本實驗以分子束磊晶法於純銅基板上成長氧化亞銅磊晶，探討成長溫度、氧氣壓力以及氧氣電漿功率，對於氧化亞銅磊晶成長與表面形貌的影響。第一階段實驗使用多晶銅基板，透過X光繞射、電子背向散射繞射儀、穿透式電子顯微鏡、掃描式電子顯微鏡和X光光電子能譜，分析所成長薄膜的晶體結構、結晶方位、表面形貌和成分組成。實驗結果發現，在300 – 650 oC之間成長的薄膜均成功成長氧化亞銅，且無氧化銅存在。在低溫（300 oC）下磊晶成長被抑制，導致在不同方位的基板晶粒上，均成長為多晶薄膜。當基板溫度逐漸上升至600 oC以上時，方位為<110>//ND與<111>//ND的基板晶粒上，氧化亞銅可以磊晶方式成長。除了溫度之外，磊晶成長現象僅存在於特定的氧氣壓力與氧氣電漿功率區間，在高氧氣電漿功率（300 W）之下，磊晶成長出現在低氧分壓（5 x 10-6 mbar）之下。氧氣電漿功率降至100 – 200 W時，磊晶成長出現在氧分壓為1 x 10-5 mbar之下。此外，基板晶粒的方位也會影響磊晶成長，在<110>//ND與<111>//ND的基板晶粒上容許磊晶以cube-on-cube的方位關係成長，而<100>//ND的磊晶則未發現。以前述條件在(111)單晶銅基板上成長(111)氧化亞銅磊晶，但是出現雙晶（<111>/60o）的變量，意即有兩組互為雙晶關係的磊晶同時成長於基板表面。電子背向散射繞射分析顯示這兩組雙晶變量呈現條狀交錯分布於基板表面，顯示磊晶係以島狀模式成長。由反射光譜計算得知(111)的氧化亞銅磊晶的能隙值為2.02 eV，室溫光致螢光光譜的結果顯示磊晶於1.6 - 1.8 eV處產生非常強的近能隙發光峰，且沒有多餘深層能階的發光峰存在。

Attempts of growing cuprous oxide (Cu2O) epitaxial film on Cu substrate by molecular beam epitaxy were made in this work. The main purpose is to clarify the effect of processing parameters, including substrate temperature, oxygen pressure and oxygen plasma power, on epitaxial growth. In the first stage of experiment, polycrystalline Cu substrates were used. The grown films were analyzed by x-ray diffraction, transmission electron microscope, scanning electron microscope, electron backscatter diffraction and x-ray photoelectron spectroscopy. Results showed that Cu2O could grow epitaxially on Cu grains with orientations of <110>//ND and <111>//ND when the films were deposited at substrate temperature of 600 oC or high. However, all the Cu2O deposited on each Cu grain were polycrystalline no matter its orientation when the films were deposited at a temperature below 600 oC. Further experiments indicated that the Cu2O epilayers were grown successfully on most of the <110>//ND and <111>//ND grains at PO2 = 1x10-5 mbar with the plasma power 100-200W. No photoelectron peaks contributed from Cu0 and Cu2+ were identified by X-ray photoelectron spectroscopy for films deposited in the above-mentioned condition. Transmission electron microscopy analysis showed that the films deposited epitaxially remain a cube-on-cube orientation relationship with the underlying Cu grains of <110>//ND and <111>//ND. In the second stage of experiment, Cu2O were grown on Cu single crystal substrates. Cu2O was grown epitaxially on (111) substrate and the (111) rocking curve exhibited a full width at half maximum of 1.7o. X-ray phi scan showed that a <111>/60o twin variant existed. The epilayer have a bandgap of 2.01eV and showed a strong emission at 2 eV and moderate emission at 1.6-1.8 eV analyzed by photoluminescence spectroscopy at 300K. Only very weak deep-level emission was found in the photoluminescence spectrum.

