本論文是以磁控濺鍍系統斜向成長 n 型氧化鋅於 p 型氮化鎵二維奈米柱陣列結構，來製作具高載子注入效率與高輻射複合率之氧化鋅/氮化鎵異質接面紫外光發光二極體奈米柱陣列(ZnO/GaN nanorod array LEDs)。藉由氮化鎵奈米柱本身所提供的遮蔽效應(shadowing effect)，斜向氧化鋅濺鍍氣流(glancing ZnO vapor-flows)將選擇性的沉積於氮化鎵奈米柱陣列頂端，並有效地連結整個二維氮化鎵奈米柱，最終形成具奈米尺寸的異質接面(nano-junctions)發光二極體陣列。我們所製作出之氧化鋅/氮化鎵異質接面紫外光發光二極體奈米柱陣列本身具有良好的二極體整流特性和低導通電壓(4.5V)，並在順向電流的操作下可穩定發射主要波長為 λ＝390nm 之偏紫白光發光光譜。其主要可歸因於奈米異質接面結構之高載子注入效率所造成氧化鋅缺陷複合飽和，以及氧化鋅近能隙複合發光效率之提升。更重要的是，本論文所提出的斜向濺鍍氧化鋅方法將可省去在傳統奈米柱結構之鈍化與絕緣過程中，所需涉及聚合物填充或其他複雜之材料生長步驟，大幅地提升元件良率與降低製作成本，並可廣泛地運用於其他具奈米尺寸之光電元件(nano-devices)。

High-efficient ZnO-based nanorod array light-emitting diodes (LEDs) were grown by an oblique-angle deposition scheme. Due to the shadowing effect, the inclined ZnO vapor-flow was selectively deposited on the tip surfaces of pre-fabricated p-GaN nanorod arrays, resulting in the formation of nanosized heterojunctions. The LED architecture composed of the slanted n-ZnO film on p-GaN nanorod arrays exhibits a well-behaving current rectification of junction diode with low turn-on voltage of 4.5 V, and stably emits violetish-white luminescence with dominant peak of 390 nm under the operation of forward injection currents. In general, as the device fabrication does not involve passivation of using a polymer or sophisticated material growth techniques, the revealed scheme might be readily applied on other kinds of nanoscale optoelectronic devices.

[1] A. Tsukazaki, A. Ohtomo, T. Onuma, M. Ohtani, T. Makino, M. Sumiya, K. Ohtani, S. F. Chichibu, S. Fuke, Y. Segawa, H. Ohno, H. Koinuma, and M. Kawasaki, “Repeated temperature modulation epitaxy for p-type doping and light-emitting diode based on ZnO,” Nat. Mater., vol. 4, p. 42, 2005.
[2] D. M. Bagnall, Y. F. Chen, Z. Zhu, T. Yao, M. Y. Shen, and T. Goto, “High temperature excitonic stimulated emission from ZnO epitaxial layers,” Appl. Phys. Lett., vol. 73, p. 1038, 1998.
[3] Z. L. Wang, “Zinc oxide nanostructures: growth, properties and applications,” J. Phys.: Condens. Mat., vol. 16, p. R829, 2004.
[4] M. Joseph, H. Tabata, and T. Kawai, “p-Type Electrical Conduction in ZnO Thin Films by Ga and N Codoping,” Jpn. J. Appl. Phys. Lett., vol. 38, p. L1205, 1999.
[5] C. Y. Huang, Y. J. Lee, T. Y. Lin, S. L. Chang, J. T. Lian, H. M. Lin, N. C. Chen, and Y. J. Yang, “Direct formation of InN-codoped p-ZnO/n-GaN heterojunction diode by solgel spin-coating scheme,” Opt. Lett., vol. 39, p. 805, 2014.
[6] B. Xiang, P. W. Wang, X. Z. Zhang, S. A. Dayeh, D. P. R. Aplin, C. Soci, D. P. Yu, and D. L. Wang, “Rational Synthesis of p-Type Zinc Oxide Nanowire Arrays Using Simple Chemical Vapor Deposition,” Nano Lett., vol. 7, p. 323, 2007.
