本研究以反應式離子束濺鍍法於SiO2及玻璃基板上以三種氬氧氣體比例在基板溫度300C下沉積氧化銅及摻鋁氧化銅薄膜，探討氣體流量及摻鋁濃度(0~10 at.%)對所沉積薄膜之影響。研究結果顯示當氬/氧氣體比例為3:2時，不論摻雜的鋁多寡，都會得到單相且表面平整的CuO薄膜，且經由鋁的摻雜，得出的(111)相位峰值有所位移，顯示鋁已摻入CuO中。且藉由鋁的摻雜，CuO薄膜由間接能隙轉為直接能隙，而薄膜光學能隙隨鋁的濃度增加而加大，約從2.45 eV上升至2.89 eV。當氬/氧氣體比例為2:1時，形成混相的CuO及Cu2O薄膜或沒有Cu2O相位的CuO薄膜，藉由鋁的摻雜，可見光穿透率能提升至約60%，光學能隙值的變化並不明顯。當氬/氧氣體比例為6:1時，不論摻雜的鋁多寡，皆得到表面平整的Cu2O薄膜，鋁的摻雜使薄膜穿透率提升至約70%，而光學能隙值的變化並不明顯。三種氣體比例沉積出的薄膜，皆因鋁的摻雜而導致電阻率的下降，約從500 Ω·cm下降至200 Ω·cm。

Aluminum doped copper oxide thin films have been deposited by reactive ion beam sputter deposition at 300C with an Ar:O2 ratio at 3:2, 2:1 and 6:1. With Ar:O2 ratio at 3:2, regardless of Al concentration, single phase CuO thin films were obtained. The introduction of Al results in CuO (111) diffraction peak shifting to larger angles, indicating the incorporation of Al in CuO. The introduction of Al results in change from indirect bandgap to direct bandgap and the bandgap of CuO increases from 2.45 eV to 2.89 eV as Al concentration reaches 10 at.%. With Ar:O2 ratio at 2:1, the thin films are mixed CuO and Cu2O phases or polycrystalline CuO. The introduction of Al results in increase of transmittance to 60%, while the bandgap remains the same. With Ar:O2 ratio at 6:1, polycrystalline Cu2O thin films were obtained regardless of Al concentration. The introduction of Al results in increase of transmittance to 70%, while the bandgap remains approximately the same. Doping of Al results in drop of the resistance from 500 Ω·cm to 200 Ω·cm for both CuO and Cu2O.

[1] R. G. Gordon, “Criteria for choosing transparent conductors,” MRS Bullentin, Vol. 25, pp. 52-57, 2000.
[2] R. L. Hoffman, B. J. Norris, and J. F. Wager, “ZnO-based transparent thin-film transistors,” Appl. Phys. Lett., Vol. 82, pp. 733-735, 2003.
[3] S.C. Ray, “Preparation of copper oxide thin film by the sol–gel-like dip technique and study of their structural and optical properties,” Sol. Energy Mater. Sol. Cells, Vol. 68, pp. 307-312, 2001.
[4] H. Kawazoe, M. Yasukawa, H. Hyodo, M. Kurita, H. Yanagi,, and H. Hosono, “P-type electrical conduction in transparent thin films of CuAlO2,” Nature, Vol. 389, pp. 939-942, 1997.
[5] K. Badeker, “Concerning the electricity conductibility and the thermoelectric energy of several heavy metal bonds,” Ann. Phys., Vol. 22, p. 749, 1907.
[6] H. Kawazoe, H. Yanagi, K. Ueda, and H. Hosono, “Transparent p-type conducting oxide: Design and fabrication of p-n heterojunctions,” MRS Bulletin, Vol. 25, pp.28-36, 2000.
[7] T. J. Coutts, D. L. Young, an X. Li, “Characterization of transparent conducting oxides,” MRS Bulletin, Vol. 25, pp. 58-65, 2000.
[8] T. Minami, “New n-type transparent conducting oxides,” MRS Bulletin, Vol. 25, pp. 38-44, 2000.
[9] 潘漢昌, 蕭銘華, 蘇健穎, 蕭健男, “透明導電膜簡介,” 科儀新知, Vol. 26, pp. 46-55, 2004.
[10] A. N. Banerjee, S. Kundoo, and K. K. Chattopadhyay, “Synthesis and characterization of p-type transparent conducting CuAlO2 thin film by DC sputtering,” Thin Solid Films, Vol. 440, pp. 5-10, 2003
[11] V. Assunçãoa, E. Fortunatoa, A. Marquesa, H. Águasa, I. Ferreiraa, M.E.V. Costab, and R. Martinsa, “Influence of the deposition pressure on the properties of transparent and conductive ZnO:Ga thin-film produced by r.f. sputtering at room temperature,” Thin Solid Films, Vol. 427, pp. 401-405, 2003.

