數位時代的來臨使我們生活更加便利，而我們追求便利的背後，其代價並不便宜。現今科技對於電及石化燃料的需求日益增加，燃煤發電及石化燃料的使用製造了數十億噸的溫室氣體，PM2.5等空氣汙染使的氣喘、過敏及肺腺癌患者增加，溫室氣體也使全球平均溫度持續升高。本論文研究的方向就是利用半導體電解水的方式將光能轉換成乾淨的氫能，氫能可以達到發電、交通運輸及環境保護等優點，我們使用氮化鎵半導體作為基板，結合表面電漿效應及佈植技術來進行光電化學分解水。
表面電漿效應方面，使用退火的方式製作出銀奈米粒子，電磁輻射通過銀奈米粒子時，粒子中的電子受交流電場的驅動在粒子表面產生振盪，若電磁輻射的波長接近銀粒子的共振波長，會因侷域性表面電漿共振而在特定波長有很大的光吸收，實驗中我們在可見光與紫外光波段都觀察到了光吸收的現象，也確實會提升氮化鎵的光電化學反應。我們比較能隙、折射率、電阻值差異極大的介電質(TiO2、SiO2)濺鍍於奈米銀粒子的效應，並分析元件的光學特性、電性以及光電化學特性。
佈植方面，我們使用佈植矽進入未摻雜的氮化鎵，使其轉變成N型氮化鎵，經過矽佈植的區域在載子濃度及電阻率都得到改善，佈植區就像導線一樣可以將光生載子快速傳輸到外部電路進行光電化學反應。透過結合侷域化表面電漿光吸收的特性與佈植區導線的特性，以兩種效應的優勢使光電化學反應達到更高的增益，實驗中以不同交會比例的佈植區與侷域性表面電漿區來觀察光電流的趨勢，預期能在光電流、氫氣與甲酸產率、轉換效率上獲得提升。

Our research is about solar water splitting with a semiconductor photoelectrode and a metal counter electrode. In order to conduct the reaction of hydrogen producing, the band edge positions of photoelectrode must cover the oxidation and reduction potentials of water. Gallium nitride just meets the condition of hydrogen producing. Nevertheless, Gallium nitride only extracts the energy of ultraviolet owing to energy band gap. In order to solve the problem, we use metal nanoparticles to achieve localized surface plasma resonant (LSPR) effect that absorbing visible light energy. We adopt silver nanoparticles capped with silicon dioxide on gallium nitride substrate. The experiment results reveal an enhancement on photo current. On the other hand, we also apply implant technology in our research. After implanting silicon into gallium nitride, the implanted area forming metal line effect that fast transfer the carrier to carry out hydrogen production reaction. Last, we combine the plasma effect increasing light absorption and ion implantation forming metal line effect to conduct experiment and discuss the production rate and conversion efficiency of hydrogen and formic acid.

[1]K. Zweibel, J. Mason and V. Fthenakis, “By 2050 solar power could end U.S. dependence on foreign oil and slash greenhouse gas emissions,” Sci. Am., 298, pp. 64-73, 2008.
[2]A. Fujishima and K. Honda, “Electrochemical photolysis of water at a semiconductor electrode,” Nature, vol. 238, pp. 37-38, 1972.
[3]M. Pelaez, N. T. Nolan, S. C. Pillai, M. K. Seery, P. Falaras, A. G. Kontos, P. S. M. Dunlop, J. W. J. Hamilton, J. A. Byrne, K. O'Shea, M. H. Entezari and D. D. Dionysiou, “A review on the visible light active titanium dioxide photocatalysts for environmental applications” Appl. Catal. B, 125, pp. 331-349, 2012.
[4]A. Kay, I. Cesar and M. Gr¨atzel, “New Benchmark for Water Photooxidation by Nanostructured α-Fe2O3 Films,” J. Am. Chem. Soc., 128, pp. 15714-15721, 2006.
[5]X. H. Zhang, X. H. Lu, Y. Q. Shen, J. B. Han, L. Y. Yuan, L. Gong, Z. Xu, X. D. Bai, M. Wei, Y. X. Tong, Y. H. Gao, J. Chen, J. Zhou and Z. L. Wang, “three-dimensional WO3 nanostructures on carbon paper: photoelectrochemical property and visible light driven photocatalysis,” Chem. Commun., 47, pp.5804-5806, 2011.
[6]R. T. Ross and A. J. Nozik, “Efficiency of hot‐carrier solar energy converters,” J. Appl. Phys., 53, pp. 3813-3818, 1982.
[7]R. D. Schaller and V. I. Klimov, “High Efficiency Carrier Multiplication in PbSe Nanocrystals: Implications for Solar Energy Conversion” Phys. Rev. Lett., 92, pp. 186601, 2004.
[8]A. Kleiman-Shwarsctein, Y.-S. Hu, A. J. Forman, G. D. Stucky and E. W. McFarland, “Electrodeposition of α-Fe2O3 Doped with Mo or Cr as Photoanodes for Photocatalytic Water Splitting,” J. Phys. Chem. C, 112, pp.15900-15907, 2008.
[9]A. Kleiman-Shwarsctein, M. N. Huda, A. Walsh, Y. F. Yan, G. D. Stucky, Y. S. Hu, M. M. Al-Jassim and E. W. McFarland, “Electrodeposited Aluminum-Doped α-Fe2O3 Photoelectrodes: Experiment and Theory,” Chem. Mater., 22, pp. 510-517, 2010.
