本實驗是利用三五族氮化鎵半導體，應用於光電化學水分解系統中當作工作電極，因為氮化鎵具有寬能隙足夠跨越氧化還原電位。但經過長時間的光電化學量測後會使氮化鎵表面產生嚴重的腐蝕現象，所以本次論文將會探討有效利用氧化物的催化作用，使載子能夠更容易傳輸至電解液，改善氮化鎵與電解液直接接觸造成腐蝕現象。
所以本次實驗使用鎳與鈷粉末作為前驅物配置氧化鎳與氧化鈷溶液旋塗於氮化鎵基板上，於光電化學量測中作為工作電極，量測長時間光電流及分析材料特性。
最後，由實驗結果得到，氧化鎳在本次實驗具有催化作用，可以增加載子傳輸，且由表面分析可觀察出，氮化鎵有覆蓋一層氧化鎳後確實有達到抗腐蝕效果，且光電流有提升。但氧化鈷實驗中，催化效果較不顯著，推測因為氧化物材料本身旋塗的厚度，所以影響載子傳輸，使光電流偏低。

In this experiment, we used nickel oxide (NiOX) and cobalt oxide (CoOX) to cover n-type gallium nitride (n-GaN) to reduce surface corrosion of gallium nitride (GaN) semiconductors and electrolytes during long-term measurements. Nickel (Ni) and cobalt (Co) powders were used as precursors in the experiments. The precursor is synthesized synthetically. Finally, the spin coating method was uniformly applied to the surface of gallium nitride (GaN), and the surface oxide characteristics were analyzed by using different annealing temperatures. It is observed by the photoelectrochemical system that nickel oxide (NiOX) has a catalytic action, so that holes can be introduced into the electrolyte more quickly, and gallium nitride covering nickel oxide (NiOX) is used for a long period of time with less corrosion. The photocurrent of cobalt oxide (CoOX) is lower than that of gallium nitride (GaN). It is speculated that the thickness of the cobalt oxide film is too thick, thereby hindering carrier transport and low photocurrent.

[1] T. Bradford, Solar revolution: the economic transformation of the global energy industry. MIT Press, 2008.
[2] F. Walsh, "FARADAY AND HIS LAWS OF ELECTROLYSIS: AN APPRECIATION," Bulletin of Electrochemistry, vol. 7, no. 11, pp. 481-484, 1992.
[3] J. Xu and G. F. Froment, "Methane steam reforming, methanation and water‐gas shift: I. Intrinsic kinetics," AIChE journal, vol. 35, no. 1, pp. 88-96, 1989.
[4] S. Abanades and G. Flamant, "Thermochemical hydrogen production from a two-step solar-driven water-splitting cycle based on cerium oxides," Solar energy, vol. 80, no. 12, pp. 1611-1623, 2006.
[5] A. V. Bridgwater, "Review of fast pyrolysis of biomass and product upgrading," Biomass and bioenergy, vol. 38, pp. 68-94, 2012.
[6] A. Fujishima and K. Honda, "Electrochemical photolysis of water at a semiconductor electrode," nature, vol. 238, no. 5358, p. 37, 1972.
[7] A. Fujishima, K. Kohayakawa, and K. Honda, "Hydrogen production under sunlight with an electrochemical photocell," Journal of the Electrochemical Society, vol. 122, pp. 1487-1489, 1975.
[8] M. Halmann, "Photoelectrochemical reduction of aqueous carbon dioxide on p-type gallium phosphide in liquid junction solar cells," Nature, vol. 275, no. 5676, p. 115, 1978.
[9] K. Fujii, T. Karasawa, and K. Ohkawa, "Hydrogen gas generation by splitting aqueous water using n-type GaN photoelectrode with anodic oxidation," Japanese journal of applied physics, vol. 44, no. 4L, p. L543, 2005.
[10] F. A. Chowdhury, Z. Mi, M. G. Kibria, and M. L. Trudeau, "Group III-nitride nanowire structures for photocatalytic hydrogen evolution under visible light irradiation," APL Materials, vol. 3, no. 10, p. 104408, 2015.
[11] S. Yotsuhashi et al., "Photo-induced CO2 reduction with GaN electrode in aqueous system," Applied Physics Express, vol. 4, no. 11, p. 117101, 2011.
[12] S.-W. Ryu, Y. Zhang, B. Leung, C. Yerino, and J. Han, "Improved photoelectrochemical water splitting efficiency of nanoporous GaN photoanode," Semiconductor Science and Technology, vol. 27, no. 1, p. 015014, 2011.
[13] A. Huerta-Flores, L. M. Torres-Martínez, E. Moctezuma, and O. Ceballos-Sanchez, "Enhanced photocatalytic activity for hydrogen evolution of SrZrO3 modified with earth abundant metal oxides (MO, M= Cu, Ni, Fe, Co)," Fuel, vol. 181, pp. 670-679, 2016.
[14] S. A. Lee et al., "Tailored NiO x/Ni Cocatalysts on Silicon for Highly Efficient Water Splitting Photoanodes via Pulsed Electrodeposition," ACS Catalysis, vol. 8, no. 8, pp. 7261-7269, 2018.
[15] L.-F. Huang, M. Hutchison, R. Santucci Jr, J. R. Scully, and J. M. Rondinelli, "Improved electrochemical phase diagrams from theory and experiment: the Ni–water system and its complex compounds," The Journal of Physical Chemistry C, vol. 121, no. 18, pp. 9782-9789, 2017.