[12] Y. S. Jung, J. Y. Seo, D. W. Lee, and D. Y. Jeon, “Influence of DC magnetron sputtering parameters on the properties of amorphous indium zinc oxide thin film,” Thin Solid Films, Vol. 445, pp. 63-71, 2003.
[13] P. F. Carcia, R. S. McLean, M. H. Reilly, and G. Nunes Jr, “Transparent ZnO thin-film transistor fabricated by rf magnetron sputtering,” Appl. Phys. Lett., Vol. 82, pp. 1117-1119, 2003
[14] M. Varasi, C. Misiano, and L. Lasaponara, “Deposition of optical thin films by ion beam sputtering,” Thin Solid Films, Vol. 117, pp. 163-172, 1984.
[15] L. Davis, “Properties of transparent conducting oxides deposited at room temperature,” Thin Solid Films, Vol. 236, pp. 1-5, 1993.
[16] H. L. Hartnagel, A.K. Jain and C. Jagadish, Semiconducting transparent thin films, Bristol: IOP, 1995.
[17] K. N. Tu, J. W. Mayer, and L. C. Feldman, Electronic thin film science (Macmillan, New York, 1992), Ch. 14.
[18] I. Hamada, and H. Katayama-Yoshida, “Energetic of native defects in CuAlO2,” Physica B, Vol. 376-377, pp. 808-811, 2006.
[19] L. J. Shi, Z. J. Fang, and J. Li, “First-principles study of p-type transparent conductive oxides CuXO2 (X=Y, Sc, and Al),” J. Appl. Phys., Vol. 104, p. 073527, 2008.
[20] C.K. Ghosh, D. Sarkar, M.K. Mitra and K.K. Chattopadhyay, “Electronic structure and optical properties of CuAlO2 under biaxial strain,” J. Phys.: Condens. Matter, Vol. 24, p. 235501, 2012.
[21] T. Ishiguro, N. Mizutani, and M. Kato, “A New Delafossite-Type Compound CuYO2,” J. Solid State Chem., Vol. 49, pp. 232-236, 1983.
[22] T. Ishiguro, N. Ishizawa, N. Mizutani, and M. Kato, “Single-crystal growth and crystal structure refinement of CuAlO2,” J. Solid State Chem., Vol. 40, pp. 170-174, 1981.
[23] H. Yanagi, S. Inoue, K. Ueda, H. Kawazoe, H. Hosono, and N. Hamada, “Electronic structure and optoelectronic properties of transparent p-type conducting CuAlO2,” J. Appl. Phys., Vol. 88, pp. 4159-4163, 2000.

