102-1–143102-3, Apr. 5, 2010.
[37]Z. Q. Wang, J. F. Gong, Y. Su, Y. W. Jiang, and S. G. Yang, “Six-Fold-Symmetrical Hierarchical ZnO Nanostructure Arrays: Synthesis, Characterization, and Field Emission Properties, CRYST. GROWTH DES., vol. 10, no. 6. pp. 2455-2459, Jun. 2010.
[38]H. Huang, C. K. Lim, M. S. Tse, J. Guo, and O. K. Tan, “SnO2 nanorod arrays: low temperature growth, surface modification and field emission properties, Nanoscale., vol. 4, no. 5, pp. 1491-1496, 2012.
[39]X. J. Xu, C. C. Tang, H. B. Zeng, T. Y. Zhai, S. Q. Zhang, H. J. Zhao, Y. Bando, and D. Golberg, “Structural Transformation, Photocatalytic, and Field-Emission Properties of Ridged TiO2 Nanotubes, ACS Appl. Mater. Interfaces., vol. 3, no. 4, pp. 1352-1359, Apr. 2011.
[40]T. P. Chen, S. J. Young, S. J. Chang, C. H. Hsiao, and C. S. Huang, “Field-Emission and Photoelectrical Characteristics of ZnO Nanorods Photodetectors Prepared on Flexible Substrate, J. Electrochem. Soc., vol. 159, no. 5, pp. 153-157, 2012.
[41]Y. H. Zheng, C. Q. Chen, Y. Y. Zhan, X. Y. Lin, Q. Zheng, K. M. Wei, and J. F. Zhu, “Photocatalytic activity of Ag/ZnO heterostructure nanocatalyst: Correlation between structure and property, J. Phys. Chem. C, vol. 112, no. 29, pp. 10773-10777, Jul. 24, 2008.
[42]S. Y. Lin, S. J. Chang, and T. J. Hsueh, “ZnO Nanowires Modified with Au Nanoparticles Exhibiting High Field-Emission Performance, ECS J SOLID STATE SC, vol. 2, no. 7, pp. 149-151, 2013.