臺灣博碩士論文加值系統

近年來，為了要增加太陽光的萃取，抗反射結構被廣泛的使用在各種太陽光伏元件上。在本論文中主要想利用抗反射結構去提升太陽電池的轉換效率。首先，為了要比較有無結構的差異性，使用無結構的異質接面太陽電池作為基準去探討。此外，藉由加入本質的非晶矽氫緩衝層，不僅可以抑制漏電流，也使得轉換效率有所提升。另一方面，為了要研究微結構對於太陽電池的影響。首先探討微結構的光學和表面特性。接著，利用微結構製作的異質接面太陽電池，其在光電流表現上有著顯著的提升，進而提升轉換效率。再者，藉由提升氧化銦錫透明導電層的成長溫度，太陽電池的填充因子也有所提升。最後探討背表面電場對於異質太陽電池的影響。

In the past few years, the anti-reflection structure was largely used in photovoltaic devices to enhance the light extraction. In order to improve the solar cell conversion efficiency, the anti-reflection structure is studied. The heterojunction solar cell without anti-reflection structure is fabricated for comparison. Besides, inserting intrinsic layer is a way to improve efficiency. The (p) a-Si/ (n) c-Si interface is passivated to reduce leakage current. On the other hand, the properties of textured structure are investigated including optical reflectance and surface morphology. The anti-reflection effect of textured structure is significant. By means of anti-reflection structure, the short circuit current density (Jsc) can be largely enhanced and the efficiency is improved. Next, the improvement of fill factor is facilitated by increasing the deposition temperature of indium tin oxide (ITO). Finally, the effect of back surface field (BSF) structure is studied on solar cell with anti-reflection structure.

Chapter 1 Introduction 1
1.1 Solar Energy 1
1.2 Brief History of Photovoltaic Devices 1
1.3 HIT Solar Cells 3
1.4 Motivation of the Research 4
1.5 Outlines of the Thesis 6
Chapter 2 Experiments 7
2.1 Fabrication equipment 7
2.1.1 Deposition System – PECVD 7
2.1.2 Sputter and Resistive thermal evaporation 12
2.2 Substrate Preparation 13
2.3 Deposition Procedures – PECVD 13
2.4 Measurement Techniques 15
2.4.1 Film Thickness 15
2.4.2 Surface characterization 16
2.4.3 Current – Voltage Characteristics 16
2.4.4 Transmittance and Reflectance 18
2.4.5 Spectral Response 18
2.4.6 Introduction of FTIR 20
Chapter 3 Properties of Hydrogenated Amorphous Silicon and HIT Solar Cells with Flat structure 23
3.1 Experiments 23
3.2 Results and Discussion 26
3.2.1 Structure Properties of a-Si:H 26
3.2.2 Optical Properties of a-Si:H 29
3.2.3 Electrical Properties of a Si:H 30
3.2.4 HIT Solar Cells without Buffer layer 33
3.2.4.1 The Fabrication of HIT Solar Cells without Buffer Layer……... ……………………………………………………………...33
3.2.4.2 Current-Voltage Characteristics 35
3.2.5 HIT Solar Cells with Buffer i Layer 40
3.2.5.1 The Fabrication Processes of HIT Solar Cells with Buffer i Layer …………………………………………………………………41
3.2.5.2 The I-V Characteristics of HIT Solar Cells with Buffer i Layer ……………………………………………………………...42
Chapter 4 HIT Solar Cells with Textured Structure 49
4.1 Improved Substrate using Texture Structure 49
4.1.1. The Fundamentals of Anti-reflection coating 49
4.1.2. Fabrication of Texture Substrate 50
4.1.3. Surface morphologies of Textured Substrate 51
4.1.4. Optical Properties of Textured Substrate 56
4.2. HIT Solar cell on Textured Substrate 59
4.2.1. HIT Solar Cells on Double-Textured Structure 59
4.2.1.1. The Fabrication Processes of HIT Solar cells with Double-textured structure…………………………………………… 59
4.2.1.2. Current-Voltage Characteristics 60
4.2.2. HIT Solar Cells on Single-Textured Structure 61
4.2.2.1.The Fabrication Process of HIT Solar cells with Single-Textured Structure ……………………………………………61
4.2.2.2.Current-Voltage Characteristics 62
4.2.3. The Optimization of a-Si:H(p) layer of HIT Solar Cells with the Textured Substrate 72
4.2.3.1. The fabrication process of HIT Solar Cells with textured substrate 72
4.2.3.2. Current-Voltage characteristics 72
4.3. The Improvements of HIT Solar Cells with the textured substrate 77
4.3.1. The Influence of Indium Tin Oxide on the Performance of HIT Solar cells 77
4.3.1.1. The Fabrication of Solar Cells with different ITO Deposition Temperature 78
4.3.1.2. Results and Discussion 78
4.3.2. The improvement of Textured Solar Cell by using BSF Structure 83
4.3.2.1. The Fabrication Processes of HIT Solar cells with BSF Structure 83
4.3.2.2. The characteristics of HIT Solar Cells with BSF Structure 84
4.4. The effect of anti-reflection structure 88
Chapter 5 Conclusions 90
References 92

[1]Zhao J, Wang A, Green M, “24‧5% Efficiency silicon PERT cells on MCZ substrates and 24‧7% efficiency PERL cells on FZ substrates” Prog. Photovolt. 7 471-474 (1999).
