Journal of the Microelectronics and Packaging Society (마이크로전자및패키징학회지)

The Korean Microelectronics and Packaging Society (한국마이크로전자및패키징학회)
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A Study of Moth-eye Nano Structure Embedded Optical Film with Mitigated Output Power Loss in PERC Photovoltaic Modules

PERC 태양전지 모듈의 출력저하 방지를 위한 모스아이(Moth-eye) 광학필름 연구

  • Oh, Kyoung-suk (New & Renewable Energy Research Center, Korea Electronics Technology Institute) ;
  • Park, Jiwon (New & Renewable Energy Research Center, Korea Electronics Technology Institute) ;
  • Choi, Jin-Young (Nanomecca) ;
  • Chan, Sung-il (New & Renewable Energy Research Center, Korea Electronics Technology Institute)
  • Received : 2020.11.12
  • Accepted : 2020.12.30
  • Published : 2020.12.30
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Abstract

The PERC photovoltaic (PV) modules installed in PV power plant are still reports potential-induced degradation (PID) degradation due to high voltage potential differences. This is because Na+ ions in the cover glass of PV modules go through the encapsulant (EVA) and transferred to the surface of solar cells. As positive charges are accumulated at the ARC (SiOx/SiNx) interface where many defects are distributed, shunt-resistance (Rsh) is reduced. As a result, the leakage current is increased, and decrease in solar cell's power output. In this study, to prevent of this phenomenon, a Moth-eye nanostructure was deposited on the rear surface of an optical film using Nano-Imprint Lithography method, and a solar mini-module was constructed by inserting it between the cover glass and the EVA. To analyze the PID phenomenon, a cell-level PID acceleration test based on IEC 62804-1 standard was conducted. Also analyzed power output (Pmax), efficiency, and shunt resistance through Light I-V and Dark I-V. As a result, conventional solar cells were decreased by 6.3% from the initial efficiency of 19.76%, but the improved solar cells with the Moth-eye nanostructured optical film only decreased 0.6%, thereby preventing the PID phenomenon. As of Moth-eye nanostructured optical film, the transmittance was improved by 4%, and the solar module output was improved by 2.5%.

태양광 발전소에 설치된PERC 태양광 모듈 스트링-어레이는 고전압의 전위차로 인해 여전히 potential-induced degradation(PID) 열화 현상이 여전히 보고되고 있다. 이는 태양전지 모듈 커버글라스의 Na+ 이온이 태양전지 봉지재(EVA)를 투과하여 셀 표면으로 전이되고 결함이 많이 분포되어 있는 ARC(SiOx/SiNx) 계면에 양전하가 축적됨으로써 shunt-Resistance(Rsh)가 감소되고 누설전류량이 증가되어 태양전지 출력이 저하되는 현상이다. 본 연구에서는 이를 방지하기 위해 나노임프린트 리소그래피(nano-imprint lithography, NIL) 방식을 이용하여 모스아이(Moth-eye) 나노 구조를 광학 필름 후면에 증착 하였고, 이를 커버글라스와 EVA 사이에 삽입하여 태양광 미니 모듈을 구성하였다. PID 열화 현상을 확인하기 위해 IEC 62804-1 규격에 기반한 셀 단위 PID 열화가속시험을 진행하였고, Light I-V, Dark I-V 분석을 통해 출력(Pmax), 효율(Efficiency), 병렬 저항(shunt resistance)을 확인하였다. 그 결과 기존의 태양전지는 초기 효율 19.76%에서 6.3% 감소하였으나 모스아이 나노 구조 광학 필름(Moth-eye film)이 적용된 태양전지는 0.6% 만 감소하여 PID 열화 현상이 방지되는 것을 확인하였고, 모스아이 나노구조를 통해 투과도가 4% 향상되어 미니 모듈 출력이 2.5% 향상되었다.