[10]Jiayong Gan, Xihong Lu and Yexiang Tong, “Towards highly efficient photoanodes: boosting sunlight-driven semiconductor nanomaterials for water oxidation,” Nanoscale, 6, pp. 7142-7164, 2014.
[11]M. G. Kibria and Z. Mi, “Artificial photosynthesis using metal/nonmetal-nitride semiconductors: current status, prospects, and challenges,” J. Mater. Chem. A, 4, pp. 2801-2820, 2016.
[12]J. Wu, “When group-III nitrides go infrared: New properties and perspectives” J. Appl. Phys., 106, 011101, 2009.
[13]A. G. Bhuiyan, A. Hashimoto and A. Yamamoto, “Indium nitride (InN): A review on growth, characterization, and properties,” J. Appl. Phys., 94, pp. 2779–2808, 2003.
[14]O. Ambacher, “Growth and applications of group III-nitrides,” J. Phys. D: Appl. Phys., 31, pp. 2653-2710, 1998.
[15]B. E. A. Saleh and M. C. Teich, “Fundamental of Photonics,” John Wiley and Sons, Hoboken, New Jersey, 2007.
[16]Scott C. Warren and Elijah Thimsen, “Plasmonic solar water splitting,” Energy Environ. Sci., 5, 5133, 2012.
[17]Jeremy D. Ruth, Larry M. Hayes, Daniel Ramirez Martin and Kenan Hatipoglu, “An Overview of Photoelectrochemical Cells (PEC) Mimicking Nature to Produce Hydrogen for Fuel Cells,” IEEE, 2017.
[18]Snigdha Rai , Ashi Ikram , Sonal Sahai , Sahab Dass , Rohit Shrivastav , Vibha R. Satsangi, “CNT based photoelectrodes for PEC generation of hydrogen: A review,” International Journal of Hydrogen Energy, 42, pp. 3994-4006, 2017.
[19]Mengpei Jiang, Hongjun Wu, Zhida Li, Deqiang Ji, Wei Li, Yue Liu, Dandan Yuan, Baohui Wang, and Zhonghai Zhang, “Highly Selective Photoelectrochemical Conversion of Carbon Dioxide to Formic Acid,” ACS Sustainable Chem. Eng., 6, pp. 82−87, 2018.
[20]Yahui Yang, Faqi Zhan, Hang Li, Wenhua Liu and Sha Yu, “In situ Sn-doped WO3 films with enhanced photoelectrochemical performance for reducing CO2 into formic acid,” J Solid State Electrochem, 21, pp. 2231–2240, 2017.
[21]Yahui Yang, Faqi Zhan, Hang Li, Wenhua Liu and Sha Yu, “Temperature effect on water splitting using a Si-doped hematite,” Journal of Power Sources, 272, pp. 567-580, 2014.
[22]Hen Dotan, Nripan Mathews, Takashi Hisatomi, Michael Grätzel and Avner Rothschild, “On the Solar to Hydrogen Conversion Efficiency of Photoelectrodes for Water Splitting,” J. Phys. Chem. Lett., 5 (19), pp. 3330–3334, 2014.
[23]T. Ogita, Y. Uetake, Y. Yamashita, A. Kuramata, S. Yamakoshi, and K. Ohkawa, “InGaN photocatalysts on conductive Ga2O3 substrates,” Phys. Status Solidi A, vol. 212, pp. 1029-1032, 2015.
[24]李言榮、惲正中，材料物理學概論，五南出版，第60-61頁，2003。
[25]Katherine A.Willets and Richard P. Van Duyne, “Localized Surface Plasmon Resonance Spectroscopy and Sensing,” Annu. Rev. Phys. Chem., 58, pp. 267–297, 2007.
[26]Kathryn M. Mayer and Jason H. Hafner, “Localized Surface Plasmon Resonance Sensors,” Chem. Rev., 111, pp. 3828–3857, 2011.
[27]Ya-Ju Lee, Chia-Ching Lin, Hsiao-Chin Lee, Yung-Chi Yao, Monima Sarma, Hai-Ching Su, Zu-Po Yang and Ken-Tsung Wong, “A demonstration of solid-state white light-emitting electrochemical cells using the integrated on-chip plasmonic notch filters,” J. Mater. Chem. C, 4, pp. 1599-1605, 2016.
[28]李彥徵，成功大學光電工程學系，“侷域性表面電漿應用於光電化學分解水產氫特性之研究”，2017年
[29]鄭新諺，成功大學光電工程學系，“離子佈植技術應用於氮化鎵系列光電元件”，2017年
[30]Shekhar Agnihotri, Soumyo Mukherji and Suparna Mukherji, “Sized-controlled silver nanoparticals synthesized over the range 5-100 nm using the same protocol and their antibacterial efficacy”, RSC Adv., 4, pp. 3974 – 3983, 2014.
[31]Xiaotong Liu, Dabing Li, Xiaojuan Sun, Zhiming Li, Hang Song, Hong Jiang and Yiren Chen, “Tunable Dipole Surface Plasmon Resonances of Silver Nanoparticles by Cladding Dielectric Layers”, Scientific Reports, 2015.