近些年來鑽石切割技術已經成為矽晶太陽能電池之主流切割技術，過往的砂漿切割技術幾乎在太陽能電池之裸片切割市場上被取代。而針對鑽石線切割晶片因為晶片經過切割後之鑽石切割痕與過往砂漿切割之痕跡有差異，因此進行製絨會有所差異，必須調整過往之製程以達到降低反射率之目的。
本實驗利用p型單晶矽太陽能電池基板來進行實驗。本實驗將會對基板進行表面製絨之實驗，首先會以銅做為金屬催化劑之酸蝕刻液作進行表面製絨，製作出倒金字塔之結構。實驗之第一步蝕刻將會固定溫度及金屬濃度，並調整氫氟酸及雙氧水之濃度作為改變之參數，而本論文採取用與多數文獻相比較低氫氟酸濃度來進行實驗。而針對第一步之結果必須進行鹼溶液浸泡的步驟，以修飾表面形貌得到較佳之倒金字塔結構，最後會藉由拍攝SEM去分析其形貌結構，並藉由反射率之量測，觀察其結構與反射率之間的關係，本實驗也將與商用的正金字塔形貌結構片作為反射率量測之比較片並且將量測晶片之厚度得第一步蝕刻濃度與晶片蝕刻損耗之間的關係。

In recent years, diamond wire cutting technology has become the mainstream cutting technique for silicon solar cell wafers, replacing the traditional slurry cutting technique in the solar cell wafer cutting market. However, for diamond-wire-sawn wafers, the diamond-cutting marks left on the wafers after cutting are different from the marks left by the previous slurry cutting technique. As a result, the subsequent texturing process will differ, requiring adjustments to the existing processes to achieve the goal of reducing reflectance.
In this study, we use p-type monocrystalline silicon solar cell substrates for investigation. The experiment will focus on surface texturing of the substrates. Initially, a copper-based acid etchant, serving as a metal catalyst, is used for surface texturing to create a inverted-pyramid-like structure. In the first step of the experiment, etching will be conducted at a fixed temperature and metal concentration, with adjustments made for the concentrations of hydrofluoric acid and hydrogen peroxide as variable parameters. This study adopts a lower hydrofluoric acid concentration compared with most literature. Following the results of the first step, an alkaline solution soaking step is necessary to modify the surface morphology and achieve an improved inverted pyramid structure. Subsequently, the morphology structure will be analyzed through scanning electron microscope (SEM) imaging, and the relationship between the structure and reflectance will be observed through reflectance measurements. This experiment will also compare the reflectance measurements with commercially available wafers featuring a regular pyramid morphology structure. Additionally, the relationship between the first step etching concentration and wafer etching loss will be explored by measuring the wafer thickness.

目錄
摘要 i
Abstract ii
致謝 iii
目錄 iv
圖目錄 vi
表目錄 xi
第一章、序論 1
1.1 太陽能電池現況 1
1.2 研究目的以及動機 2
1.3 文獻回顧 3
1.4 論文架構 5
第二章、太陽能電池基本原理 6
2.1半導體元件物理特性 6
2.2 半導體載子產生與復合 7
2.3太陽能電池原理 8
2.3.1 P-N接面(P-N junction) 8
2.3.2 太陽光譜(solar spectrum) 9
2.3.3 太陽能電池之運作 11
2.3.4 太陽能電池等效電路 12
2.3.5 太陽能電池參數 13
2.3.6電池效率損失因素及改善方案 15
2.4 太陽能電池蝕刻製程 16
2.4.1 矽基太陽能電池基板之切割方式 16
2.4.2 鹼蝕刻製程 17
2.4.3 酸蝕刻製程 18
2.4.4 金屬輔助化學蝕刻 19
2.5 倒金字塔結構 22
第三章、研究方法與製程步驟 23
3.1 實驗架構 23
3.2 實驗步驟 25
3.3.1 RCA Cleaning介紹: 25
3.3.2 MACE Etch Process & Structure modify: 27
第四章、實驗數據分析 30
4. 1 一步驟銅蝕刻濃度調整: 30
4.2 鹼溶液的表面結構修飾調整 35
4.3 反射率量測 50
4.4 濃度對蝕刻的厚度之關係 60
4.5 不同參數鹼浸泡之情形 63
第五章、結論及未來展望 65
參考文獻 67

[1] J. Zhang, X. Zhou, L. Zhou, Y. Kuang, and Y. Liu, “Surface modification of diamond wire sawn multi-crystalline silicon wafers by grinding pre-treatment for wet acid texturization,” Materials Science in Semiconductor Processing, vol. 117, pp.105191,2020.

