在本文中，主要探討以水熱法所成長氧化鋅奈米柱之元件光電特性，所製成之元件有紫外光感測器及場發射元件兩種。其中論文可以分為兩部份：第一部分為氧化鋅奈米柱摻雜鋁之光電特性，並將其應用於紫外光感測器及場發射元件。藉由鋁摻雜，可以提升氧化鋅奈米柱的載子濃度，使得元件特性有所提升。第二部分為藉由不同壓力環境下成長氧化鋅奈米柱將其應用在紫外光感測器，探討成長壓力對氧化鋅奈米柱的影響。
在本文的第一部份中，藉由水熱法成長之垂直結構氧化鋅奈米柱，並藉由調配不同的化學溶液，做出鋁摻雜的氧化鋅奈米柱。鋁摻雜氧化鋅奈米柱呈現六角纖鋅礦結構，並且為單晶結構。在由水熱法合成的鋁摻雜氧化鋅奈米柱應用於紫外光感測器做成的元件分析部分；在一伏的偏壓條件下，鋁摻雜氧化鋅奈米柱其光暗電流比例為1.4×103,光響應值為 181 A/W ，紫外光對可見光拒斥比為1.51×103 ，鋁摻雜氧化鋅奈米柱的等效雜訊功率和檢測度分別為1.17×10-11 W 及 4.03×1012 cm·Hz0.5W−1 。在應用於場發射元件的部分，在未照光的條件下，其起始電場為2.35 V/μm ，場發射增強因子為5708。將元件以紫外光照射後，其起始電場降至1.51 V/μm，場發射增強因子也上升到10173。因為鋁摻雜的關係，造成了載子濃度的上升，使得摻雜氧化鋅奈米柱表現出了良好的特性。
在本文的第二部分中，比較了不同成長壓力下所製成之氧化鋅奈米柱紫外光感測器的光電特性。氧化鋅奈米柱的表面形貌在不同壓力環境下沒有顯著改變。在氧化鋅中有著許多不同的缺陷分佈，藉由光致螢光光譜，得知在較高的成長壓力下有較低的缺陷分佈。在一伏的偏壓下，元件P2之光暗電流比為：216。在響應值及紫外光對可見光拒斥比的部分，其數值分別為：40 A/W及1.58×103。等效雜訊功率及感測度經量測得到為：7.53×10-11 W及6.30×1011cm·Hz0.5W−1 。藉由所量測的光電特性，可以得知在成長壓力較高下所得到的氧化鋅奈米柱，有著較佳的光電特性。

In this thesis, the optoelectronic characteristics of ZnO nanorods grown by hydrothermal method are discussed. There are two different device, one is ultraviolet photodetector, and the other is field emission device. The dissertation can be divided into two parts; the first is the application of ultraviolet photodetector and field emission device based on ZnO nanorods. The performance is enhanced due to use aluminum dopant. The second part is ZnO nanorods ultraviolet photodetector with different growth pressures. The influences of ZnO nanorods with different growth pressure are investigated.
In the first part, the ZnO nanorods are fabricated by hydrothermal growth method. By adding a precursor of aluminum nitrate, the aluminum doped ZnO nanorods are successfully synthesized. Aluminum doped ZnO nanorods have Wutrzite surface morphology. Aluminum doped ZnO nanorods is a single crystal structure. The ultraviolet photodetectors based on aluminum doped ZnO nanorods has photo to dark current ratio of 1.4×103. For a given bias 1V,the responsivity is 181 A/W, and the UV-to-Visible ratio is 1.51×103. The noise Equivalent power and detectivity is 1.17×10-11 W and 4.03×1012 cm·Hz0.5W−1, respectively. Also, the field emission device of aluminum doped ZnO nanorods is developed. Under dark condition, the turn-on electric field is 2.35 V/μm, the field enhancement factor is 5708. With UV illumination, the turn-on electric field is reduced to 2.35 V/μm, and the field enhancement factor is enhanced to 10173. The performances are enhanced because aluminum doping can increase the carrier concentration
In the second part, the characteristics of ZnO nanorods fabricated by hydrothermal growth method with different growth pressure are compared. The ZnO nanorods have similar surface morphology. By photoluminescence spectroscopy, it finds that the ZnO nanorods grown with higher pressure have lower defect density. The photo-to-dark current ratio of ZnO nanorods of sample P2 is 216. For a given bias 1V, the responsivity and UV-to-Visible ratio of P2 sample is 40A/W, and 1.58×103respectively. The noise Equivalent power and detectivity is 7.53×10-11 W, and 6.30×1011cm·Hz0.5W−1, respectively. The ZnO nanorods with higher growth pressure shows better performance.