[7] A. Khan, K. Balakrishnan, and T. Katona, “Ultraviolet light-emitting diodes based on group three nitrides,” Nat. Photon. vol. 2, p. 77, 2008.
[8] Ya. I. Alivov, J. E. Van Nostrand, D. C. Look, M. V. Chukichev, and B. M. Ataev, “Observation of 430 nm electroluminescence from ZnO/GaN heterojunction light-emitting diodes,” Appl. Phys. Lett., vol. 83, p. 2943, 2003.
[9] S. J. An and G. C. Yi, “Near ultraviolet light emitting diode composed of n-GaN/ZnO coaxial nanorod heterostructures on a p-GaN layer,” Appl. Phys. Lett., vol. 91, p. 123109, 2007.
[10] C. Bayram, F. H. Teherani, D. J. Rogers, and M. Razeghi, “A hybrid green light-emitting diode comprised of n-ZnO/(InGaN/GaN) multi-quantum-wells/p-GaN,” Appl. Phys. Lett., vol. 93, p. 081111, 2008.
[11] H. Huang, G. Fang, Y. Li, S. Li, X. Mo, H. Long, H. Wang, D. L. Carroll, and X. Zhao, “Improved and color tunable electroluminescence from n-ZnO/HfO2/p-GaN heterojunction light emitting diodes,” Appl. Phys. Lett., vol. 100, p. 233502, 2012.
[12] X. Y. Liu, C. X. Shan, C. Jiao, S. P. Wang, H. F. Zhao, and D. Z. Shen, “Pure ultraviolet emission from ZnO nanowire-based p-n heterostructures,” Opt. Lett., vol. 39, p. 422 2014.
[13] E. Lai, W. Kim, and P. Yang, “Vertical nanowire array-based light emitting diodes,” Nano Res., vol. 1, p. 123, 2008.
[14] T. Nakayama and M. Murayama, “Electronic structures of hexagonal ZnO/GaN interfaces,” J. Cryst. Growth, vol. 214–215, p. 299, 2000.
[15] W. I. Park and G. C. Yi, “Electroluminescence in n-ZnO Nanorod Arrays Vertically Grown on p-GaN,” Adv. Mater., vol. 16, p. 87, 2004.
[16] H. Kim, Y. Cho, H. Lee, S. Kim, S. R. Ryu, D. Y. Kim, T. W. Kang, and K. S. Chung, “High-Brightness Light Emitting Diodes Using Dislocation-Free Indium Gallium Nitride/Gallium Nitride Multiquantum-Well Nanorod Arrays,” Nano Lett., vol. 4, p. 1059, 2004.
[17] X. W. Sun, J. Z. Huang, J. X. Wang, and Z. Xu, “A ZnO Nanorod Inorganic/Organic Heterostructure Light-Emitting Diode Emitting at 342 nm,” Nano Lett., vol. 8, p. 1219, 2008.
[18] S. Xu, C. Xu, Y. Liu, Y. Hu, R. Yang, Q. Yang, J. H. Ryou, H. J. Kim, Za. Lochner, S. Choi, R. Dupuis, and Z. L. Wang, “Ordered Nanowire Array Blue/Near-UV Light Emitting Diodes,” Adv. Mater., vol. 22, p. 4749, 2010.
[19] H. K. Fu, C. L. Cheng, C. H. Wang, T. Y. Lin, and Y. F. Chen, “Selective Angle Electroluminescence of Light-Emitting Diodes based on Nanostructured ZnO/GaN Heterojunctions,” Adv. Funct. Mater., vol. 19, p. 3471, 2009.
[20] 李亞儒，邱清華，郭浩中，盧廷昌，王興宗，“高效率二維氮化鎵藍光發光二極體陣列”，化合物半導體，第二期，第 8-15頁，2012。
[21] H. L. Hartnagel, A. L. Dawar, A. K. Jain and C. Jagadish, “Semiconducting Transparent Thin Films,” published by Institute of Physics Publication, p. 17, 1995.