論文審定書 i
致謝 ii
摘要 iv
Abstract v
目錄 vii
表次 x
圖次 x
第一章 前言 1
第二章 理論基礎與文獻回顧 3
2. 1 分子束磊晶法 3
2. 2 分子束磊晶系統 3
2. 2. 1 分子束蒸鍍源 3
2. 2. 2 泵浦 4
2. 2. 3 真空計 4
2. 2. 4 反射式高能量電子繞射儀(Reflection high-energy electron diffraction, RHEED) 5
2. 3 磊晶成長 5
2. 3. 1 成核機制 6
2. 3. 2 成長模式 6
2. 3. 3 晶格失配率 7
2. 4 基板選擇 8
2. 5 氧化亞銅的基本特性與應用 8
2. 5. 1 結構與特性 8
2. 5. 2 應用 9
2. 6氧化亞銅的製備方法 10
2. 6. 1 多晶氧化亞銅製備 11
2. 6. 2 磊晶氧化亞銅研究 17
2. 7 Cu2O的分析方法 21
2. 7. 1 X光光電子能譜(X-ray photoelectron spectroscopy, XPS) 21
2. 7. 2 光致螢光光譜(Photoluminescence, PL) 21
第三章 實驗方法與步驟 23
3. 1 基板準備與前處理 23
3. 2 磊晶成長步驟 24
3. 3 實驗分析方法 24
3. 3. 1 X光繞射(X-ray diffraction, XRD)分析 24
3. 3. 2 X光光電子能譜分析 24
3. 3. 3 掃描式電子顯微鏡(Scanning Electron Microscope, SEM)分析 25
3. 3. 4 背向散射電子繞射(Electron Backscatter Diffraction, EBSD)分析 25
3. 3. 5 穿透式電子顯微鏡(Transmission electron microscope, TEM)分析 25
3. 3. 6 反射光譜(Reflectance spectrum )分析 26
3. 3. 7 光致螢光光譜分析 26
第四章 實驗結果 27
4. 1 多晶銅基板表面形貌與晶粒方位分析 27
4. 2 基板溫度對氧化亞銅磊晶成長的影響 27
4. 3 氧氣電漿功率與壓力對氧化亞銅磊晶成長的影響 31
4. 3. 1 高氧氣電漿功率(300W)之下的磊晶成長 31
4. 3. 2 中氧氣電漿功率(200W)之下的磊晶成長 32
4. 3. 3 低氧氣電漿功率(100W)之下的磊晶成長 34
4. 3. 4 最佳氧氣壓力與氧電漿下，溫度對磊晶成長的影響 36
4. 4 最佳氧化亞銅成長參數晶體結構分析 38
4. 4. 1 最佳參數P2-2試片TEM分析 38
4. 4. 2 最佳成長條件於單晶銅<111>基板上成長氧化亞銅 39
4. 4. 2 最佳成長條件於單晶銅<100>基板上成長氧化亞銅 40
4. 5 特性分析 40
4. 5. 1 反射光譜分析 40
4. 5. 2 PL光譜分析 41
第五章 討論 42
5. 1 高晶格失配率下的磊晶成長 42
5. 2 基板溫度對氧化亞銅磊晶成長的影響 42
5. 3 氧氣壓力與電漿功率對氧化亞銅成長的影響 43
5. 4 基板晶粒方位對磊晶成長的影響 45
5. 5 最佳條件下的磊晶品質 46
5. 6 純銅基板以熱氧化法與MgO基板以MBE成長氧化亞銅的文獻比較 47
結論 49
參考文獻 50
表格 57
圖片 65

[1] V. Smil, "Energy: a beginner's guide." Oneworld Publications, (2006).
[2] B. K. Meyer, A. Polity, D. Reppin, M. Becker, P. Hering, P. J. Klar, Th. Sander, C. Reindl, J. Benz, M. Eickhoff, C. Heiliger, M. Heinemann, J. Bläsing, A. Krost, S. Shokovets, C. Müller, & C. Ronning, “Binary copper oxide semiconductors: from materials towards devices”, Physica Status Solidi (b) 249.8 (2012) 1487-1509.
[3] W. Shockley, & H. J. Queisser. “Detailed balance limit of efficiency of p‐n junction solar cells”, Journal of Applied Physics 32.3 (1961) 510-519.
[4] A. Mittiga, E. Salza, F. Sarto, M. Tucci, & R. Vasanthi, “Heterojunction solar cell with 2% efficiency based on a Cu2O substrate”, Applied Physics Letters 88.16 (2006) 163502-163502.
[5] B. Tazenkov, & F. Gruzdev, “Effect of electric-field on hole mobility in cuprous-oxide”, Solid State Physics 18.12 (1976) 3716-3718.
[6] A. Y. Cho, & J. R. Arthur. “Molecular beam epitaxy”, Progress in solid state chemistry 10 (1975) 157-191.
