臺灣博碩士論文加值系統

本篇論文中，主要運用非晶矽薄膜排列，形成具有雙面射極之雙面照光異質結構光太陽能電池，以利用雙面照光的特性達成高轉換效率的太陽能電池。我們提出雙面對稱與交叉射極之雙面照光異質單晶矽太陽能電池(Double-sided Symmetrical and Crossed Emitter Bifacial Crystalline Silicon Solar Cells with Heterojunction)。在雙面照光的情況下，光子主要聚集於基板之正面與背面的表面，因此在本篇論文中，我們提出雙面主動層的架構，藉此減少少數載子電洞移動路徑，降低串聯電阻，提升載子吸收能力。在一般環境中，反射光可提供相當於正面太陽入射光之20 ~ 30 %的能量，因此我們設計出一個雙面照光的架構，能加以利用反射光。雙面照光太陽能電池的峰值區段為兩段，可拉長峰值時間，進而解決峰值輸出功率過剩的問題，此外，雙面照光太陽能電池因背部金屬電極佔面積比較低，因此太陽能電池在長時間運作下，溫度會比單面照光太陽能電池低。本論文將探討影響太陽能電池短路電流、開路電壓、填充因子以及轉換效率的主要原因。舉例:非晶矽薄膜比例、基板厚度對雙面照光影響、基板濃度、電場方向、電子電洞濃度分布以及雙面照光應用。
由模擬結果得知，我們的新式雙面交指式太陽能電池在背部光源為30 %的情況下，對稱型架構因雙面大面積主動層之原故使得短路電流密度可達到47.42 mA/cm2，使得轉換效率達到29.72 %，與傳統IBC太陽能電池相比短路電流密度上升了14.2 %，轉換效率上升了16.1 %。交叉型架構因電場推動少數載子填充因子可達84.34 %，使得轉換效率達到29.81 %，與傳統IBC太陽能電池相比，轉換效率上升了16.4 %。

In this thesis, we proposed the symmetrical and crossed bifacial crystalline silicon solar cell with heterojunction by using double-sided emitter. In the bifacial condition, most of the carriers gather in the front and back surface. In order to reduce the moving distance of these carriers, we propose a double-sided emitter structure which can decrease series resistance and improve the absorptive ability. In the general environment, the reflected light has 20 ~ 30 % illumination of the front incident light. We want to design a double-sided emitter structure which can use this reflected light completely. In the bifacial condition, most of the photons gathered in the front and back side surface. The double side emitter layer can reduce the moving distance of minority carriers which can reduce the recombination rate. Moreover, the conventional mono-facial solar cell has the excess output power problem in the peak area due to the limit of energy storage system. However, the bifacial solar cell has two peaks of maximum output power which can solve the problem in the above. In the following, we are going to talk about what are the main reasons which influence short-circuit current, open-circuit voltage, fill factor and power conversion efficiency. For instance, ratio of emitter and BSF, substrate thickness, substrate doping concentration, electric field direction, the density of electrons and holes and bifacial application.
By using Silvaco TCAD Atlas to calibrate and simulate, we found that the symmetrical structure solar cell can reach 47.42 mA/cm2 of short-circuit current and 29.72 % of conversion efficiency due to the double side large area emitter which are better than the conventional IBC for 14.2 % and 16.1 % respectively. The crossed structure can reach 84.34 % of fill factor and 29.81 % conversion efficiency due to the surrounding electric field. The conversion efficiency of the crossed structure is better than the conventional IBC for 16.4 %.