[1] X. Wang, J. Zhou, J. Song, J. Liu, N. Xu, and Z. L. Wang, "Piezoelectric field effect transistor and nanoforce sensor based on a single ZnO nanowire," Nano letters, vol. 6, pp. 2768-2772, 2006.
[2] 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, p. 022110, 2008.
[3] U. T. Nakate, R. N. Bulakhe, C. D. Lokhande, and S. N. Kale, "Au sensitized ZnO nanorods for enhanced liquefied petroleum gas sensing properties," Appl. Surf. Sci., vol. 371, pp. 224-230, May 2016.
[4] J. Liu, H. W. Huang, H. Zhao, X. T. Yan, S. J. Wu, Y. Li, et al., "Enhanced Gas Sensitivity and Selectivity on Aperture-Controllable 3D Interconnected Macro-Mesoporous ZnO Nanostructures," ACS Appl. Mater. Interfaces, vol. 8, pp. 8583-8590, Apr 2016.
[5] V. Postica, I. Holken, V. Schneider, V. Kaidas, O. Polonskyi, V. Cretu, et al., "Multifunctional device based on ZnO:Fe nanostructured films with enhanced UV and ultra-fast ethanol vapour sensing," Mater. Sci. Semicond. Process, vol. 49, pp. 20-33, Jul 2016.
[6] S. Sharma, B. C. Bayer, V. Skakalova, G. Singh, and C. Periasamy, "Structural, Electrical, and UV Detection Properties of ZnO/Si Heterojunction Diodes," IEEE Trans. Electron Devicess, vol. 63, pp. 1949-1956, May 2016.
[7] L. Sun, Z. Lin, X. Zhou, Y. Zhang, and T. Guo, "Synthesis of Cu-doped ZnO quantum dots and their applications in field emission," J. Alloy. Compd., vol. 671, pp. 473-478, Jun 25 2016.
[8] Z. L. Wang, "Zinc oxide nanostructures: growth, properties and applications," J. Phys.-Condes. Matter, vol. 16, p. R829, 2004.
[9] B. Meyer and D. Marx, "Density-functional study of the structure and stability of ZnO surfaces," Phys. Rev. B, vol. 67, p. 035403, 2003.
[10] W.-J. Li, E.-W. Shi, W.-Z. Zhong, and Z.-W. Yin, "Growth mechanism and growth habit of oxide crystals," J. Cryst. Growth. , vol. 203, pp. 186-196, 1999.
[11] S. T. Pantelides, Deep centers in semiconductors: CRC Press, 1992.
[12] M. Lannoo, Point defects in semiconductors I: theoretical aspects vol. 22: Springer Science & Business Media, 2012.
[13] A. Janotti and C. G. Van de Walle, "New insights into the role of native point defects in ZnO," J. Cryst. Growth vol. 287, pp. 58-65, 2006.
[14] R. A. Yotter and D. M. Wilson, "A review of photodetectors for sensing light-emitting reporters in biological systems," Sensors Journal, IEEE, vol. 3, pp. 288-303, 2003.
[15] F. Omnès, E. Monroy, E. Muñoz, and J.-L. Reverchon, "Wide bandgap UV photodetectors: A short review of devices and applications," in Integrated Optoelectronic Devices 2007, 2007, pp. 64730E-64730E-15.
[16] R. G. Forbes, "Field emission: New theory for the derivation of emission area from a Fowler–Nordheim plot," J. Vac. Sci. Technol. B, vol. 17, pp. 526-533, 1999.