[7] J. R. Arthur. “Molecular beam epitaxy”, Surface science 500.1 (2002) 189-217.
[8] Y. Su, T. Sawada, J. Takemotob, & S. Haga “Theoretical study on the pumping mechanism of a dry scroll vacuum pump”, Vacuum 47.6 (1996) 815-818.
[9] S.S. Jeong, A. Mittiga, E. Salza, A. Masci, & S. Passerini ,”Electrodeposited ZnO/Cu2O heterojunction solar cells”, Electrochimica Acta 53.5 (2008) 2226-2231.
[10] B. A. Joyce. P. J. Dobson, J. H. Neave, & K. Woodbridge, “RHEED studies of heterojunction and quantum well formation during MBE growth—from multiple scattering to band offsets”, Surface Science 168 (1986) 423-438.
[11] G. Kaur, A. Mitra, & K. L. Yadav. “Influence of oxygen pressure on the growth and physical properties of pulsed laser deposited Cu2O thin films”, Journal of Materials Science: Materials in Electronics 26.12 (2015) 9689-9699.
[12] J. E. Ayers, & T. Kujofsa, “Heteroepitaxy of semiconductors: theory: growth, and characterization”, CRC press, (2007).
[13] 1 H. J. Li, C. Y. Pu, C. Y. Ma, S. Li, W.J. Dong, S. Y. Bao, & Q. Y. Zhang, “Growth behavior and optical properties of N-doped Cu2O films”, Thin Solid Films 520.1 (2011) 212-216.
[14] K. N. Tu, J. W. Mayer, & L. C. Feldman, “Electronic thin film science”, Macmillan press, (1992).
[15] D. J. Miller, J. D. Hettinger , R. P. Chiarello, & H. K. Kim, “Epitaxial growth of Cu2O films on MgO by sputtering”, Journal of materials research 7.10 (1992).
[16] M. Zouaghi, M. Tapiero, J.P. Zielinger, & R. Burgraf, “Hall mobility and hole density in photoactivated Cu2O single crystals”, Solid State Communications 8.22 (1970) 1823-1825.
[17] S. H. Wee, P. S. Huang, J. K. Lee, & A. Goyal “Heteroepitaxial Cu2O thin film solar cell on metallic substrates”, Scientific reports 5 (2015).
[18] H. Shimada, & T. Masumi. “Hall mobility of positive holes in Cu2O”, Journal of the Physical Society of Japan 58.5 (1989) 1717-1724.
[19] F. Biccari. “Defects and doping in Cu2O”, PhD thesis in Sapienza University, 2012.
[20] L. C. Olsen, F. W. Addis, & W. Miller. “Experimental and theoretical studies of Cu2O solar cells”, Solar cells 7.3 (1982) 247-279.
[21] J. N. Kondo, “Cu2O as a photocatalyst for overall water splitting under visible light irradiation”, Chemical Communications 3 (1998) 357-358.
[22] J. L. Lin, & J. P. Wolfe, “Bose-Einstein condensation of paraexcitons in stressed Cu2O”, Physical Review Letters 71.8 (1993) 1222.
[23] K. Nomura, H. Ohta, A. Takagi, T. Kamiya, M. Hirano, & H. Hosono, “Room-temperature fabrication of transparent flexible thin-film transistors using amorphous oxide semiconductors”, Nature 432.7016 (2004) 488-492.
[24] H. C. Lu, C. L. Chu, C. Y. Lai, & Y. H. Wang, “Property variations of direct-current reactive magnetron sputtered copper oxide thin films deposited at different oxygen partial pressures”, Thin Solid Films 517.15 (2009) 4408-4412
[25] J. J. Loferski “Theoretical considerations governing the choice of the optimum semiconductor for photovoltaic solar energy conversion”, Journal of Applied Physics 27.7 (1956) 777-784.
[26] L. O. Grondahl, “A new type of contact rectifier”, Physical Review Letters 27 (1926) 803.
[27] L. C. Chen, “Review of preparation and optoelectronic characteristics of Cu2O-based solar cells with nanostructure”, Materials Science in Semiconductor Processing 16.5 (2013) 1172-1185.
[28] A. O. Musa, T. Akomolafe, & M. J. Carter. “Production of cuprous oxide, a solar cell material, by thermal oxidation and a study of its physical and electrical properties”, Solar Energy Materials and Solar Cells 51.3 (1998) 305-316.