[2] Y. W. Peng and H. C. Chang, “An overview and perspectives of back-contacted silicon solar cells,” [Online]. Available: https://www.materialsnet.com.tw

[3] R. Watanabe, S. Abe, S. Haruyama, T. Suzuki, M. Onuma, and Y. Saito, “Evaluation of a new acid solution for texturization of multicrystalline silicon solar cells,” International Journal of Photoenergy, vol. 2013, pp.951303, 2013.

[4] T.-C. Wang, H.-Y. Lee, C.-T. Lee, Y.-C. Cheng, and H.-W. Chen, “Investigated performance improvement of the micro-pressure sandblast-treated multi-crystalline Si wafer sliced using diamond wire sawing,” Solar Energy, vol. 161, pp. 220-225, 2018.

[5] Y. Jung, K. Min, S. Bae, M. Sim, Y. Kang, H. Lee, and D. Kim, “Pre-texturing thermal treatment for saw-damage-removal-free wet texturing of monocrystalline silicon wafers,” Energies, vol. 13, no. 24, pp. 6610, 2020.

[6] A. W. Smith and A. Rohatgi, “Ray tracing analysis of the inverted pyramid texturing geometry for high efficiency silicon solar cells,” Solar Energy Materials and Solar Cells, vol. 29, no. 1, pp. 37–49. 1993.

[7] A. Mavrokefalos, S. E. Han, S. Yerci, M. S. Branham, and G. Chen, “Efficient light trapping in inverted nanopyramid thin crystalline silicon membranes for solar cell applications,” Nano Letters, vol. 12, no. 6, pp. 2792-2796, 2012.

[8] X. Li and P. Bohn, “Metal-assisted chemical etching in HF/H2O2 produces porous silicon,” Appl. Phys. Lett., vol. 77, pp. 2000-2572, 2000.


[9] K. Peng, Y. Xu, Y. Wu, Y. Yan, S.-T. Lee, and J. Zhu, “Aligned single-crystalline Si nanowire arrays for photovoltaic applications,” small, vol. 1, no. 11, pp. 1062 – 1067, 2005.

[10] Z. G. Huang, K. Gao, X. G. Wang, C. Xu, X. M. Song, L. X. Shi, Y. Zhang, B. Hoex, and W. Z. Shen, “Large-area MACE Si nano-inverted-pyramids for PERC solar cell application,” Solar Energy, vol. 188, pp. 300–304, 2019.

[11] Y.-T. Lu and A. R. Barron, “Anti-reflection layers fabricated by a one-step copper-assisted chemical etching with inverted pyramidal structures intermediate between texturing and nanopore-type black silicon,” Journal of Materials Chemistry A, vol. 28, no. 30, pp. 12043–12052, 2014.

[12] Y. Wang, L. Yang, Y. Liu, Z. Mei, W. Chen, J. Li, H. Liang, A. Kuznetsov, and D. Xiaolong, “Maskless inverted pyramid texturization of silicon,” Scientific Reports, vol. 5, no. 1, pp. 10843, 2015.

[13] S.-D. Wang, S.-Y. Chen, S.-P. Hsu, P.-Q. Shi, and C.-G. Chen, “Effects of H2O2, Cu(NO3)2 and HF temperatures on surface texturization of diamond-wire-sawn multicrystalline silicon wafer,” Solar Energy Materials and Solar Cells, vol. 212, pp. 110583, 2020.

[14] Y. Zhao, Y. Liu, W. Chen, J. Wu, Q. Chen, H. Tang, Y. Wang, and X. Du,
“Regulation of surface texturization through copper-assisted chemical etching for silicon solar cells,” Solar Energy, vol. 201, pp. 461–468, 2020.

[15] D.-K. Seo and R. Hoffmann, “Direct and indirect band gap types in one-dimensional conjugated or stacked organic materials,” Theoretical Chemistry Accounts, vol. 102, no. 1, pp. 23-32, 1999.

[16] P.-M. Jong. “Carrier Recombination and Generation.” [Online]. Available:
https://www.iue.tuwien.ac.at/phd/park/node31.html

[17] W. David. “Introduction to PN Junction.” [Online]. Available:
https://www.theengineeringprojects.com/2018/05/introduction-to-pn-junction.html

[18] “MKS New report.” [Online]. Available:
https://www.newport.com/t/introduction-to-solar-radiation

[19] A. Funde and A. Shah, “Solar Spectra,” Solar Cells and Modules, pp.17-32, 2020

[20] B. Minnaert and P. Veelaert, “A proposal for typical artificial light sources for the characterization of indoor photovoltaic applications,” Energies, vol. 7, no. 3, pp.1500-1516, 2014.