[2]Luque A, Ruiz J, Cuevas A, Agost M, “Double-sided solar cells to improve static concentration” Proc. 1st Euro. Conf. Photovoltaic Solar Energy Conversion, 269-277 (1977).
[3]Green M, “Silicon Solar cells Advanced Principles and Practice”, Chap. 7, Centre for Photovoltaic Devices and Systems, University of New South Wales, Sydney (1995).
[4]Tiedje T, Yablonovitch E, Cody G, Brooks B, “Limiting efficiency of silicon solar cells”, IEEE Trans, Electron Devices 31, 711-716 (1984).
[5]Waver P, Schmidt A, Wagemann H, Proc. 14th Euro, Conf, Photovoltaic Solar Energy Conversion , 2450-2453 (1997).
[6]Green M, “Silicon solar cells: at the crossroads”, Prog. Photovolt. 8, 443-450 (2000).
[7]Jianhua Zhao, “Recent advances of high-efficiency single crystalline silicon solar cells” , Sol. Energy Mater. Sol. Cells, 82,53 (2004)
[8]W. Fuhs , S. Gall, B. Rau, M. Schmidt, J. Schneider, “A novel route to a polycrystalline silicon thin-film solar cell” , Solar Energy 77, 961 (2004).
[9]B. Zimmermann, M. Glatthaar, M. Niggemann, M. Riede, A. Hinsch, “Electroabsorption studies of organic bulk-heterojunction solar cells” ,Thin Solid Films 493, 170-174 (2005)
[10] Q.L. Song, F.Y. Li, H. Yang, H.R. Wu, X.Z. Wang, W. Zhou, J.M. Zhao ,X.M. Ding, C.H. Huang, X.Y. Hou, “Small-molecule organic solar cells with improved stability” ,Chemical Physics Lett. 416,42-46 (2005).
[11]A.E. Becquerel, “Recherches sur les effets de la radiation chimique de la lumiere solaire au moyen des courants electriques” ,C. R. Acad. Sci. 9, 145 (1839).
[12]W.G. Adams and R.E. Day, “The Action of Light on Selenium” ,Proceedings of the Royal Society of London 25 (171-178), 113 (1876).
[13]M. A. Green, “Third generation photovoltaics: solar cells for 2020 and beyond” .Physica E (Amsterdam) 14, 65, (2002).
[14]Chapin D, Fuller C, Pearson G, “A New Silicon p‐n Junction Photocell for Converting Solar Radiation into Electrical Power” ,J. Appl. Phys. 25, 676, (1954).
[15]W.E. Spear and P.G. LeComber, “Substitutional doping of amorphous silicon” ,Solid State Comm., 17,1193 (1975).
[16]K. Wakisaka, M. Taguchi, T. Sawada, M. Tanaka, T. Matsuyama, T. Matsuoka, S. Tsuda, S. Nakano, Y. Kishi, and Y. Kuwano. “More than 16% solar cells with a new `HIT'' (doped a-Si/nondoped a-Si/crystalline Si) structure” ,Proceedings of the 22nd IEEE Photovoltaic Specialists Conference (IEEE-PVSC-22), Las Vegas, USA (1991).