[16] S. Klaus, Y. Cai, M. W. Louie, L. Trotochaud, and A. T. Bell, "Effects of Fe electrolyte impurities on Ni (OH) 2/NiOOH structure and oxygen evolution activity," The Journal of Physical Chemistry C, vol. 119, no. 13, pp. 7243-7254, 2015.
[17] K. Wu, D. Shen, Q. Meng, and J. Wang, "Octahedral Co3O4 particles with high electrochemical surface area as electrocatalyst for water splitting," Electrochimica Acta, vol. 288, pp. 82-90, 2018.
[18] Z. Chen et al., "Accelerating materials development for photoelectrochemical hydrogen production: Standards for methods, definitions, and reporting protocols," Journal of Materials Research, vol. 25, no. 1, pp. 3-16, 2010.
[19] Z. Chen, H. N. Dinh, and E. Miller, Photoelectrochemical water splitting. Springer, 2013.
[20] R. Asahi, T. Morikawa, T. Ohwaki, K. Aoki, and Y. Taga, "Photocatalysts sensitive to visible light-response," Science, vol. 295, no. 5555, pp. 627-627, 2002.
[21] H. P. Maruska and A. K. Ghosh, "Transition-metal dopants for extending the response of titanate photoelectrolysis anodes," Solar Energy Materials, vol. 1, no. 3-4, pp. 237-247, 1979.
[22] H. Kato and A. Kudo, "Visible-light-response and photocatalytic activities of TiO2 and SrTiO3 photocatalysts codoped with antimony and chromium," The Journal of Physical Chemistry B, vol. 106, no. 19, pp. 5029-5034, 2002.
[23] S. Sze, "Physics of semiconductor devicesWiley Eastern," New York, 1981.
[24] P. D. Tran, L. H. Wong, J. Barber, and J. S. Loo, "Recent advances in hybrid photocatalysts for solar fuel production," Energy & Environmental Science, vol. 5, no. 3, pp. 5902-5918, 2012.
[25] J.-Y. Jung, J.-Y. Yu, and J.-H. Lee, "Dynamic Photoelectrochemical Device with Open-Circuit Potential Insensitive to Thermodynamic Voltage Loss," The journal of physical chemistry letters, vol. 9, no. 18, pp. 5412-5418, 2018.
[26] T. Ogita, Y. Uetake, Y. Yamashita, A. Kuramata, S. Yamakoshi, and K. Ohkawa, "InGaN photocatalysts on conductive Ga2O3 substrates," physica status solidi (a), vol. 212, no. 5, pp. 1029-1032, 2015.
[27] T. Sekimoto et al., "Tandem photo-electrode of InGaN with two Si pn junctions for CO2 conversion to HCOOH with the efficiency greater than biological photosynthesis," Applied Physics Letters, vol. 106, no. 7, p. 073902, 2015.
[28] C. V. Raman and K. S. Krishnan, "A new type of secondary radiation," Nature, vol. 121, no. 3048, p. 501, 1928.
[29] M. Baker, K. A. Hollywood, and C. Hughes, Biophotonics: Vibrational Spectroscopic Diagnostics. Morgan & Claypool Publishers, 2016.
[30] M. P. Seah and W. Dench, "Quantitative electron spectroscopy of surfaces: A standard data base for electron inelastic mean free paths in solids," Surface and interface analysis, vol. 1, no. 1, pp. 2-11, 1979.
[31] 張立信, "surface chemical anailsis techniques," pp. 17-23.
[32] E. L. Abbe, Henry (ed.). Translated by Fripp, H. E, " A Contribution to the Theory of the Microscope and the Nature of Microscopic Vision," Proceedings of the Bristol Naturalists' Society, pp. 200-261.
[33] B. Inkson, "Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) for materials characterization," in Materials characterization using nondestructive evaluation (NDE) methods: Elsevier, 2016, pp. 17-43.
[34] G. Binnig, C. F. Quate, and C. Gerber, "Atomic force microscope," Physical review letters, vol. 56, no. 9, p. 930, 1986.
[35] I. S. Bozchalooi, A. C. Houck, J. AlGhamdi, and K. Youcef-Toumi, "Design and control of multi-actuated atomic force microscope for large-range and high-speed imaging," Ultramicroscopy, vol. 160, pp. 213-224, 2016.
[36] A. Kudo and Y. Miseki, "Heterogeneous photocatalyst materials for water splitting," Chemical Society Reviews, vol. 38, no. 1, pp. 253-278, 2009.
[37] Y. K. Chih et al., "NiOx Electrode Interlayer and CH3NH2/CH3NH3PbBr3 Interface Treatment to Markedly Advance Hybrid Perovskite‐Based Light‐Emitting Diodes," Advanced Materials, vol. 28, no. 39, pp. 8687-8694, 2016.
[38] F. Thema, E. Manikandan, A. Gurib-Fakim, and M. Maaza, "Single phase Bunsenite NiO nanoparticles green synthesis by Agathosma betulina natural extract," Journal of alloys and compounds, vol. 657, pp. 655-661, 2016.
[39] N. Weidler et al., "X-ray Photoelectron Spectroscopic Investigation of Plasma-Enhanced Chemical Vapor Deposited NiO x, NiO x (OH) y, and CoNiO x (OH) y: Influence of the Chemical Composition on the Catalytic Activity for the Oxygen Evolution Reaction," The Journal of Physical Chemistry C, vol. 121, no. 12, pp. 6455-6463, 2017.
[40] J.-W. Lang, L.-B. Kong, W.-J. Wu, Y.-C. Luo, and L. Kang, "Facile approach to prepare loose-packed NiO nano-flakes materials for supercapacitors," Chemical Communications, no. 35, pp. 4213-4215, 2008.