[22] D. P. Nortona, Y. W. Heoa, M. P. Ivilla, K. Ipa, S. J. Peartona, M. F. Chisholmb, T. Steinerc, “ZnO- growth, doping & processing,” Mater. Today, vol. 7, p. 34, 2004.
[23] 蔡來福，“以電漿輔助化學氣相沉積法室溫成長氧化鋅薄膜之研究”，國立中央大學光電科學研究所碩士論文，2002。
[24] 張坤榮，“摻雜鋁於氧化鋅透明導電膜之光特性與電特性研究”，國立中央大學光電科學研究所碩士論文，2004。
[25] D. J. Leary, J. O. Barnes, and A. G. Jordan, “Calculation of Carrier Concentration in Polycrystalline Films as a Function of Surface Acceptor State Density: Application for ZnO Gas Sensors,” J. Electrochem. Soc., vol. 129, p. 1382, 1982.
[26] S. Liang, H. Sheng, Y. Liu, Z. Huo, Y. Lu and H. Shen, “ZnO Schottky ultraviolet photodetectors,” J. Crystal Growth, vol. 225, p.110, 2001.
[27] F. S. Hickernell, “Zinc oxide films for acoustoelectric device applications”, IEEE Trans. Sonics Ultrason, vol. SU-32, p. 621, 1985.
[28] S. Basu, A. Dutta, “Modified heterojunction based on zinc oxide thin film for hydrogen gas-sensor application,” Sens. Actuators, vol. B22, p. 83, 1994.
 
[29] M. Wwraback, H. Shen, S. Liang, C. R. Gorla, Y. Lu, “High contrast, ultrafast optically addressed ultraviolet light modulator based upon optical anisotropy in ZnO films grown on R-plane sapphire,” Appl. Phys. Lett., vol.74, p.507, (1999).
[30] Z. K. Tang, G. K. L. Wong, et al., “Room-temperature ultraviolet laser emission from self-assembled ZnO microcrystallite thin films”, Appl. Phys. Lett., vol.72, pp.3270, (1998).
[31] A. Mitra, R. K. Thareja, “Photoluminescence and ultraviolet laser emission from nanocrystalline ZnO thin films,” Journal of Applied Physics, vol. 89, p. 2025, 2001.
[32] N H Alvi, Kamran ul Hasan, Omer Nur and Magnus Willander, “The origin of the red emission in n-ZnO nanotubes/p-GaN white light emitting diodes,” Nanoscale Res. Lett., vol. 6, p. 130, 2011.
[33] A. B. Djurišić, Y. H. Leung, K. H. Tam, Y. F. Hsu, L. Ding, W. K. Ge, Y. C. Zhong, K. S. Wong, W. K. Chan, H. L. Tam, K. W. Cheah, W. M. Kwok and D. L. Phillips “Defect emissions in ZnO nanostructures,” Nanotechnology, vol. 18, p. 095702, 2007.
[34] K. H. Tam, C. K. Cheung, Y. H. Leung, A. B. Djurišić, C. C. Ling, C. D. Beling, S. Fung, W. M. Kwok, W. K. Chan, D. L. Phillips, L. Ding and W. K. Ge, “Defects in ZnO nanorods prepared by a hydrothermal method,” J. Phys. Chem. B, vol. 110, pp. 20865-20871, 2006.
[35] S. H. Jeong, B. S. Kim and B. T. Lee, “Photoluminescence dependence of ZnO films grown on Si(100) by radio-frequency magnetron sputtering on the growth ambient,” Appl. Phys. Lett., vol. 82, pp. 2625-2627, 2003.
[36] F. K. Shan, G. X. Liu, W. J. Lee and B. C. Shin, “The role of oxygen vacancies in epitaxial-deposited ZnO thin films,” J. Appl. Phys., vol. 101, pp. 053106-053108, 2007.