[17]M. Tanaka, M. Taguchi, T. Matsuyama, T. Sawada, S. Tsuda, S. Nakano, H. Hanafusa, Y. Kuwano, “Development of New a-Si/c-Si Heterojunction Solar Cells: ACJ-HIT (Artificially Constructed Junction-Heterojunction with Intrinsic Thin-Layer)” ,Jpn. J. Appl. Phys., 31 (1992), pp. 3518–3522
[18]Mishima, T., Taguchi, M., Sakata, H., & Maruyama, E. “Development status of high-efficiency HIT solar cells” ,Sol. Energy Mater. Sol. Cells, 95, 18-21. (2011)
[19]M. A. Green, “Solar Cells: Operating Principles, Technology, and System
Applications” Prentice-Hall, New Jersey, (1982).
[20]M. Taguchi, K. Kawamoto, S. Tsuge, T. Baba, H. Sakata, M. Morizane, K. Uchihashi, N. Nakamura, S. Kiyama, and O. Oota, “HITTM cells—high-efficiency crystalline Si cells with novel structure” ,Prog. Photovoltaics 8, 503, (2000).
[21]P. Campbell , “Light trapping in textured solar cells” ,Sol. Energy Mater. Sol. Cells. 21, 165–172, (1990).
[22]P. Campbell, “Enhancement of light absorption from randomizing and geometric textures” , J. Opt. Soc.Am. B 10, 2410–2415, (1993)
[23]P. Campbell, M.A. Green, “High performance light trapping textures for monocrystalline silicon solar cells”, Sol. Energy Mater. Sol. Cells 65, 369–375, (2001).
[24]E. Vazsonyi, K. De Clercq, R. Einhaus, E. V. Kerschaver, K. Said,J. Poortmans, J. Szlufcik, and J. Nijs, “Improved anisotropic etching process for industrial texturing of silicon solar cells”, Sol. Energy. Mater. Sol. Cells, 57, 179, (1999).
[25]Q.-B. Vu, D. A. Stricker, and P. M. Zavracky, “Surface Characteristics of (100) Silicon Anisotropically Etched in Aqueous KOH”, J. Electrochem. Soc. 143, 1372, (1996).
[26]X. Li and P. W. Bohn, “Metal-assisted chemical etching in HF/H2O2 produces porous silicon”, Appl. Phys. Lett. 77, 2572, (2000)
[27]Yoo, K. Kim, M. Thamilselvan, N. Lakshminarayn, Y. K. Kim, J. Lee, K. J. Yoo, and J. Yi, “RIE texturing optimization for thin c-Si solar cells in SF6/O2 plasma”, J. Phys. D: Appl. Phys 41, 125205, (2008).
[28]Nayak, Barada K., Vikram V. Iyengar, and Mool C. Gupta. “Efficient light trapping in silicon solar cells by ultrafast-laser-induced self-assembled micro/nano structures” ,Progress in Photovoltaics: Research and Applications, 19, 631–639, (2011)
[29]F. Toor, H. M. Branz, M. R. Page, K. M. Jones, and H.-C. Yuan, “Multi-scale surface texture to improve blue response of nanoporous black silicon solar cells”, Appl. Phys. Lett. 99, 103501, (2011).
[30]H. M. Branz, V. E. Yost, S. Ward, K. M. Jones, B. To, and P. Stradins, “Nanostructured black silicon and the optical reflectance of graded-density surfaces”, Appl. Phys. Lett. 94, 231121 (2009).
[31]Dekkers HFW, Duerinckx D, Szlufcik J, Nijs J. “Silicon surface texturing by reactive ion etching”, Opto-Electronics Review, 8, 311–316, (2000).
[32]M. D. Abbott , P. J. Cousins , F. W. Chen and J. E. Cotter, “LASER-INDUCED DEFECTS IN CRYSTALLINE SILICON SOLAR CELLS”, Proc. 31st IEEE Photovolt. Spec. Conf., 1241 -1244 2005
[33]M. Abbott and J. Cotter, “Optical and electrical properties of laser texturing for high-efficiency solar cells”, Prog. Photovolt. 14, 225 (2006).
[34]S. Olibet, C. Monachon, A. Hessler-Wyser, E. Vallat-Sauvain, S. De Wolf, L. Fesquet, J. Damon-Lacoste, and C. Ballif, “Textured Silicon Heterojunction Solar Cells With Over 700 mV Open-Circuit Voltage Studied by Transmission Electron Microscopy”, Proceedings of the 23rd European Photovoltaic Solar Energy Conference, Valencia, Spain, (2008).