[24] K.Tonooka, H. Bando, Y. Aiura, “Photovoltaic effect observed in transparent p-n heterojunctions based on oxide semiconductors,” Thin Solid Films, Vol. 455, pp. 327-331, 2003.
[25] X. G. Zheng, K. Taniguchi, A. Takahashi, Y. Liu, C. N. Xu, “Room temperature sensing of ozone by transparent p-type semiconductor CuAlO2,” Appl. Phys. Lett., Vol. 85, pp. 1728-1729, 2004.
[26] A. N. Banerjee, R. Maity, K. K. Chattopadhyay, “Preparation of p-type transparent conducting CuAlO2 thin films by reactive DC sputtering.”, Mater. Lett., Vol. 58, pp.10-13, Jan. 2004.
[27] A. N. Banerjee, C. K. Ghosh, K. K. Chattopadhyay, “Effect of excess oxygen on the electrical properties of transparent p-type conducting CuAlO2+x thin films,” Sol. Energy Mater. Sol. Cells, Vol. 89, pp. 75-83, 2005.
[28] W. Lan, W. L. Cao, M. Zhang, X. Q. Liu, Y. Y. Wang, E. Q. Xie, and H. Yan, “Annealing effect on the structural optical, and electrical properties of CuAlO2 films deposited by magnetron sputtering,” J. Mater. Sci., Vol. 44, pp.1594-1599, 2009.
[29] A. S. Reddy, P. S. Reddy, S. Uthanna, and G. M. Rao, “Characterization of CuAlO2 films prepared by dc magnetron sputtering,” J. Mater. Elec., Vol. 17, pp. 615-620, 2006.
[30] D. S. Kim, S. J. Park, E. K. Jeong, H. K. Lee, and S. Y. Choi, “Optical and electrical properties of p-type transparent conducting CuAlO2 thin film,” Thin solid films, Vol. 515, pp. 5103-5108, 2007.
[31] J. Tauc, R. Griogorovici, and A. Vaucu, “Optical Properties and Electronic Structure of Amorphous Germanium,” physica status solidi B, Vol. 15, pp. 627-637, 1966.
[32] L.Zhang, L. McMillon, and J. McNatt, “Gas-dependent bandgap and electrical conductivity of Cu2O thin films,” Sol. Energy Mater. Sol. Cells, Vol. 108, pp. 230-234, 2013.
[33] A. Gulino, P. Dapporto, P. Rossi, and I. Fragala, “A novel self-generating liquid MOCVD precursor for Co3O4 thin films,” Chem. Mater., Vol. 15, pp. 3748-3752, 2003.

[34] S. Fujuhara, Y. Ogawa, and A. Kasai, “Tunable visible photoluminescence from ZnO thin films through Mg-doping and annealing,” Chem. Mater., Vol. 16, pp. 2965-2968, 2004.
[35] S. B. Wang, C. H. Hsiao, S. J. Chang, K. T. Lam, K. H. Wen, S. C. Hung, S. J. Young, and B. R. Huang, “A CuO nanowire infrared photodetector,” Sens. Actuators A, Vol. 171, pp. 207-211, 2011.
[36] A. M. B. Goncalves, L. C. Campos, A. S. Ferlauto, and R. G. Lacerda, “On the growth and electrical characterization of CuO nanowires by thermal oxidation,” J. Appl. Phys., Vol. 106, p.034303, 2009.
[37] Y. Mao, J. He, X. Sun, W. Li, X. Lu, J. Gan, Z. Liu, L. Gong, J. Chen, P. Liu, and Y. Tong, “Electrochemical synthesis of hierarchical Cu2O stars with enhanced photoelectrochemical properties,” Electrrochim. Acta, Vol. 62, pp. 1-7, 2012.
[38] H. Solache-Carranco, G. Juarez-Diaz, A. Esparza-Garcia, M. Briseno-Garcia, M. Galvan-Arellano, J. Martinez-Juarez, G. Romero-Paredes, and R. Pena-Sierra, “Photoluminescence and X-ray diffraction studies on Cu2O,” J. Lumin., Vol. 129, pp. 1483-1487, 2009.
[39] H.Gao, J. Zhang, M. Li, K. Liu, D. Guo, and Y. Zhang, “Evaluating the electric property of different crystal faces and enhancing the Raman scattering of Cu2O microcrystal by depositing Ag on the surface,” Curr. Appl. Phys., Vol. 13, pp. 935-939, 2013.
[40] W. Lan, J. Q. Pan, C. Q. Zhu, G. Q. Wang, Q. Su, X. Q. Liu, E. Q. Xie, and H. Yan, “Role of oxygen in structural properties of annealed CuAlO2 films,” J. Cryst. Growth, Vol. 314, pp. 370-373, 2011.
[41] J. Pellicer-Porres, D. Martínez-García, A. Segura, P. Rodríguez-Hernández, A. Muñoz, J. C. Chervin, N. Garro, and D. Kim, “Pressure and temperature dependence of the lattice dynamics of CuAlO2 investigated by Raman scattering experiments and ab initio calculations,” Phys. Rev. B, Vol. 74, p. 184301, 2006.