[37] A. B. Djurišić, Y. H. Leung, K. H. Tam, L. Ding, W. K. Ge, H. Y. Chen and S. Gwo, “Green, yellow, and orange defect emission from ZnO nanostructures: Influence of excitation wavelength,” Appl. Phys. Lett., vol. 88, pp. 103107-103103, 2006.
[38] 郭育安，藍永明，“綠能減碳磊晶薄膜製程以提升LED發光效率”，崇越論文，國立臺北科技大學機電整合研究所，2010。
[39] 謝嘉民，賴一凡，林永昌，枋志堯，“光激發螢光量測的原理、架構及應用”，奈米通訊，第十二卷，第二期，第 28-39 頁，2005。
[40] X.T. Zhang, Y.C. Liu, Z.Z. Zhi, J.Y. Zhang, Y.M. Lu, D.Z. Shen, W. Xu, X.W. Fan, X.G. Kong, “Temperature dependence of excitonic luminescence from nanocrystalline ZnO films,” J. Lumin., vol. 99, pp. 149–154, 2002.
[41] M. H. Huang, S. Mao, H. Feick, H. Yan, Y. Wu, H. Kind, E. Weber, R. Russo and P. Yang, “Room−temperature ultraviolet nanowire nanolasers,” Science, vol. 292, pp. 1897−1899, 2001.
 
[42] W. I. Park, D. H. Kim, S.-W. Jung, and Gyu-Chul Yi, “Metalorganic vapor-phase epitaxial growth of vertically well-aligned ZnO nanorods,” Appl. Phys. Lett., vol. 80, p. 4232, 2002.
[43] W. I. Park, Gyu-Chul Yi, J.-W. Kim, and S.-M. Park, “Schottky nanocontacts on ZnO nanorod arrays,” Appl. Phys. Lett., vol. 82, p. 4358, 2003.
[44] W. I. Park and G. C. Yi, “Electroluminescence in n-ZnO Nanorod Arrays Vertically Grown on p-GaN,” Adv. Mater., vol. 16, pp. 87-90, 2004.
[45] E. Lai, W. Kim, P. Yang, “Vertical nanowire array-based light emitting diodes,” Nano Res., vol. 1, pp. 123-128, 2008.
[46] T. G. Knorr and R. W. Hoffman, “Dependence of Geometric Anisotropy in Thin Iron Films,” Physical Review, vol. 113, No. 4, pp. 1039-1046, 1959.
[47] D. O. Smith, “Anisotropy in Permalloy Films,” J. Appl. Phys., vol. 30, pp. 264S-265S, 1959.
[48] K. Robbie, J. C. Sit, and M. J. Brett, “Advanced techniques for glancing angle deposition,” J. Vac. Sci. Technol. B, vol. 16, p. 1115, 1998.
[49] 林麗娟，“Ｘ光繞射原理及其應用”，工業材料，第八十六期，第100-109 頁，1994。
[50] 王威智，“矽基板上之金薄膜經快速熱處理後非線性電導特性”，國立中山大學物理學系研究所碩士論文，2002。
[51] 參考網站:http://www.ledinside.com.tw/knowledge/20120525-21281.html
[52] Hong Xiao 著，羅正中，張鼎張 譯，“半導體製程技術導論”，歐亞書局，2003。
[53] 王智偉，“電感耦合式電漿蝕刻HfAlO金氧半場效電晶體之研究”，國立清華大學工程與系統科學研究所碩士論文，2007。
[54] 郭浩中，賴芳儀，郭守義，“LED原理與應用”，五南圖書出版股份有限公司，2013。
[55] H.W. Huang, C.C. Kao, T.H. Hsueh, C.C. Yu, C.F. Lin, J.T. Chu, H.C. Kuo, S.C. Wang, “Fabrication of GaN-based nanorod light emitting diodes using self-assemble nickel nano-mask and inductively coupled plasma reactive ion etching,” Mater. Sci. Eng. B, vol. 113, pp. 125–129, 2004.