中文審定書 i
英文審定書 ii
致 謝 iii
摘 要 iv
Abstract v
目 錄 vi
圖 次 viii
表 次 xii
第一章 導論 1
1.1. 研究背景 1
1.2. 單晶矽太陽能電池探討 3
1.3. 動機 9
第二章 元件製作 11
2.1. 元件模擬 11
2.1.1. 雙面對稱與交叉式主動層太陽能電池模擬 11
2.1.2. 模擬之物理模型與參數 12
2.2. 元件製程 14
2.2.1. 雙面交叉主動層太陽能電池 14
2.2.2. 製程與不鏽鋼遮罩設計 14
第三章 元件操作機制 18
3.1. 太陽電池基本原理 18
3.1.1. 理想太陽電池等效電路 18
3.1.2. 實際太陽電池等效電路等效電路 19
3.2. 太陽能電池的基本參數介紹 21
3.2.1. 短路電流(Short circuit current, JSC) 21
3.2.2. 開路電壓(Open circuit voltage, Voc) 21
3.2.3. 最大功率點(Maximum power point, Pm) 22
3.2.4. 填充因子(Fill Factor, FF) 22
3.2.5. 轉換效率(Power Conversion Efficiency, ŋ) 22
第四章 元件設計與模擬 23
4.1. 傳統IBC太陽能電池模擬 24
4.2. 雙面對稱主動層太陽能電池(Double-sided Symmetrical Emitter Solar cell) 28
4.2.1. 元件結構說明 28
4.2.2. 非晶矽薄膜比例最佳化 29
4.2.3. 基板厚度最佳化 33
4.2.4. 金屬電極佔面積比最佳化 40
4.2.5. 基板摻雜濃度優化 40
4.3. 雙面交叉主動層太陽能電池(Double-sided Crossed Emitter Solar cell) 48
4.3.1. 元件結構說明 48
4.3.2. 非晶矽薄膜比例最佳化 50
4.3.3. 基板厚度最佳化 54
4.3.4. 電場探討 54
4.4. 各類架構探討 57
4.4.1. 改良式雙面HIT太陽能電池(Bifacial HIT Solar Cell, Bi-HIT) 57
4.4.2. 雙面照光比較 59
4.4.3. 異質接面探討 65
4.5. 實驗量測結果與討論 68
4.5.1. 單面照光 68
4.5.2. 雙面照光 69
4.5.3. 邊際效應比較 70
第五章 結論與未來展望 72
5.1. 結論 72
5.2. 未來展望 73
參考文獻 74
論文著述 80

[1]Grand View Research Inc., “Solar Cell Market Analysis, Market Size, Application Analysis, Regional Outlook, Competitive Strategies and Forecasts, 2015 to 2022,” Grand View Research, pp. 5-79, Jan. 2016.
[2]T. Dullweber and J. Schmidt, “Industrial Silicon Solar Cells Applying the Passivated Emitter and Rear Cell (PERC) Concept—A Review,” IEEE J. Photovoltaics, vol. 6, no. 5, pp. 1366-1381, Sep. 2016.
[3]M. Taguchi, A. Yano, S. Tohoda, K. Matsuyama, Y. Nakamura, T. Nishiwaki, K. Fujita, and E. Maruyama, “24.7 % Record Efficiency HIT Solar Cell on Thin Silicon Wafer,” IEEE J. Photovoltaics, vol. 4, no. 1, pp. 96-99, 2013.
[4]K. Masuko, M. Shigematsu, T. Hashiguchi, D. Fujishima, M. Kai, N. Yoshimura, T. Yamaguchi, Y. Ichihashi, T. Mishima, N. Matsubara, T. Yamanishi, T. Takahama, M. Taguchi, E. Maruyama, and S. Okamoto, “Achievement of More Than 25 % Conversion Efficiency with Crystalline Silicon Heterojunction Solar Cell,” IEEE J. Photovoltaics, vol. 4, no. 6, pp. 1433-1435, Nov. 2014.
[5]Photovoltaics and Thin Film Electronics Laboratory. (2017. May). Silicon-based heterojunction solar cells. Available:http://pvlab.epfl.ch/heterojunction_solar_cells
[6]M. Wolf and L. Ralph, “Effect of Thickness on Short-Circuit Current of Silicon Solar Cells,” IEEE Trans. Electron Devices, vol. 12, no. 8, pp. 470-474, Aug. 1965.
