本論文研究添加抗反射層(Anti-Reflection Coating, ARC) 對於利用金屬誘發橫向結晶(Metal Induced Lateral Crystallization, MILC)在玻璃基板上誘發成奈米晶矽/非晶矽複合式薄膜及網版印刷多晶矽太陽能電池轉換效率的影響。抗反射層含各種透明的導電氧化金屬如AZO、ITO、TiO2、ZnO及氮化矽。並藉由改變濺鍍角度沉積不同折射率與粗糙度的抗氧化層，以期達到最佳的效率提升。
在薄膜太陽電池的研究，吾人採用PECVD來沉積非晶矽於ITO玻璃上，再退火結晶奈米多晶矽，運用RF Sputtering鍍膜成長各種不同ARC層。在網印多晶矽太陽電池的研究，首先在P型矽基作磷擴散形成p/n介面，再利用網版印刷銀膠高溫燒結做金屬電極，然後濺鍍沉積不同的ARC完成太陽能電池。並以FE-SEM、AFM、Raman、XRD等儀器來分析薄膜結構，及利用Solar Simulation量測Isc、Voc、Fill Factor、efficiency等重要參數。
實驗結果顯示在薄膜太陽能電池添加ARC效果可提升百分之十的轉換效率。在網印多晶矽太陽電池以50度斜角濺鍍AZO，則可提升百分之三十七的轉換效率。此外吾人也發現ARC的折射率會隨著濺鍍斜角(離子的入射線與基板之間的夾角)的減少而降低，表面粗糙度則更增加。但大到某程度的時候則呈現相反的結果。如AZO由90度降到50度，折射率由2.05降到1.87；粗糙度由1.93nm升到3.11nm。但當角度的再降低到30度則折射率上升為2.03；粗糙度則降為1.85nm。ARC折射率降低可使空氣與太陽電池折射率更匹配得到最少的太陽光反射，進而提高轉換效率。本研究發現角度變化最高可提升約百分之五的轉換效率。
添加ARC後的非晶(奈米)矽薄膜及網印多晶矽太陽電池，經由標準光源AM1.5照射後所量測出來最佳特性，開路電壓=0.39V/0.52V、短路電流=6.55mA/283.49mA、填充因子=0.527/0.503、與轉換效率=1.348%/8.25%。

In this thesis, we study the effect of adding an anti-reflective coating (ARC) on conversion efficiency of the amorphous/ nano-crystalline Si composite thin film and the paste screen printing polycrystalline silicon solar cell in details. The thin film solar cell was prepared on glass substrate by the metal induced lateral crystallization (MILC) method on PECVD deposited amorphous Si film. And the paste screen printing polycrystalline silicon solar cell was manufactured by formation of n+ emitter on the p type poly base and use of screen printing and sintering silver paste for grid metal electrodes.
We use various transparent conductive metal oxides such as AZO, ITO, TiO2, ZnO and SiN as the ARC. The ARC layers were sputtered under various angles to change their refractive index and the roughness for achieving the best efficiency. In addition, FE-SEM, AFM, Raman, XRD were applied to analyze the ARC characteristics and used solar simulator to measure Isc, Voc, Fill Factor and efficiency.
Among these various ARC, we find the AZO is the best ARC material. Its refractive index and surface roughness are reduced and increased, respectively with the reduction of sputtering angle to 50 degree, and then getting an opposite result for continuous reduction. For example, as the angle is reduced from 90 degree to 50 degree the refractive index is down to 1.87 from 2.05, and roughness is raised to 3.11nm from the 1.93nm. But as the angle is down to 30 degree the refractive index increases to 2.03 and roughness reduces to 1.85.
The ARC with a smaller refractive index can lead the refractive index of solar cells to match that of air more, thus improving efficiency. For example, with the 50 degree sputtered AZO as ARC, efficiency of the thin film and the poly solar cells can be promoted 10 % and 37%, respectively.