[17] R. G. Forbes and K. L. Jensen, "New results in the theory of Fowler–Nordheim plots and the modelling of hemi-ellipsoidal emitters," Ultramicroscopy, vol. 89, pp. 17-22, 2001.
[18] X. Sun, "Designing efficient field emission into ZnO," SPIE Newsroom, The International Society for Optical Engineering, s. 1C4, 2006.
[19] D. P. Norton, Y. W. Heo, M. P. Ivill, K. Ip, S. J. Pearton, M. F. Chisholm, et al., "ZnO: growth, doping & processing," Materials today, vol. 7, pp. 34-40, 2004.
[20] R. S. Wagner and W. C. Ellis, "Vapor‐liquid‐solid mechanism of single crystal growth," Appl. Phys. Lett. vol. 4, pp. 89-90, 1964.
[21] S. R. Hejazi, H. R. M. Hosseini, and M. S. Ghamsari, "The role of reactants and droplet interfaces on nucleation and growth of ZnO nanorods synthesized by vapor–liquid–solid (VLS) mechanism," J. Alloy. Compd., vol. 455, pp. 353-357, 2008.
[22] J. Y. Li and H. Li, "Physical and Electrical Performance of Vapor–Solid Grown ZnO Straight Nanowires," Nanoscale Res. Lett., vol. 4, pp. 165-168, 2009.
[23] N. Wang, Y. Cai, and R. Q. Zhang, "Growth of nanowires," Materials Science and Engineering: R: Reports, vol. 60, pp. 1-51, 2008.
[24] X. Liu, X. Wu, H. Cao, and R. P. H. Chang, "Growth mechanism and properties of ZnO nanorods synthesized by plasma-enhanced chemical vapor deposition," J. Appl. Phys., vol. 95, pp. 3141-3147, 2004.
[25] K.-S. Kim and H. W. Kim, "Synthesis of ZnO nanorod on bare Si substrate using metal organic chemical vapor deposition," Physica B, vol. 328, pp. 368-371, 2003.
[26] Y. Liu, C. R. Gorla, S. Liang, N. Emanetoglu, Y. Lu, H. Shen, et al., "Ultraviolet detectors based on epitaxial ZnO films grown by MOCVD," J. Electron. Mater., vol. 29, pp. 69-74, 2000.
[27] J.-J. Wu and S.-C. Liu, "Low-temperature growth of well-aligned ZnO nanorods by chemical vapor deposition," Adv. Mater., vol. 14, p. 215, 2002.
[28] J.-J. Wu and S.-C. Liu, "Catalyst-free growth and characterization of ZnO nanorods," J. Phys. Chem. B, vol. 106, pp. 9546-9551, 2002.
[29] L. Wang, X. Zhang, S. Zhao, G. Zhou, Y. Zhou, and J. Qi, "Synthesis of well-aligned ZnO nanowires by simple physical vapor deposition on c-oriented ZnO thin films without catalysts or additives," Appl. Phys. Lett. vol. 86, p. 24108, 2005.
[30] S. C. Lyu, Y. Zhang, C. J. Lee, H. Ruh, and H. J. Lee, "Low-temperature growth of ZnO nanowire array by a simple physical vapor-deposition method," Chem. Mat., vol. 15, pp. 3294-3299, 2003.
[31] Y. Sun, G. M. Fuge, and M. N. R. Ashfold, "Growth mechanisms for ZnO nanorods formed by pulsed laser deposition," Superlattices Microstruct., vol. 39, pp. 33-40, 2006.
[32] S. J. Henley, M. N. R. Ashfold, D. P. Nicholls, P. Wheatley, and D. Cherns, "Controlling the size and alignment of ZnO microrods using ZnO thin film templates deposited by pulsed laser ablation," Appl. Phys. A-Mater. Sci. Process., vol. 79, pp. 1169-1173, 2004.
[33] Y. Sun, G. M. Fuge, and M. N. R. Ashfold, "Growth of aligned ZnO nanorod arrays by catalyst-free pulsed laser deposition methods," Chem. Phys. Lett., vol. 396, pp. 21-26, 2004.