[7]Solar Cells, 2rd ed., Wu-nan Culture Enterprise Co., 2008., pp. 108-127
[8]N. Dwivedi, S. Kumar, A. Bisht, K. Patel and S. Sudhakar, “Simulation Approach for Optimization of Device Structure and Thickness of HIT Solar Cells to Achieve ~ 27 % Efficiency,” Solar Energy, vol. 88, pp. 31-41, Feb. 2013.
[9]M. Rudiger, H. Steinkemper, M. Hermle and S. W. Glunz, “Numerical Current Density Loss Analysis of Industrially Relevant Crystalline Silicon Solar Cell Concepts,” IEEE J. Photovoltaics, vol. 4, no. 2, pp. 533-539, Mar. 2014.
[10]L. Zhang, U. K. Das, Z. Shu, H. Liu, R. W. Birkmire and S. S. Hegedus, “Experimental and Simulated Analysis of p a-Si:H Defects on Silicon Heterojunction Solar Cells: Trade-offs between Voc and FF,” in IEEE 42th Photovoltaic Specialist Conference, 2015., pp. 1-5
[11]Z. Xin, S. Duttagupta, M. Tang, Z. Qiu, B. Liao, A. Aberle and R. Stangl, “An Improved Methodology for Extracting the Interface Defect Density of Passivated Silicon Solar Cells,” IEEE J. Photovoltaics, vol. 6, no. 5, pp. 1080-1089, Sep. 2016.
[12]E. Cho, Y. Ok, A. D. Upadhyaya, M. J. Binns, J. Appel and J. Guo, “P-Type Indium-Doped Passivated Emitter Rear Solar Cells (PERC) on Czochralski Silicon Without Light-Induced Degradation,” IEEE J. Photovoltaics, vol. 6, no. 4, pp.795-800, Jul. 2016.
[13]A. Descoeudres, Z. C. Holman, L. Barraud, S. Morel, S. D. Wolf, and C. Ballif, “> 21 % Efficient Silicon Heterojunction Solar Cells on n- and p-type Wafers Compared,” IEEE J. Photovoltaics, vol. 3, no. 1, pp. 83-89, Jan. 2013.
[14]M. Edwards, S. Bowden, U. Das, and M. Burrows, “Effect of Texturing and Surface Preparation on Lifetime and Cell Performance in Heterojunction Silicon Solar Cells,” Solar Energy Materials and Solar Cells, vol. 92, no. 11, pp. 1373-1377, 2008.
[15]K. Nakamura, M. Aoki, I. Sumita, H. Sato, Y. Kumagai, Y. Kawata, and Y. Ohshita, “Texturization Control for Fabrication of High Efficiency Mono Crystalline Si Solar Cell,” in IEEE 39th Photovoltaic Specialists Conference, 2013., pp. 2239-2242
[16]I. Martin, D. Munoz, C. Voz; M. Vetter, R. Alcubilla, J. Damon-Lacoste, P. R. I. Cabarrocas, F. Villar, J. Bertomeu and J. Andreu, “Comparison of (n+) a-Si:H / (p) c-Si Heterojunction Emitters Using a-Si:H Films Deposited by PECVD or HWCVD,” in IEEE 4th World Conference on Photovoltaic Energy Conference, 2006., pp. 1091-1094
[17]U. Das, S. Hegedus, L. Zhang, J. Appel, J. Rand and R. Birkmire, “Investigation of Hetero-interface and Junction Properties in Silicon Heterojunction Solar Cells”, in IEEE 35th Photovoltaic Specialist Conference, 2010., pp. 1358-1362
[18]R. Lachaume, J. Coignus, X. Garros, P. Scheiblin, F. De Crécy, D. Muñoz, and G. Reimbold, “Impact of Bulk Defects in Hydrogenated Amorphous Si Layers on Performance of High-efficiency Heterojunctions Solar Cells Assessed by 2D Modelling,” in IEEE 13th International Conference on Ultimate Integration on Silicon, 2012., pp. 97-100
[19]Y. Hayashi, L. Debin, A. Ogura, and Y. Ohshita, “Role of i-a-Si:H Layers in a-Si:H/c-Si Heterojunction Solar Cells,” IEEE J. Photovoltaics, vol. 3, no. 4, pp. 1149-1155, Oct. 2013.