In this study, the AZO coated amorphous/ nano-crystalline Si composite thin film and the paste screen printing polycrystalline silicon solar cell have the best performance of Voc = 0.39V and 0.52V, Isc = 6.55mA and 283.49 mA, Fill Factor = 0.527 and 0.503, and efficiency = 1.348% and 8.25% , respectively under AM1.5 sun power irradiation .

[1] T. Shimizu, "Staebler-Wronski Effect in Hydrogenated Amorphous Silicon and Related Alloy Films," Jpn. J. Appl. Phys., vol. 43, pp. 3257-3268, 2004.
[2] S. Guha, "Manufacturing Technology of Amorphous and Nanocrystalline Silicon Solar Cells," in Proceedings of the 14th International Workshop on the Physics of Semiconductor Devices, Mumbai, India, K.L. Narasimhan ed., IEEE, Los Alamitos, CA, 2007.
[3] K. Saito, M. Sano, H. Otoshi, A. Sakai, S. Okabe, K. Ogawa, "High Efficiency Large Area Solar Cells Using Microcrystalline Silicon," in:Proceedings of the 3rd World PVSEC, Osaka, 2003.
[4] J. D. Hwang, T. Y. Chi, J. C. Liu, C. Y. Kung and I. C. Hsein, "Silicon-Based Solar Cell Fabricated by Metal-Induced Lateral Crystallization of Amorphous Silicon Film," Jpn. J. Appl. Phys., vol. 45, pp. 7675-7676, 2006.
[5] S. F. Chen, Y. K. Fang, P. C. Lin, T. H. Lee, C. Y. Lin, C. S. Lin and T. H. Chou, "Improving Boron-Induced Retardation of Metal-Induced Lateral Crystallization Length by Hydrogen Treatment, " Jpn. J. Appl. Phys. vol. 44 pp. L1039-L1041, 2005.
[6] H. Kuriyama, T. Nohda, Y. Aya, T. Kuwahara, K. Wakisaka, S. Kiyama, and S. Tsuda, “Comprehensive Study of Lateral Grain Growth in Poly-Si Films by Excimer Laser Annealing and Its Application to Thin Film Transistors,” Japanese Journal of Applied Physics, vol. 33, pp. 5657-5662, 1994.
[7] A. Misumi, K. Sunahara, H. Tanabe, and M. Kumada, ” Evaporated polycrystalline-silicon thin-film transistors on glass,” IEEE UEDM Tech. Digest, pp.305, 1981.
[8] M. Matsui, “Low-temperature formation of polycrystalline silicon films by molecular beam deposition,” Journal of Applied Physics, vol. 53, p. 995, 1982.
[9] D.B. Meakin, P.A. Coxon, P. Migliorato, J. Stoemenos, and N.A. Economou, “High-performance thin-film transistors from optimized polycrystalline silicon films,” Applied Physics Letters, vol. 50, p. 1894, 1987.
[10] W. Schmolla, J. Diefenbach, G. Blang, W. Senske, ” POLY-SILICON DEPOSITION BY EVAPORATION FOR TFTs,” Mat. Res. Symp. Proc., vol.106, pp.329, 1988.
[11] T. Baba, T. Matsuyama, T. Sawada, T. Takahama, K. Wakisaka, S. Tsuda, S. Nakano, “Polycrystalline silicon thin-film solar cell prepared by the solid phase crystallization (SPC) method,” 1994 IEEE, First WCPEC, Dec. 5-9, Hawaii, pp.1315-1318, 1994.
[12] T. Matusuyama, K. Wakisaka, M. Kameda, M. Tanaka, T. Matsuoka, S. Tsuda, S. Nakano, Y. Kishi, and Y. Kuwano, Preparation of High-Quality n-Type Poly-Si Films by the Solid Phase Crystallization(SPC) Method , Jpn. J. Appl. Phys., Vol.29, pp.2327-2331
[13] M. Miyasaka and J. Stoemenos, “Excimer laser annealing of amorphous and solid-phase-crystallized silicon films,” Journal of Applied Physics, vol. 86, p. 5556, 1999.
