Current Photovoltaic Research

Korea Photovoltaic Society (한국태양광발전학회)
권호 표지
DOI QR코드

DOI QR Code

Optimization of the Phosphorus Doped BSF Doping Profile and Formation Method for N-type Bifacial Solar Cells

  • Cui, Jian (College of Information and Communication Engineering, Sungkyunkwan University) ;
  • Ahn, Shihyun (College of Information and Communication Engineering, Sungkyunkwan University) ;
  • Balaji, Nagarajan (Department of Energy Science, Sungkyunkwan University) ;
  • Park, Cheolmin (Department of Energy Science, Sungkyunkwan University) ;
  • Yi, Junsin (College of Information and Communication Engineering, Sungkyunkwan University)
  • Received : 2015.12.24
  • Accepted : 2016.01.07
  • Published : 2016.06.30
Download PDF
⟨ Previous Next ⟩

Abstract

n-type PERT (passivated emitter, rear totally diffused) bifacial solar cells with boron and phosphorus diffusion as p+ emitter and n+ BSF (back surface field) have attracted significant research interest recently. In this work, the influences of wafer thickness, bulk lifetime, emitter, BSF on the photovoltaic characteristics of solar cells are discussed. The performance of the solar cell is determined by using one-dimensional solar cell simulation software PC1D. The simulation results show that the key role of the BSF is to decrease the surface doping concentration reducing the recombination and thus, increasing the cell efficiency. A lightly phosphorus doped BSF (LD BSF) was experimentally optimized to get low surface dopant concentration for n type bifacial solar cells. Pre-oxidation combined with a multi-plateau drive-in, using limited source diffusion was carried out before pre-deposition. It could reduce the surface dopant concentration with minimal impact on the sheet resistance.