[34] M. A. Vergés, A. Mifsud, and C. J. Serna, "Formation of rod-like zinc oxide microcrystals in homogeneous solutions," J. Chem. Soc.-Faraday Trans., Faraday Transactions, vol. 86, pp. 959-963, 1990.
[35] L. Vayssieres, K. Keis, S.-E. Lindquist, and A. Hagfeldt, "Purpose-built anisotropic metal oxide material: 3D highly oriented microrod array of ZnO," J. Phys. Chem. B, vol. 105, pp. 3350-3352, 2001.
[36] M. Ladanov, M. K. Ram, G. Matthews, and A. Kumar, "Structure and opto-electrochemical properties of ZnO nanowires grown on n-Si substrate," Langmuir, vol. 27, pp. 9012-9017, 2011.
[37] Y. Wu and P. Yang, "Direct observation of vapor-liquid-solid nanowire growth," J. Am. Chem. Soc., vol. 123, pp. 3165-3166, 2001.
[38] Z. L. Wang, "Zinc oxide nanostructures: growth, properties and applications," J. Phys.-Condes. Matter, vol. 16, p. R829, 2004.
[39] A. Sherman, "Chemical vapor deposition for microelectronics: principles, technology, and applications," 1987.
[40] D. M. Mattox, Handbook of Physical Vapor Deposition (PVD) Processing: Elsevier Science, 2010.
[41] C. Pacholski, A. Kornowski, and H. Weller, "Self‐assembly of ZnO: from nanodots to nanorods," Ange te Chemie International Edition, vol. 41, pp. 1188-1191, 2002.
[42] M. H. Huang, S. Mao, H. Feick, H. Yan, Y. Wu, H. Kind, et al., "Room-temperature ultraviolet nanowire nanolasers," science, vol. 292, pp. 1897-1899, 2001.
[43] C. H. Ahn, Y. Y. Kim, D. C. Kim, S. K. Mohanta, and H. K. Cho, "A comparative analysis of deep level emission in ZnO layers deposited by various methods," J. Appl. Phys., vol. 105, p. 13502, 2009.
[44] S. M. Sze and K. K. Ng, Physics of semiconductor devices: John wiley & sons, 2006.
[45] Y. Li, F. Della Valle, M. Simonnet, I. Yamada, and J.-J. Delaunay, "Competitive surface effects of oxygen and water on UV photoresponse of ZnO nanowires," Appl. Phys. Lett. vol. 94, p. 023110, 2009.
[46] E. Wongrat, N. Hongsith, D. Wongratanaphisan, A. Gardchareon, and S. Choopun, "Control of depletion layer width via amount of AuNPs for sensor response enhancement in ZnO nanostructure sensor," Sens. Actuator B-Chem., vol. 171, pp. 230-237, 2012.
[47] T. Li, D. J. H. Lambert, A. L. Beck, C. J. Collins, B. Yang, M. M. Wong, et al., "Solar-blind Al x Ga 1-x N-based metal-semiconductor-metal ultraviolet photodetectors," Electronics Letters, vol. 36, pp. 1581-1583, 2000.
[48] Q. Chen, J. W. Yang, A. Osinsky, S. Gangopadhyay, B. Lim, M. Z. Anwar, et al., "Schottky barrier detectors on GaN for visible-blind ultraviolet detection," Appl. Phys. Lett. vol. 70, pp. 2277-2279, 1997.
[49] 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, pp. 223-227, 2015.
[50] S.-J. Chang, B.-G. Duan, C.-H. Hsiao, S.-J. Young, B.-C. Wang, T.-H. Kao, et al., "Low-Frequency Noise Characteristics of In-Doped ZnO Ultraviolet Photodetectors," IEEE Photonics Technol. Lett., vol. 25, pp. 2043-2046, 2013.
[51] S.-J. Chang, C.-W. Liu, C.-H. Hsiao, K.-Y. Lo, S.-J. Young, T.-H. Kao, et al., "Noise Properties of Fe-ZnO Nanorod Ultraviolet Photodetectors," IEEE Photonics Technol. Lett., vol. 25, pp. 2089-2092, 2013.
