本實驗研究硼酸之脫水機制，利用TGA分析，改善預烤升溫方式以增加硼擴散源之使用率，將研究成果利用旋轉塗佈摻雜(Spin on dopants, SOD)方式，藉由兩次高溫擴散驅使外加載子(硼及磷)擴散進入矽晶格形成電池射極 (Emitter) 與背表面電場 (Back surface field, BSF)，再使用本實驗室開發之網印塗佈高分子漿料搭配化學濕式蝕刻之圖案製程技術，相較於雷射製程會造成基板表面損傷，本實驗重點為開發濕式共蝕刻(Co-etch back)技術，利用濕式回蝕刻同時製作出選擇性射極(Selective Emitter, SE)及選擇性背表面電場(Selective Back surface field,SBSF) 之結構，能良好調控片電阻(Ω/square)變化，並且不破壞矽基板表面織構化結構，同時探討富含氫氟酸之HNA蝕刻溶液對於射極層(p+ layer)及背表面電場(n+ layer)片電阻變化之機制，能同時將射極層片電阻40 Ω/□及背表面電場片電阻25 Ω/□同時蝕刻至100 Ω/□，最後歸納出富含氫氟酸之蝕刻液的配比趨勢變化，可應用於不同之片電阻參數條件，調配出不同之最佳蝕課液比例。
本研究利用PC2D模擬不同選擇性結構之雙面太陽能電池，比較選擇性結構用於正背面之間差異，結果為雙面選擇性結構轉換效率提升0.9%，改善開路電壓24 mV及提升短路電流0.6 mA/cm2。在實驗結果中，我們發現經由共蝕刻製程相較於傳統回蝕刻製程節省了一個環節，利用共蝕刻製程製作太陽能電池，改善了射極層表面複合及背表面電場內部複合，符合模擬選擇性結構之趨勢，轉換效率提升0.67%，開路電壓提升9.24 mV，短路電流提升0.61 mA/cm2。

In this experiment, we investigate the dehydration mechanism of boric acid and use TGA analysis to improve the pre-bake heating method to increase the usage rate of boron source. Then, using the screen printing polymer paste as the etching mask developed by our laboratory. The focus point of this experiment is to develop wet co-etching technology, which uses wet etch back to simultaneously fabricate selective emitter(SE) and selective back surface field (SBSF) structures. This technology can well control the sheet resistance (Ω/square) and maintain the texture structure.
We investigate the mechanism of the resistance change of the hydrogen fluoride-rich HNA etching solution for the emitter layer (p+ layer) and the back surface field (n+ layer). In our experimental parameter, the sheet resistance of selective emitter is 40 Ω/□ and sheet resistance of the back surface field is 25 Ω/□ , which can be co-etched back to 100 Ω/□ by the optimal recipe. Finally, the ratio change of the hydrofluoric acid-rich etching solution can be applied to different sheet resistances.
This research uses PC2D to simulate bifacial solar cells with different selective structures. The selective structure is used for the difference between the front and the back. As a result, the bifacial selective structure can improve the efficiency 0.9%, the open circuit voltage 24 mV, the short-circuit current 0.6 mA/cm2.In the result, the selective bifacial solar cell is produced by the co-etching technology, which improves the surface recombination of the emitter layer and the internal recombination of the back surface electric field. Compare to the reference cell, the selective bifacial solar cell improves the efficiency 0.67%, the open circuit voltage 9.24 mV, the short-circuit current 0.61 mA/cm2.

[1] Research Cell Efficiency Records.Available at: https//www.nrel.gov/pv/.
[2] International Technology Roadmap for Photovoltaic Results 2017 – Presentation.
[3] M. Acciarri, S. Binetti, A. Le Donne, S. Marchionna, M. Vimercati, J. Libal,R. Kopecek, K. Wambach, Prog. Photovolt. Res. Appl. 15 375–386 (2007).
[4] Karsten Bothe, Ron Sinton, Jan Schmidt, Prog. Photo.: Res. Appl. 13 287–296 (2005).
[5] S. O. Kasap, Optoelectronics and Photonics Principles and Practices, Prentice -Hall, ed. 1.0, (2001).
[6] A. B. Sproul, M. A. Green, and A. W. Stephens, J. Appl. Phys., 72, 4161-4171 (1992).
[7] http://pveducation.org/pvcdrom/solar-cell-operation/quantum-efficiency
[8] S. Pizzini, Solar Energy Materials & Solar Cells, 94, 1528-1533 (2010).
[9] Daniel Macdonald, IEEE, 2, 0-7803-7471-1(2002).
[10] M. Kerr and A. Cuevas, Journal of Applied Physics, 91, 2473-2481 (2002).
[11] Muramatsu, S., et al., Solar Energy Materials and Solar Cells., 65, 599-606 (2001).
[12] Lee, Y., et al., Nanoscale Research Letters, 7, 1-6 (2012).
[13] Dauwe, S., et al., Progress in photovoltaics, 10, 271-278 (2002).
[14] Salemi, S., et al., Journal of Applied Physics (2013).
[15] Chang, L.S., P.L. Gendler, and J.H. Jou, Journal of Materials Science, 26, 1882-1890 (1999).
[16] Jang, J.H. and K.S. Lim, Japanese journal of applied physics part 1-regular papers short notes & review papers, 36, 6230-6236 ,(1997).
[17] Sepeai S. et al., International Journal of Photoenergy, 10, 1155-1162(2012).
[18] J Del Alamo, J Van Meerbergen, F d'Hoore, J Nijs, Solid-State Electronics, 24, 533-538 (1980).
[19] Michael P. Godlewski, Cosmo R. Baraona, Henry W, 10th Photovoltaic Specialists' Conf., IEEE, 29, 131-150 (1990).