Keywords

References

  1. D. M. Chapin, C. S. Fuller, and G. L. Pearson. A New Silicon p-n Junction Photocell for Converting Solar Radiation into Electrical Power. Journal of Applied Physics, 25 (5):676, 1954. https://doi.org/10.1063/1.1721711
  2. J. E. Cotter, et al. "P-type versus n-type Silicon Wafers: Prospects for High-Efficiency Commercial Silicon Solar Cells." IEEE Transactions on Electron Devices, 53(8):1893-1901, 2006. https://doi.org/10.1109/TED.2006.878026
  3. S. W. Glunz, S. Rein, J. Y. Lee, and W. Warta. "Minority carrier lifetime degradation in boron-doped Czochralski silicon." Journal of Applied Physics, 90(5):2397, 2001. https://doi.org/10.1063/1.1389076
  4. J. Schmidt, et al. "N-type silicon - The better material choice for industrial high efficiency solar cells." In Proceedings of the 22th European Photovoltaic Solar Energy Conference and Exhibition, 2007.
  5. J. Schmidt and K. Bothe, "Structure and transformation of the metastable boron- and oxygen-related defect center in crystalline silicon," Physical Review B, vol. 69, no. 2, Article ID 024107, pp. 241071-241078, 2004.
  6. S. W. Glunz, S. Rein, J. Y. Lee, and W. Warta, "Minority carrier lifetime degradation in boron-doped Czochralski silicon," Journal of Applied Physics, vol. 90, no. 5, pp. 2397-2404, 2001. https://doi.org/10.1063/1.1389076
  7. J. Schmidt, A. G. Aberle, and R. Hezel, "Investigation of carrier lifetime instabilities in Cz-grown silicon," in Proceedings of the 1997 IEEE 26th Photovoltaic Specialists Conference, pp. 13-18, October 1997.
  8. D. Macdonald and L. J. Geerligs, "Recombination activity of interstitial iron and other transition metal point defects in p and n-type crystalline silicon," Applied Physics Letters, vol. 85, no. 18, pp. 4061-4063, 2004. https://doi.org/10.1063/1.1812833
  9. Fabian Kiefer, et al, "Influence of the boron emitter profile on VOC and JSC losses in fully ion implanted n-type PERT solar cells." Phys. Status Solidi A 212, No. 2, 291-297 (2015). https://doi.org/10.1002/pssa.201431118
  10. Vinodh Shanmugam et al., "Electrical and Microstructural Analysis of Contact Formation on Lightly Doped Phosphorus Emitters sing Thick-Film Ag Screen Printing Pastes," IEEE JOURNAL OF PHOTOVOLTAICS, VOL. 4, NO. 1, 2014.
  11. J. Schmidt, J. Bothe, R. Bock, C. Schmiga, R. Krain, and R. Brendel. "N-type silicon - The better material choice for industrial high efficiency solar cells." In Proceedings of the 22th European Photovoltaic Solar Energy Conference and Exhibition, 2007.
  12. S. P. Phang and D. Macdonald. "Direct comparison of boron, phosphorus, and aluminum gettering of iron in crystalline silicon." Journal of Applied Physics, 109(7):073521, 2011. https://doi.org/10.1063/1.3569890
  13. M. Rudiger, C. Schmiga, M. Rauer, M. Hermle, and S. W. Glunz. "Efficiency Potential of n-Type Silicon Solar Cells with Aluminum-Doped Rear p+ Emitter." IEEE Transactions on Electron Devices, 59(5):1295-1303, May 2012. https://doi.org/10.1109/TED.2012.2187655
  14. F. Book, T. Wiedenmann, G. Schubert, H. Plagwitz, and G. Hahn. "Influence of the Front Surface Passivation Quality on Large Area n-Type Silicon Solar Cells with Al-Alloyed Rear Emitter." Energy Procedia, 8:487-492, 2011.
  15. J. Zhao, A. Wang, and M. A. Green. "24.5% Efficiency silicon PERT cells on MCZ substrates and 24.7% efficiency PERL cells on FZ substrates." Progress in Photovoltaics: Research and Applications, 7(6):471-474, November 1999. https://doi.org/10.1002/(SICI)1099-159X(199911/12)7:6<471::AID-PIP298>3.0.CO;2-7
  16. J.Benick, S.W. Glunz, et al. "High efficiency n-type Si solar cells on $Al_2O_3$-passivated boron emitters." Applied Physics Letters, 92(25):253504, June 2008. https://doi.org/10.1063/1.2945287
  17. J. Benick, B. Hoex, et al. "High-Efficiency n-Type Silicon Solar Cells with Front Side Boron Emitter." In Proceedings of the 24th European Photovoltaic Solar Energy Conference, pages 863-870. WIP-Munich, November 2009.
  18. J. Zhao, J. Schmidt, A. Wang, Guangchun Z., B. S. Richards, and M. A. Green. "Performance instability in n-type PERT silicon solar cells." In Proc. 31st IEEE Photovoltaic Specialists Conf. (PVSC), volume 1, pages 923-926 Vol.1, 2003.
  19. A. Richter, J. Benick, A. Kalio, J. Seiffe, M. Horteis, M. Hermle, and S. W. Glunz. "Towards industrial n-type PERT silicon solar cells: rear passivation and metallization scheme." Energy Procedia, 8:479-486, January 2011. https://doi.org/10.1016/j.egypro.2011.06.169
  20. S. Bordihn, P. Wawer, et al. "Large area n-type Cz double side contacted back junction boron emitter solar cell." In Proceedings of the 26th European Photovoltaic Solar Energy Conference and Exhibition, 2011.
  21. V. Mertens, J.W. Muller, et al. "Large Area n-Type Cz Double Side Contact Back Junction Solar Cell with 21.3% Conversion Efficiency." In Proceedings of the 28th European Photovoltaic Solar Energy Conference and Exhibition, 2013.
  22. N. Guillevin, J. Xiong, et al., "High Power n-Type Metal-Wrap-through Cells and Modules Using Industrial Processes." In Proceedings of the 28th European Photovoltaic Solar Energy Conference and Exhibition. WIP, 2013.
  23. D. Kania, H.-J. Krokoszinski, et al., "Pilot Line Production of Industrial High-Efficient Bifacial n-type Silicon Solar Cells with Efficiencies Exceeding 20.6%." In Proceedings of the 28th European Photovoltaic Solar Energy Conference and Exhibition, 2013.
  24. J.-B. Heng, Z. Xu, et al., "Commercialization of Tunnel Oxide Junction Based Cell and Module with Efficiency and Good Reliability." In Proceedingsofthe28thEuropeanPhotovoltaic Solar Energy Conference and Exhibition, 2013.
  25. R. Woehl, M. Rudiger, D. Biro, and J. Wilde. "All-screen-printed back-contact backjunction silicon solar cells with aluminum-alloyed emitter and demonstration of interconnection of point-shaped metalized contacts." Progress in Photovoltaics: Research and Applications, pages n/a-n/a, September 2013.
  26. D. D. Smith, D. Vicente, et al. "Generation III high efficiency lower cost technology: Transition to full scale manufacturing." In Proc. 38th IEEE Photovoltaic Specialists Conf. (PVSC), pages 001594-001597. IEEE, June 2012.
  27. F.Feldmann, M.Bivour.C.Reichel, M.Hermle, S.W.Glunz. "A passivated Rear contact for high efficiency n-type silicon solar cells enabling high Voc and FF>82%."