[14] P. Lengsfeld, N.H. Nickel, and W. Fuhs, “Step-by-step excimer laser induced crystallization of a-Si:H,” Applied Physics Letters, vol. 76, p. 1680, 2000.
[15] R. Y. Yang, M. H. Weng, C. T. Liang, Y. K. Su and S. L. Shy, “Low Temperature Metal Induced Crystallization of Amorphous Silicon by Nano-Gold-Particles”, Japanese Journal of Applied Physics, Vol.45, No.43, pp.L1146-L1148, 2006
[16] S. F. Chen, Y. K. Fang, W. D. Wang, C. Y. Lin and C. S. Lin, “Low temperature grown poly-SiGe thin film by Au metal-induced lateral crystallization with fast MILC growth rate”, Electronics Letters, Vol.39, No.22, 30 October 2003
[17] Y. T. Chiang, Y. K. Fang, K. C. Lin, T. H. Chou and S. F. Chen, “The Effect of H-Treatment on Au-Induced Lateral Crystallization of Phosphorus-Doped a-Si:H Films”, Electrochemical and Solid-State Letters, Vol.10, No.8, pp. H221-H223, 2007
[18] C. F. Cheng, M. C. Poon, C. W. Kok, Mansun Chan, “Modeling of Metal-Induced-Lateral-Crystallization Mechanism for Optimization of High Performance Thin-Film-Transistor Fabrication”, IDEM, pp.569-572, 2002
[19] K.N. Tu, “Selective growth of metal-rich silicide of near-noble metals,” Applied Physics Letters, vol. 27, p. 221, 1975.
[20] M.S. Ashtikar and G.L. Sharma, “Silicide mediated low temperature crystallization of hydrogenated amorphous silicon in contact with aluminum,” Journal of Applied Physics, vol. 78, p. 913, 1995.
[21] Y. Masaki, T. Ogata, H. Ogawa, and D.I. Jones, “Kinetics of solid phase interaction between Al and a-Si:H,” Journal of Applied Physics, vol. 76, p. 5225, 1994.
[22] L. Hultman, A. Robertsson, H.T.G. Hentzell, I. Engström, and P.A. Psaras, “Crystallization of amorphous silicon during thin-film gold reaction,” Journal of Applied Physics, vol. 62, p. 3647, 1987.
[23] K. Lee, Y. Fang, and S. Fan, “Au metal-induced lateral crystallisation (MILC) of hydrogenated amorphous silicon thin film with very low annealing temperature and fast MILC rate,” Electronics Letters, vol. 35, pp. 1108-1109, Jun. 1999.
[24] J. Hyeok Kim and J. Yong Lee, “Al-Induced Crystallization of an Amorphous Si Thin Film in a Polycrystalline Al/Native SiO2/Amorphous Si Structure,” Japanese Journal of Applied Physics, vol. 35, pp. 2052-2056, 1996.
[25] O. Nast, T. Puzzer, L.M. Koschier, A.B. Sproul, and S.R. Wenham, “Aluminum-induced crystallization of amorphous silicon on glass substrates above and below the eutectic temperature,” Applied Physics Letters, vol. 73, p. 3214, 1998.
[26] G. Radnoczi, A. Robertsson, H.T.G. Hentzell, S.F. Gong, and M. Hasan, “Al induced crystallization of a-Si,” Journal of Applied Physics, vol. 69, p. 6394, 1991.
[27] O. Nast and A.J. Hartmann, “Influence of interface and Al structure on layer exchange during aluminum-induced crystallization of amorphous silicon,” Journal of Applied Physics, vol. 88, p. 716, 2000.