Keywords

References

  1. NREL Best Research-Cell Efficiencies, NREL. (2020) from http://www.nrel.gov/pv/cell-efficiency.html
  2. W. Oh, S. Bae, D. Kim, and N. Park, "Initial detection of potential-induced degradation using dark I-V characteristics of crystalline silicon photovoltaic modules in the outdoors", Microelectronics Reliability, 88, 998 (2018). https://doi.org/10.1016/j.microrel.2018.06.093
  3. W. Luo, P. Hacke, S. M. Hsian, Y. Wang, A. G. Aberle, S. Ramakrishna, and Y. S. Khoo, "Investigation of the impact of illumination on the polarization-type potential-induced degradation of crystalline silicon photovoltaic modules", IEEE Journal of Photovoltaics, 8(5), 1168 (2018). https://doi.org/10.1109/jphotov.2018.2843791
  4. B. J. Bae, S. H. Hong, E. J. Hong, H. Lee, and G. Y. Jung, "Fabrication of moth-eye structure on glass by ultraviolet imprinting process with polymer template", Japanese Journal of Applied Physics, 48(1R), 010207 (2009). https://doi.org/10.1143/JJAP.48.010207
  5. K. S. Han, J. H. Shin, and H. Lee, "Enhanced transmittance of glass plates for solar cells using nano-imprint lithography", Solar Energy Materials and Solar Cells, 94(3), 583 (2010). https://doi.org/10.1016/j.solmat.2009.12.001
  6. J. W. Leem, X. Y. Guan, M. Choi, and J. S. Yu, "Broadband and omnidirectional highly-transparent coverglasses coated with biomimetic moth-eye nanopatterned polymer films for solar photovoltaic system applications", Solar Energy Materials and Solar Cells, 134, 45 (2015). https://doi.org/10.1016/j.solmat.2014.11.025
  7. K. S. Han, H. Lee, D. Kim, and H. Lee, "Fabrication of antireflection structure on protective layer of solar cells by hotembossing method", Solar Energy Materials and Solar Cells, 93(8), 1214 (2009). https://doi.org/10.1016/j.solmat.2009.01.002
  8. S. Ju, J. Y. Choi, D. Chae, H. Lim, H. Kang, and H. Lee, "Fabrication of high-transmittance and low-reflectance meterscale moth-eye film via roll-to-roll printing", Nanotechnology, 31(50), 505301 (2020). https://doi.org/10.1088/1361-6528/aba7e4
  9. K. S. Oh, S. H. Bae, K. J. Lee, D. H. Kim, and S. I. Chan, "Mitigation of potential-induced degradation (PID) based on anti-reflection coating (ARC) structures of PERC solar cells", Microelectronics Reliability, 100, 113462 (2019).
  10. K. S. Oh, M. Byun, M. Kim, Y. D. Kim, K. Kim, D. Huh, and H. Lee, "Hexagonal array micro-convex patterned substrate for improving diffused transmittance in perovskite solar cells", Thin Solid Films, 660, 682 (2018). https://doi.org/10.1016/j.tsf.2018.04.017
  11. P. B. Clapham and M. C. Hutley, "Reduction of lens reflexion by the "Moth Eye" principle", Nature, 244(5414), 281 (1973). https://doi.org/10.1038/244281a0
  12. E. J. Hong, K. J. Byeon, H. Park, J. Hwang, H. Lee, K. Choi, and G. Y. Jung, "Fabrication of moth-eye structure on p-GaN layer of GaN-based LEDs for improvement of light extraction", Materials Science and Engineering: B, 163(3), 170 (2009). https://doi.org/10.1016/j.mseb.2009.05.018
  13. G. K. Chang, Y. K. Lim, and J. C. Jeong, "Textured Surface Epitaxial Base Silicon Solar cell", J. Microelectron. Packag. Soc., 10(2), 33 (2003).
  14. K. R. McIntosh and C. B. Honsberg, "The Influence of Edge Recombination on a Solar Cell's IV Curve", Proc. 16th European Photovoltaic Solar Energy Conference (EU PVSEC), Australia, 2052 (2000).
  15. E. L. Meyer, "Extraction of Saturation Current and Ideality Factor from Measuring Voc and Isc of Photovoltaic Modules", International Journal of Photoenergy, 2017, 8479487 (2017). https://doi.org/10.1155/2017/8479487
  16. I. Martil and G. Diaz, "Determination of the dark and illuminated characteristic parameters of a solar cell from I-V characteristics", Eur. J. Phys., 13, 193 (1992). https://doi.org/10.1088/0143-0807/13/4/009
  17. J. Zhao, A. Wang, X. Dai, M. A. Green, and S. R. Wenham, "Improvements in Silicon Solar Cell Performance", Proc. 22nd Photovoltaic Specialists Conference (PVSC), Las Vegas, NV, USA, 399, IEEE (1991).
  18. V. Naumann, D. Lausch, A. Hahnel, J. Bauer, O. Breitenstein, A. Graff, and C. Hagendorf, "Explanation of potential-induced degradation of the shunting type by Na decoration of stacking faults in Si solar cells", Solar Energy Materials and Solar Cells, 120, 383 (2014). https://doi.org/10.1016/j.solmat.2013.06.015
  19. D. W. Jung, K. S. Oh, E. Jang, S. I. Chan, and S. W. Ryu, "Thickness Effect of SiO x Layer Inserted between AntiReflection Coating and pn Junction on Potential-Induced Degradation (PID) of PERC Solar Cells", J. Microelectron. Packag. Soc., 26(3), 75 (2019).
  20. S. Yamaguchi and K. Ohdaira, "Degradation behavior of crystalline silicon solar cells in a cell-level potential-induced degradation test", Solar Energy, 155, 739 (2017). https://doi.org/10.1016/j.solener.2017.07.009
  21. H. Tanaka and K. S. Kim, "Reliability Evaluation for Photovoltaic Modules", J. Microelectron. Packag. Soc., 19(2), 1 (2012). https://doi.org/10.6117/kmeps.2012.19.2.001