[21] A. Kavaz, S. Hodžić, T. Hubana, S. Ćurevac, N. Đozić, H. Merzić, H. Tanković, K. Dervišević, E. Alihodžić, E. Sikira, D. Rahić, N. Kavazović, F. Tanković, and B. Šestan, “Solar Tree Project.” [Online]. Available:
https://www.researchgate.net/publication/322628682_Solar_Tree_Project

[22] Z. Sun, J. Lu, H. Zhang, G. Li, and Z. Xie, “Performance test of solar cell under laser energy transmission and signal transmission,” Infrared and Laser Engineering, vol. 51, pp. 20210888, 2022.

[23] M. El-Ahmar, A.-H. Ahmed, and A. Hemeida, “Mathematical modeling of Photovoltaic module and evalute the effect of varoius paramenters on its performance”, Eighteenth International Middle East Power Systems Conference 2016, vol. 2016, pp. 741-746, 2016.

[24] D. Zhang, S. Jiang, K. Tao, R. Jia, H. Ge, X. Li B. Wang, M. Li, Z. Ji, Z. Gao, and Z. Jin, “Fabrication of inverted pyramid structure for high-efficiency silicon solar cells using metal assisted chemical etching method with CuSO4 etchant,” Solar Energy Materials and Solar Cells, vol. 230, pp.111200, 2021.



[25] “Solar silicon wafers produced by diamond wire sawn (DWS).”
[Online]. Available:
https://www.dsneg.com/info/solar-silicon-wafers-produced-by-diamond-wire-49753748.html

[26] U. Gangopadhyay, S. K. Dhungel, A. K. Mondal, H. Saha, and J. Yi, “Novel low-cost approach for removal of surface contamination before texturization of commercial monocrystalline silicon solar cells,” Solar Energy Materials and Solar Cells, vol. 91, no. 12, pp.1147–1151, 2007.

[27] H. Seidel, L. Csepregi, A. Heuberger, and H. Baumgärtel, ” Anisotropic etching of crystalline silicon in alkaline solutions: I . orientation dependence and behavior of passivation layers,” Journal of The Electrochemical Society, vol. 137, no. 11, pp. 3612, 1990.

[28] R. B. Darling, “EE-527: Micro Fabrication Wet Etching.” [Online]. Available:
https://docplayer.net/21086454-Ee-527-microfabrication.html

[29] A. A. Hamzah, N. Abd Aziz, B. Yeop Majlis, J. Yunas, C. F. Dee, and B. Bais, “Optimization of HNA etching parameters to produce high aspect ratio solid silicon microneedles,” Journal of Micromechanics and Microengineering, vol. 22, no. 9, pp. 095017, 2012.

[31] Z. Huang, N. Geyer, P. Werner, J. de Boor, and U. Gösele, “Metal-Assisted Chemical Etching of Silicon: A Review,” Advanced Materials, vol. 23, no. 2, pp. 285–308, 2011.

[32] X. Wu, Y. Tan, H. Wu, J. Li, M. Cai, and P. Li, “Structural modification of diamond-wire-cut multicrystalline Si by Cu-catalyzed chemical etching for surface structuring,” Thin Solid Films, vol. 740, pp. 139199, 2022.




[33] K. Q. Peng, J. J. Hu, Y. J. Yan, Y. Wu, H. Fang, Y. Xu, et al., “Fabrication of single-crystalline silicon nanowires by scratching a silicon surface with catalytic metal particles,” Advanced Functional Materials, vol. 16, no. 3, pp.387–394, 2006.

[34] Y. Wang, Y. Liu, L. Yang, W. Chen, X. Du, and A. Kuznetsov, “Micro-structured inverted pyramid texturization of Si inspired by self-assembled Cu nanoparticles,” Nanoscale, vol. 9, no. 2, pp. 907–914,2017.

[35] S. C. Baker-Finch and K. R. McIntosh, “Reflection of normally incident light from silicon solar cells with pyramidal texture,” Progress in Photovoltaics: Research and Applications, vol. 19, no. 4, pp. 406–416, 2011.

[36] L. Yang, Y. Liu, Y. Wang, W. Chen, Q. Chen, J. Wu, et al.,”18.87%-efficient inverted pyramid structured silicon solar cell by one-step Cu-assisted texturization technique,” Solar Energy Materials and Solar Cells, vol. 166, pp. 121-126, 2017.

[37] A. Kumar and S. N. Melkote, “Diamond wire sawing of solar silicon wafers: A sustainable manufacturing alternative to loose abrasive slurry sawing,” Procedia Manufacturing, vol. 21, pp. 549–566, 2018.

[38] R. Barrio Martín, N. Gonzalez, J. Cárabe, and J. J. Gandía, “Texturization processes of monocrystalline silicon with Na2CO3/NaHCO3 solutions for solar cells,” Materials Science in Semiconductor Processing, vol. 16, pp. 1-9, 2014.