[52] C.-C. Yang, Y.-K. Su, M.-Y. Chuang, T.-H. Kao, H.-C. Yu, and C.-H. Hsiao, "The Effect of Ga Doping Concentration on the Low-Frequency Noise Characteristics and Photoresponse Properties of ZnO Nanorods-Based UV Photodetectors," IEEE J. Sel. Top. Quantum Electron., vol. 21, pp. 233-239, 2015.
[53] X. Bai, E. G. Wang, P. Gao, and Z. L. Wang, "Measuring the work function at a nanobelt tip and at a nanoparticle surface," Nano Letters, vol. 3, pp. 1147-1150, 2003.
[54] C.-H. Chen, S.-J. Chang, S.-P. Chang, Y.-C. Tsai, I. C. Chen, T.-J. Hsueh, et al., "Enhanced field emission of well-aligned ZnO nanowire arrays illuminated by UV," Chem. Phys. Lett., vol. 490, pp. 176-179, 2010.
[55] S.-J. Young and Y.-H. Liu, "Enhanced field emission properties of two-dimensional ZnO nanosheets under UV illumination," IEEE J. Sel. Top. Quantum Electron., vol. 21, pp. 427-430, 2015.
[56] Q. Zhao, H. Z. Zhang, Y. W. Zhu, S. Q. Feng, X. C. Sun, J. Xu, et al., "Morphological effects on the field emission of ZnO nanorod arrays," Appl. Phys. Lett. vol. 86, p. 203115, 2005.
[57] U. K. Gautam, L. S. Panchakarla, B. Dierre, X. Fang, Y. Bando, T. Sekiguchi, et al., "Solvothermal Synthesis, Cathodoluminescence, and Field‐Emission Properties of Pure and N‐Doped ZnO Nanobullets," Adv. Funct. Mater., vol. 19, pp. 131-140, 2009.
[58] A. Wei, X. W. Sun, C. X. Xu, Z. L. Dong, M. B. Yu, and W. Huang, "Stable field emission from hydrothermally grown ZnO nanotubes," Appl. Phys. Lett. vol. 88, p. 213102, 2006.
[59] Y. Huang, Y. Zhang, Y. Gu, X. Bai, J. Qi, Q. Liao, et al., "Field emission of a single in-doped ZnO nanowire," J. Phys. Chem. C, vol. 111, pp. 9039-9043, 2007.
[60] Y. H. Liu, S.-J. Young, L. W. Ji, T. H. Meen, C. H. Hsiao, C. S. Huang, et al., "UV enhanced field emission performance of Mg-doped ZnO nanorods," IEEE Trans. Electron Devices, vol. 61, pp. 1541-1545, 2014.
[61] B. P. Zhang, N. T. Binh, K. Wakatsuki, Y. Segawa, Y. Yamada, N. Usami, et al., "Pressure-dependent ZnO nanocrsytal growth in a chemical vapor deposition process," J. Phys. Chem. B, vol. 108, pp. 10899-10902, 2004.
[62] S. Muthukumar, H. Sheng, J. Zhong, Z. Zhang, N. W. Emanetoglu, and Y. Lu, "Selective MOCVD growth of ZnO nanotips," IEEE Trans. Nanotechnol., vol. 2, pp. 50-54, 2003.
[63] D. D. Lee and W. T. Conner, "Hydroxyapatite coatings and a method of their manufacture," ed: Google Patents, 1998.
[64] L. Yingying, C. Chuanwei, D. Xiang, G. Junshan, and Z. Haiqian, "Facile fabrication of UV photodetectors based on ZnO nanorod networks across trenched electrodes," Journal of Semiconductors, vol. 30, p. 063004, 2009.
[65] R. Shabannia, H. A. Hassan, H. Mahmodi, N. Naderi, and H. R. Abd, "ZnO nanorod ultraviolet photodetector on porous silicon substrate," Semiconductor Science and Technology, vol. 28, p. 115007, 2013.
[66] S.-J. Young, Y.-H. Liu, C.-H. Hsiao, S.-J. Chang, B.-C. Wang, T.-H. Kao, et al., "ZnO-based ultraviolet photodetectors with novel nanosheet structures," IEEE Trans. Nanotechnol., vol. 13, pp. 238-244, 2014.