[20]W. Favre, J. Coignus, N. Nguyen, R. Lachaume, R. Cabal, and D. Muñoz, “Influence of the Transparent Conductive Oxide Layer Deposition Step on Electrical Properties of Silicon Heterojunction Solar Cells,” Applied Physics Letters, vol. 102, no. 18, pp. 181118, 2013.
[21]S. M. Iftiquar, Y. Lee, V. A. Dao, S. Kim and J. Yi, “High Efficiency Heterojunction with Intrinsic Thin Layer Solar Cell: A Short Review,” Materials and processes for energy: communicating current research and technological developments, vol.1, no. 2, pp. 59-67, 2013.
[22]Z. C. Holman, A. Descoeudres, L. Barraud, F. Zicarelli, J. Seif, S. De Wolf and C. Ballif, “Current Losses at the Front of Silicon Heterojunction Solar Cells,” IEEE J. Photovoltaics, vol. 2, no. 1, pp. 7-15, Jan. 2012.
[23]B. Shu, U. Das, L. Chen, L. Zhang, S. Hegedus, and R. Birkmire, “Design of Anti-reflection Coating for Surface Textured Interdigitated Back Contact Silicon Hetero-junction Solar Cell,” in IEEE 38th Photovoltaic Specialists Conference, 2012., pp. 002258-002262
[24]M. Filipič, F. Smole and M. Topič, “Optimization of Interdigitated Back Contact Geometry in Silicon Heterojunction Solar Cell,” in IEEE 14th Numerical Simulation of Optoelectronic Devices Conference, 2014., pp. 161-162
[25]P. Magnone, M. Debucquoy, D. Giaffreda, N. Posthuma and C. Fiegna, “Understanding the Influence of Busbars in Large-Area IBC Solar Cells by Distributed Spice Simulations,” IEEE J. Photovoltaics, vol. 5, no. 2, pp. 552-558, Mar. 2015.
[26]I. Cesar, N. Guillevin, A. R. Burgers, A. A. Mewe, M. Koppes, J. Anker, L. J. Geerligs, and A. W. Weeber, “Mercury: A Back Junction Back Contact Front Floating Emitter Cell with Novel Design for High Efficiency and Simplified Processing,” Energy Procedia, vol. 55, pp. 633-642, 2014.
[27]A. R. Burgers, N. Guillevin, A. A. Mewe, A. Suvvi, P. Spinelli, A. W. Weeber and I. Cesar, “FFE IBC cells: Impact of Busbars on Cell Performance with Circuit Modelling,” in 5th International Conference on Silicon Photovoltaics, vol. 77, Aug. 2015., pp. 21-28
[28]A. R. Burgers, I. Cesar, N. Guillevin, A. A. Mewe, P. Spinelli and A. W. Weeber, “Designing IBC Cells with FFE: Long Range Effects with Circuit Simulation,” in IEEE 43th Photovoltaic Specialists Conference, Jun. 2016., pp. 2408-2411
[29]J.-B. Heng, J. Fu, B. Kong, Y. Chae, W. Wang, Z. Xie, A. Reddy, K. Lam, C. Beitel, C. Liao, C. Erben, Z. Huang and Z. Xu, “> 23 % High-Efficiency Tunnel Oxide Junction Bifacial Solar Cell with Electroplated Cu Gridlines,” IEEE J. Photovoltaics, vol. 5, no. 1, pp. 82-86, Jan. 2015.
[30]P. Stradins, S. Essig, W. Nemeth, B.G. Lee, D. Young, A. Norman, Y. Liu, J-W. Luo, E. Warren, A. Dameron, V. LaSalvia and M. Page, “Passivated Tunneling Contacts to N-Type Wafer Silicon and Their Implementation into High Performance Solar Cells,” WCPEC-6, vol. NREL/CP-5J00-63259, no.5, pp. 1-4, Dec. 2014.