[28] M. Shahidul Haque, H.A. Naseem, and W.D. Brown, “Interaction of aluminum with hydrogenated amorphous silicon at low temperatures,” Journal of Applied Physics, vol. 75, p. 3928, 1994.
[29] Z. Jin, G.A. Bhat, M. Yeung, H.S. Kwok, and M. Wong, “Nickel induced crystallization of amorphous silicon thin films,” Journal of Applied Physics, vol. 84, p. 194, 1998.
[30] S.Y. Yoon, K.H. Kim, C.O. Kim, J.Y. Oh, and J. Jang, “Low temperature metal induced crystallization of amorphous silicon using a Ni solution,” Journal of Applied Physics, vol. 82, p. 5865, 1997.
[31] M. Miyasaka, K. Makihira, T. Asano, E. Polychroniadis, and J. Stoemenos, “In situ observation of nickel metal-induced lateral crystallization of amorphous silicon thin films,” Applied Physics Letters, vol. 80, p. 944, 2002.
[32] T. Itoh, K. Yamamoto, K. Ushikoshi, S. Nonomura, S. Nitta, “Characterization and role of hydrogen in nc-Si:H”, Journal of Non-Crystalline Solids 266-269 201-205, 2003
[33] C. Godet, N. Layadi, P. Roca I Cabarrocas, “Role of mobile hydrogen in the amorphous silicon recrystallization”, Applied Physics Letter Vol.66, No.23, 5 June 1995
[34] P. Roca I Cabarrocas, “Plasma enhanced chemical vapor deposition of amorphous, polymorphous and microcrystalline silicon films”, Journal of Non-Crystalline Solids 266-269, 31-37, 2000
[35] O. Kluth, B. Rech, L. Houben, S. Wieder, G. Schöpe, C. Beneking, H. Wagner, A. Löffl, and H.W. Schock, “Texture etched ZnO:Al coated glass substrates for silicon based thin film solar cells,” Thin Solid Films, vol. 351, pp. 247-253, Aug. 1999.
[36] H. Sato, T. Minami, Y. Tamura, S. Takata, T. Mouri, and N. Ogawa, “Aluminium content dependence of milky transparent conducting ZnO:Al films with textured surface prepared by d.c. magnetron sputtering,” Thin Solid Films, vol. 246, pp. 86-91, Jun. 1994.
[37] J. Kim and W. A. Anderson, “Metal silicide-mediated microcrystalline silicon thin-film growth for photovoltaics”, Solar Energy Materials & Solar cells 91 534-538, 2007
[38] H. Kim, D. Kim, G. Lee, D. Kim, and S.H. Lee, “Polycrystalline Si films formed by Al-induced crystallization (AIC) with and without Al oxides at Al/a-Si interface” , Solar Energy Materials and Solar Cells 74, pp. 323-329, 2002
[39] O. Ebil, R. Aparicio, R. Birkmire, “Aluminum-induced crystallization of amorphous silicon films deposited by hot wire chemical vapor deposition on glass substrates” , Thin Solid Films 519, pp. 178-183, 2010
[40] Q. Chen, X. Zeng, Y. Zeng, L. Liu, “Study on performance of p-Si thin film fabricated by aluminum induced lateral crystallization at low temperature” , Photonics and Optoelectronics Meetings : Solar Cells, Solid State Lighting, and Information Display Technologies, 2009
[41] Z. Jin, G. A. Bhat, M. Yeung, H. S. Kwok and M. Wong, “Nickel induced crystallization of amorphous silicon thin films”, J. Appl. Phys., Vol.84, No.1, 1 July 1998
[42] J.K. Kim, S. Chhajed, M.F. Schubert, E.F. Schubert, A.J. Fischer, M.H. Crawford, J. Cho, H. Kim , C. Sone, “Light-Extraction Enhancement of GaInN Light-Emitting Diodes by Graded-Refractive-Index Indium Tin Oxide Anti-Reflection Contact”, Adv. Mater. 20, pp. 801-804, JAN 2008