[20] Arnab Das, PhD dissertation, Atlanta, Georgia, Georgia: Institute of Technology, School of Electrical and Computer Engineering, (2012)
[21] A. G. Aberle, University of New South Wales, Sydney NSW 2052 (1999).
[22] J. P. Colinge and C. A. Colinge, Physics of semiconductor devices, Kluwer academic publishers (2005).
[23] S. M. Sze, and K. K. Ng, Physics of semiconductor devices, John Wiley & Sons, Inc., Hoboken, NJ, USA. (2006).
[24] S.J. Choi, et al., Renewable Energy, 54, 96-100 (2013).
[25] A. B. Sproul, M. A. Green, and A. W. Stephens, J. Appl. Phys., 72, 4161-4171 (1992).
[26] M. S. Tyagi and R. V. Overstraeten, Solid-St. Electron., 26, 577-597 (1983).
[27] M. J. Kerr and A. Cuevas, J. Appl. Phys., 91, 97-104 (2002).
[28] W. Shockley and W. Read, Phys. Rev., 87, 835-842 (1952).
[29] I. Martín, M. Vetter, M. Garín, A. Orpella, C. Voz, J. Puigdollers, and R. Alcubilla , Journal of Applied Physics, 98, 114912-114921 (2005).
[30] M. Kerr and A. Cuevas, Journal of Applied Physics, 91, 2473-2481 (2002).
[31] S. Dauwe, harderberg ,2004.
[32] H. Park et al, International Journal of Photoenergy, 794867 (2012).
[33] G. Singh, V. Amit, R. Jeyakumar, The Royal Society of Chemistry, 4, 4225–4229 (2014).
[34] A. Das, PhD dissertation, Atlanta, Georgia, Georgia: Institute of Technology, School of Electrical and Computer Engineering (2012).
[35] J. Peter , IEEE Transactions on electron devices, 53, 3 (2006).
[36] H. Park et al, International Journal of Photoenergy, 794867 (2012).
[37] K.S. Ryu, PhD dissertation ,Georgia Institute of Technology (2015).
[38] V. D. Mihailetchi, Proc. 25th Eur. Photovoltaic Sci. Eng. Conf., 1446–1448 (2010).
[39] G. Singh, The Royal Society of Chemistry, 4, 4225–4229 (2014).
[40] J. LIBAL. et al., Proceedings of the 22th European Photovoltaic Solar Energy Conference, 1382-1386 (2007).
[41] J. Y. Lee and S. W. Glunz, Proc. 19th EU-PVSEC, 998-1001 (2004).
[42] G. Bueno, Proc., 20th EU-PVSEC, 1458-1461 (2005).
[43] A. Das, PhD dissertation, Atlanta, Georgia, Georgia: Institute of Technology, School of Electrical and Computer Engineering (2012).
[44] http://www.pv-tech.org/solar-media-store-shutdown
[45] Heinrich, G. et al. Energy Procedia 8, 592 (2011).
[46]Röder, T. C., Eisele, S. J., Grabitz, P., Wagner, C., Kulushich, G., Köhler, J. R., & Werner, J. H., in Photovoltaics: Research and Applications 18(7), 505 (2010).
[47] Sipe, J. E., Young, J. F., Preston, J. S. &VanDriel, H. M. Phys. Rev. B 27, 1141 (1983).
[48] Brand, A. A., Knorz, A., Zeidler, R., Nekarda, J.-F. & Preu, R. SPIE. 8473, 84730D ,(2012).
[49] Kim, M., Kim, D., Kim, D. &Kang, Y. Sol. Energy 109, 105 (2014).
[50] H. Antoniadis , F. Jiang, W. Shan, Y. L. in Proceedings of the 35th IEEE Photovoltaic Specialists Conference 1193 (2010).
[51] Basu, P. K., Cunnusamy, J., Sarangi, D. &Boreland, M. B. Renew. Energy 66, 69 (2014).
[52] D. Rudolph, K. Peter, A. Meijer, O. Doll, I. K. in the 26th European Photovoltaic Solar Energy Conference and Exhibition 1349 (2011).
[53] H. Haverkamp, A. Dastgheib-Shirazi, B. Raabe, F. Book, G. H. in Photovoltaic Specialists Conference (2008).
[54] F. Book, S. Braun, A. Herguth, A. Dastgheib-Shirazi, B. Raabe, G. H. in Photovoltaic Specialists Conference 1309 (2010).
[55] H. Robbins and B. Schwartz, J. Electrochem. Soc, 108, 365–372 (1961)
[56] E. A. Starostina, V. V. Starkov, A. F. Vyatkin, Russian Microelectronics, Vol. 31, No. 2, pp. 88–96 (2002)
[57] R. Pankajavalli, S. Anthonysamy, K. Ananthasivan, P.R. Vasudeva Rao, Journal of Nuclear Materials, 362 ,128–131 (2007)
[58] A. OHNO, M. KITAMURA, T. YAMANAKA, Japan Nuclear Cycle Development Institute 4-33 Muramatsu, Tokai-mura, Naka-gun, Ibaraki, 319-1194 , Japan
[59]S.M. Myers*, G.A. Petersen, T.J. Headley, J.R. Michael, T.L. Aselage, C.H. Seager. Nuclear Instruments and Methods in Physics Research B 127 128 , 291-296( 1997)
[60] V. Vähänissi*, A. Haarahiltunen, H. Talvitie, M. Yli-Koski, J. Lindroos, and H. Savin, Phys. Status Solidi RRL 4, No. 5–6, 136–138 (2010)
[61] T. Unagami, Nippon Telegraph and Telephone Public Corporation, Musashino Electrical Communication Laboratory, Musashino-shi, Tokyo, 180, Japan (1980)