[31]S. Duttagupta, Z. Hameiri, T. Grosse, D. Landgraf, B. Hoex, and A. G. Aberle, “Dielectric Charge Tailoring in PECVD SiOx/SiNx and Application at the Rear of Al Local Back Surface Field Solar Cells,” IEEE J. Photovoltaics, vol. 5, no. 4, pp. 1014-1019, 2015.
[32]H. Kima, S. Baea, K. Jib, S. M. Kima, J. W. Yanga, C. H. Leea, K. D. Leea, S. Kima, Y. Kangc, H. Leea and D. Kima, “Passivation Properties of Tunnel Oxide Layer in Passivated Contact Silicon Solar Cells,” Applied Surface Science, vol. 409, no. 9, pp. 140-148, Jul. 2017.
[33]K. M. Gad, D. Vössing, P. Balamou, D. Hiller, B. Stegemann, H. Angermann and M. Kasemann, “High Quality Tunneling Oxides for Passivated Contacts and Heterojunctions for High Efficiency Silicon Solar Cells,” in IEEE 42th Photovoltaic Specialist Conference, Jun. 2015., pp. 1-6.
[34]J. Stuckelberger, G. Nogay, P. Wyss, M. Lehmann, C. Allebé, F. Debrot, M. Ledinsky, A. Fejfar, M. Despeisse, F.-J. Haug, P. Löper and C. Ballif, “Passivating Contacts for Silicon Solar Cells with 800 °C Stability Based on Tunnel-Oxide and Highly Crystalline Thin Silicon Layer,” in IEEE 43th Photovoltaic Specialists Conference, Jun. 2016., pp. 2531-2535
[35]L. Mazzarella, S. Kolb, Simon Kirner, S. Calnan, L. Korte, B. Stannowski, B. Rech and R. Schlatmann, “Optimization of PECVD Process for Ultra-thin Tunnel SiOx Film as Passivation Layer for Silicon Heterojunction Solar Cells,” in IEEE 43th Photovoltaic Specialists Conference, Jun. 2016., pp. 2955-2959
[36]W.-Q. Xie, W.-F. Liu, J.-I. Oh, and W.-Z. Shen, “Optical Absorption in c-Si/a-Si:H Core/Shell Nanowire Arrays for Photovoltaic Applications,” Applied Physics Letters, vol. 99, no. 3, p. 033107, 2011.
[37]K. Nakamura, M. Aoki, I. Sumita, H. Sato, Y. Kumagai, Y. Kawata and Y. Ohshita, “Texturization Control for Fabrication of High Efficiency Mono Crystalline Si Solar Cell,” in IEEE 39th Photovoltaic Specialists Conference, vol. 99, 2011., pp. 2239-2242
[38]C. Cañizo, A. Moehlecke, I. Zanesco, I. Tobías and A. Luque, “Analysis of a Technology for CZ Bifacial Solar Cells,” IEEE Trans. Electron Devices, vol. 48, no. 10, pp. 2337-2341, Oct. 2001.
[39]D. M. Powell, M. T. Winkler, H. J. Choi, C. B. Simmons, D. B. Needleman and T. Buonassisi, “Crystalline Silicon Photovoltaics: A Cost Analysis Framework for Determining Technology Pathways to Reach Baseload Electricity Costs,” Energy Environ. Sci., vol. 5, no. 3, pp. 5874-5883, Mar. 2012.
[40]A. Kalio, A. Richter, C. Schmiga, M. Glatthaar and J. Wilde, “Study of Dielectric Layers for Bifacial n-type Silicon Solar Cells with Regard to Optical Properties, Surface Passivation Quality, and Contact Formation,” IEEE J. Photovoltaics, vol. 4, no. 2, pp. 575-580, Mar. 2014.
[41]N. T. Rottol, S. R. Meyerl, M. Votaval and D. L. Meier, “Cu Backside Busbar Tape: Eliminating Ag and Enabling Full Al Coverage in Crystalline Silicon Solar Cells and Modules,” in IEEE 42th Photovoltaic Specialist Conference, Jun. 2015., pp. 1-6
[42]Z.-J. Yu, K. C. Fisher, B. M. Wheelwright, R. P. Angel and Z. C. Holman, “PV Mirror: A New Concept for Tandem Solar Cells and Hybrid Solar Converters,” IEEE J. Photovoltaics, vol. 5, no. 6, pp. 1797-1799, Nov. 2015.