[29] T. Minami, Y. Nishi, & T. Miyata, “Heterojunction solar cell with 6% efficiency based on an n-type aluminum–gallium–oxide thin film and p-type sodium-doped Cu2O sheet”, Applied Physics Express 8.2 (2015) 022301.
[30] C.C. Chen, L. C. Chen, & Y. H. Lee. “Fabrication and Optoelectrical Properties of IZO/Heterostructure Solar Cells by Thermal Oxidation”, Advances in Condensed Matter Physics 2012 (2012).
[31] M. Izaki, T. Shinagawa, K. T. Mizuno, Y. Ida, M. Inaba, & A. Tasaka, “Electrochemically constructed p-Cu2O/n-ZnO heterojunction diode for photovoltaic device”, Journal of Physics D: Applied Physics 40.11 (2007) 3326.
[32] J. Cui, & U. J. Gibson. “A simple two-step electrodeposition of Cu2O/ZnO nanopillar solar cells”, The Journal of Physical Chemistry C 114.14 (2010) 6408-6412.
[33] S. Ishizuka, T. Maruyama, & K. Akimoto. “Thin-film deposition of Cu2O by reactive radio-frequency magnetron sputtering”, Japanese Journal of Applied Physics 39.8A (2000) 786.
[34] W. Y. Yang, W. G. Kim, & S. W. Rhee. “Radio frequency sputter deposition of single phase cuprous oxide using Cu2O as a target material and its resistive switching properties”, Thin Solid Films 517.2 (2008) 967-971.
[35] K. Akimoto, S. Ishizuka, M. Yanagita, Y. Nawa, Goutam K. Paul, & T. Sakurai, “Thin film deposition of Cu2O and application for solar cells”, Solar energy 80.6 (2006) 715-722.
[36] B. S. Li, K. Akimoto, & A. Shen, “Growth of Cu2O thin films with high hole mobility by introducing a low-temperature buffer layer”, Journal of Crystal Growth 311.4 (2009) 1102-1105.
[37] N. Kikuchi, & K. Tonooka, “Electrical and structural properties of Ni-doped Cu2O films prepared by pulsed laser deposition”, Thin Solid Films 486.1 (2005) 33-37.
[38] L. D. L. S. Valladares, D. H. Salinas, A. B. Dominguez, D. A. Najarro, S.I. Khondaker, T. Mitrelias, C.H.W. Barnes, J. A. Aguiar, & Y. Majima, “Crystallization and electrical resistivity of Cu2O and CuO obtained by thermal oxidation of Cu thin films on SiO2/Si substrates”, Thin Solid Films 520.20 (2012) 6368-6374.
[39] Y. Nishi, T. Miyata, & T. Minami. “Electrochemically deposited Cu2O thin films on thermally oxidized Cu2O sheets for solar cell applications”, Solar Energy Materials and Solar Cells 155 (2016) 405-410.
[40] J. Gan, S. Gorantla, H. N. Riise, Ø. S. Fjellvåg, S. Diplas, O. M. Løvvik, B. G. Svensson, E. V. Monakhov, & A. E. Gunnæs, “Structural properties of Cu2O epitaxial films grown on c-axis single crystal ZnO by magnetron sputtering”, Applied Physics Letters 108.15 (2016) 152110.
[41] S. H. Wee, P. S. Huang, J. K. Lee, & A. Goyal, “Heteroepitaxial Cu2O thin film solar cell on metallic substrates”, Scientific reports 5 (2015).
[42] K. Matsuzaki, K. Nomura, H. Yanagi, T. Kamiya, M. Hirano, H. Hosono, “Epitaxial growth of high mobility Cu2O thin films and application to p-channel thin film transistor”, Applied Physics Letters 93.20 (2008) 2107.
[43] D. S. Darvish, & H. A. Atwater. “Epitaxial growth of Cu2O and ZnO/Cu2O thin films on MgO by plasma-assisted molecular beam epitaxy”, Journal of Crystal Growth 319.1 (2011) 39-43.
[44] M. Kracht, J. Schörmann, & M. Eickhoff. “Plasma assisted molecular beam epitaxy of Cu2O on MgO (001) Influence of copper flux on epitaxial orientation”, Journal of Crystal Growth 436 (2016) 87-91.