[35]G. Kumaravelu, M.M. Alkaisi, A. Bittar, D. Macdonald, J. Zhao, “Damage studies in dry etched textured silicon surfaces”, Curr. Appl. Phys., 4, 108, (2004).
[36]V.Y. Yerokhov, R. Hezel, M. Lipinski, R. Ciach, H. Nagel, A. Mylyanych, P. Panek,, “Cost-effective methods of texturing for silicon solar cells”, Sol. Energy Mater. Sol. Cells 72, 291–298, (2002).
[37]D.K. Schroder, “Semiconductor material and device characterization.” (Wiley-IEEE press, 2006).
[38]G. Nakamura, K. Sato, H. Kondo, Y. Yudimoto. And K. Shirahato, Eur, Community Photovoltaic Sol, Energy Conf. 4th Stressa. Italy, p616. D. Reidil, Doredrect, Holland. (1982)
[39]B. Akaoglu, K. Sel, I. Atilgan, and B. Katircioglu, “Carbon content influence on the optical constants of hydrogenated amorphous silicon carbon alloys”, Opt. Mater. 30, 1257 (2008)
[40]Veronika Vavrunkova , Jarmila Mu llerova , Rudolf Srnanek , Pavol S utta , ” Structural changes studies of a-Si:H films deposited by PECVD under different hydrogen dilutions using various experimental techniques”, Vacuum 84, 123–125 (2010)
[41]J. Tauc, R. Grigorovici, A. Vancu, “Optical Properties and Electronic Structure of Amorphous Germanium”, Phys. Stat. Sol. 15, 627, (1966).
[42]L. Korte , E.Conrad, H.Angermann, R.Stangl, M.Schmidt, “Advances in a-Si:H/c-Si heterojunction solar cell fabrication and characterization”, Sol. Energy Mater. Sol. Cells 93, 905–910, (2009).
[43]T. C. Chiou, and S. C. Lee, “a-Si:H/c-Si Heterojunction Solar Cells”, Graduate Institute of Electronics Engineering College of Electrical Engineering and Computer Science, National Taiwan University, Master Thesis
[44]E.D. Palik, O.J. Glembocki, I. Heard Jr., P.S. Burno, L. Tenerz, “Etching roughness for (100) silicon surfaces in aqueous KOH”, J. Appl. Phys. 70, 3291, (1991).
[45]M.A. Green, J. Zai, A. Wang, S.R. Wenham, “45% efficient silicon photovoltaic cell under monochromatic light”, IEEE Electr. Device Lett. 13, 317, (1992).
[46]H. Seidel, L. Csepregi, A. Heuberger, H. BaumgSrtel, “Anisotropic Etching of Crystalline Silicon in Alkaline Solutions I. Orientation Dependence and Behavior of Passivation Layers”, J. Electrochem. Soc., Vol. 137, 3612, (1990).
[47]H. Seidel, L. Csepregi, A. Heuberger, H. BaumgSrtel, “Anisotropic Etching of Crystalline Silicon in Alkaline Solutions II. Influence of Dopants”, J. Electrochem. Soc., Vol. 137, 3626, (1990).
[48]Toru Sawada, Norihiro Terada, Sadaji Tsuge, Toshiaki Baba, Tsuyoshi Takahama,
Kenichiro Wakisaka, Shinya Tsuda and Shoichi Nakano, ”HIGJ-EFFICIENCY a-Si/c-Si HETEROJUNCTION SOLAR CELL”, Photovoltaic Energy Conversion, 1994., Conference Record of the Twenty Fourth. IEEE Photovoltaic Specialists Conference-1994, 1994 IEEE First World Conference on. Vol. 2. IEEE, 1994.
[49]M.R. Page, E. Iwaniczko, Y. Xu, Q. Wang, Y. Yan, L. Roybal, Howard M. Branz, and T.H.Wang, ”Well Passivated a-Si:H Back Contacts for Double-Heterojunction Silicon Solar Cells”, Photovoltaic Energy Conversion, Conference Record of the 2006 IEEE 4th World Conference on. Vol. 2. IEEE, (2006).