[43]R. Guerrero-Lemus, R. Vega, T. Kim, A. Kimm, and L. E. Shephard, “Bifacial Solar Photovoltaics – A Technology Review,” Renewable and Sustainable Energy Reviews, vol. 60, pp. 1533-1549, Jul. 2016.
[44]J. Wong, S. Raj, J. W. Ho, J. Wang and J. Lin, “Voltage Loss Analysis for Bifacial Silicon Solar Cells: Case for Two-Dimensional Large-Area Modeling,” IEEE J. Photovoltaics, vol. 6, no. 6, pp. 1421-1426, Nov. 2016.
[45]Neo., “Mono-crystal Photovoltaic Module,” NEO SOLAR POWER, 2016.
[46]J. Rodriguez (2015, May 5). Bifacial solar cells – the two sides of the story. Available:https://www.solarchoice.net.au/blog/news/bifacial-solar-cells-the-two-sides-of-the-story-050515
[47]J. N. Mayer, S. Philipps, N. S. Hussein, T. Schlegl and C. Senkpiel, “Current and Future Cost of Photovoltaics,” Long-term Scenarios for Market Development, System Prices and LCOE of Utility-Scale PV Systems (Fraunhofer ISE, Study on behalf of Agora Energiewende, 2015.
[48]Silvaco, Inc. Atlas User’s Manual Device Simulation Software Available: www.silvaco.com
[49]J. L. Herna´ndez, K. Yoshikawa, A. Feltrin, N. Menou, N. Valckx, E. V. Assche, D. Schroos, K. Vandersmissen, H. Philipsen, J. Poortmans, D. Adachi, M. Yoshimi, T. Uto, H. Uzu, T. Kuchiyama, C. Allebe´, N. Nakanishi, T. Terashita, T. Fujimoto, G. Koizumi and K. Yamamoto, “High Efficiency Silver-Free Heterojunction Silicon Solar Cell,” Japanese Journal of Applied Physics, vol. 51, no. 10s, pp. 3644-3648, Oct. 2012.
[50]J.-Y. Wang (2013), “A Cd-free and ZnS based CIGS Solar Cell with a Wide-Bandgap InGaP Secondary Layer,” M.S., Department of Electrical Engineering, National Sun Yat Sen University, Kaohsiung.
[51]J.-W. Chen (2009), “The Simulation and Studies of the Large Area Organic Solar Cells,” M.S., Institute of Electronics Engineering, National Tsing Hua University, Hsinchu.
[52]K. Yoshikawa, H. Kawasaki, W. Yoshida, T. Irie, K. Konishi, K. Nakano, T. Uto, D. Adachi, M. Kanematsu, H. Uzu, and K. Yamamoto, “Silicon Heterojunction Solar Cell with Interdigitated Back Contacts for a Photo-conversion efficiency over 26 %,” Nature Energy, vol. 2, no. 5, p. 17032, 2017.
[53]M. Filipič, F. Smole and M. Topič, “Optimization of Interdigitated Back Contact Geometry in Silicon Heterojunction Solar Cell,” NUSOD, pp. 161-162, Sep. 2014.
[54]Solarzoom (2013, May). 高效率HIT太陽能電池的發展現, Available: http://www.solarzoom.com/article-29437-1.html
[55]L. v. Dijk, U. W. Paetzold, G. A. Blab, E. A. P. Marcus, A. J. Oostra, J. v. d. Groep, A. Polman, R. E. I. Schropp, and M. D. Vece, “3D-printed External Light Traps for Solar Cells,” in 2015 IEEE 42th Photovoltaic Specialist Conference, 2015., pp. 1-3
[56]C. Hammerschmidt (2016, June). Solar Cells with High Bifaciality Developed, Available:http://www.eenewseurope.com/news/solar-cells-high-bifaciality-developed