[45] Y. Tolstova, S. S. Wilson, S. T. Omelchenko, N. S. Lewis, & H.A. Atwater, “Molecular Beam Epitaxy of Cu2O Heterostructures for Photovoltaics”, Photovoltaic Specialist Conference, 2015 IEEE 42nd., 2015.
[46] W. Huo, J. Shi, Z. Mei, L. Liu, J. Li, L. Gu, X. Du, & Q. Xue, “High-index Cu2O (113) film on faceted MgO (110) by molecular beam epitaxy”, Journal of Crystal Growth 420 (2015) 32-36.
[47] Y. Tolstova, S. S. Wilson, & H. A. Atwater, “Single phase, single orientation Cu2O (100) and (110) thin films grown by plasma-assisted molecular beam epitaxy”, Journal of Crystal Growth 410 (2015) 77-81.
[48] J. P. Tobin, W. Hirschwald, & J. Cunningham, “XPS and XAES studies of transient enhancement of Cu1 at CuO surfaces during vacuum outgassing”, Applications of Surface Science 16.3 (1983) 441-452.
[49] 周葦葶，國立中山大學材料與光電科學學系專題研究計畫，(2014)。
[50] H. Solache-Carranco, G. Jua ́rez-Dı ́az, A. Esparza-Garcı ́a, M. Brisen ̃o-Garcı ́a, M. Galva ́n-Arellano, J. Martı ́nez-Jua ́rez, G. Romero-Paredes, R. Pen ̃a-Sierra, "Photoluminescence & X-ray diffraction studies on Cu 2 O." Journal of Luminescence 129.12 (2009) 1483-1487.
[51] V. Randle & O. Engler, “Introduction to texture analysis: macrotexture, microtexture, and orientation mapping.” CRC press, (2009).
[52] H. Matsumura, A. Fujii, & T. Kitatani, “Properties of high-mobility Cu2O films prepared by thermal oxidation of Cu at low temperatures”, Japanese journal of applied physics 35.11 (1996) 5631.
[53] T. Minami, Y. Nishi, T. Miyata, & J. Nomoto, “High-efficiency oxide solar cells with ZnO/Cu2O heterojunction fabricated on thermally oxidized Cu2O sheets”, Applied physics express 4.6 (2011) 062301.
[54] T. Minami, Y. Nishi, & T. Miyata, “High-efficiency Cu2O-based heterojunction solar cells fabricated using a Ga2O3 thin film as n-type layer”, Applied Physics Express 6.4 (2013) 044101.
[55] J. Katayama, K. Ito, M. Matsuoka, & J. Tamaki, “Performance of Cu2O/ZnO solar cell prepared by two-step electrodeposition”, Journal of Applied Electrochemistry 34.7 (2004) 687-692
[56] K. Han, & M. Tao, “Electrochemically deposited p–n homojunction cuprous oxide solar cells”, Solar Energy Materials and Solar Cells 93.1 (2009) 153-157.
[57] T. Ito, & T. Masumi. “Detailed Examination of Relaxation Processes of Excitons in Photoluminescence Spectra of Cu2O”, Journal of the Physical Society of Japan 66.7 (1997) 2185-2193.
[58] 呂政穎，分子束磊晶法成長氧化鋅之研究，國立中山大學材料與光電科學學系碩士論文，(2009)。
[59] 侯映君，電鍍參數對鎳在多晶銅基板上電鍍磊晶成長的研究，國立中山大學材料與光電科學學系碩士論文，(2014)。
[60] D. A. Porter, K. E. Easterling, and M. Sherif. Phase Transformations in Metals and Alloys, Revised Reprint, CRC press, (2009).
[61] A. Trampert., and K. H. Ploog. "Heteroepitaxy of Large‐Misfit Systems: Role of Coincidence Lattice." Crystal Research and Technology 35.6 (2000) 793-806.
[62] 溫孟潔，在氧化鎂基板上成長氧化亞銅磊晶之研究，國立中山大學材料與光電科學學系博士論文計畫，(2015)。
[63] X. Lian, P. Xiao, S. C Yang, R. Liu & G. Henkelman, "Calculations of oxide formation on low-index Cu surfaces." The Journal of chemical physics 145.4 (2016) 044711.
[64] L. Luo, Y. Kang, J. C. Yang & G. Zhou, "Effect of oxygen gas pressure on orientations of Cu2O nuclei during the initial oxidation of Cu (100),(110) and (111)." Surface Science 606.23 (2012) 1790-1797.