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Energy Express

Energy Express

  • Editor: Christian Seassal
  • Vol. 22, Iss. S5 — Aug. 25, 2014
  • pp: A1270–A1277

Advancing tandem solar cells by spectrally selective multilayer intermediate reflectors

Andre Hoffmann, Ulrich W. Paetzold, Chao Zhang, Tsvetelina Merdzhanova, Andreas Lambertz, Carolin Ulbrich, Karsten Bittkau, and Uwe Rau  »View Author Affiliations

Optics Express, Vol. 22, Issue S5, pp. A1270-A1277 (2014)

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Thin-film silicon tandem solar cells are composed of an amorphous silicon top cell and a microcrystalline silicon bottom cell, stacked and connected in series. In order to match the photocurrents of the top cell and the bottom cell, a proper photon management is required. Up to date, single-layer intermediate reflectors of limited spectral selectivity are applied to match the photocurrents of the top and the bottom cell. In this paper, we design and prototype multilayer intermediate reflectors based on aluminum doped zinc oxide and doped microcrystalline silicon oxide with a spectrally selective reflectance allowing for improved current matching and an overall increase of the charge carrier generation. The intermediate reflectors are successfully integrated into state-of-the-art tandem solar cells resulting in an increase of overall short-circuit current density by 0.7 mA/cm2 in comparison to a tandem solar cell with the standard single-layer intermediate reflector.

© 2014 Optical Society of America

OCIS Codes
(040.5350) Detectors : Photovoltaic
(350.4238) Other areas of optics : Nanophotonics and photonic crystals

ToC Category:
Light Trapping for Photovoltaics

Original Manuscript: February 17, 2014
Revised Manuscript: April 17, 2014
Manuscript Accepted: April 17, 2014
Published: July 28, 2014

Andre Hoffmann, Ulrich W. Paetzold, Chao Zhang, Tsvetelina Merdzhanova, Andreas Lambertz, Carolin Ulbrich, Karsten Bittkau, and Uwe Rau, "Advancing tandem solar cells by spectrally selective multilayer intermediate reflectors," Opt. Express 22, A1270-A1277 (2014)

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  1. A. Vos, “Detailed balance limit of the efficiency of tandem solar cells,” J. Phys. D Appl. Phys. 13(5), 839–846 (1980). [CrossRef]
  2. J. Meier, S. Dubail, R. Platz, P. Torres, U. Kroll, J. A. Anna Selvan, N. Pellaton Vaucher, C. Hofa, D. Fischera, H. Keppnera, R. Flückigera, A. Shaha, V. Shklover, and K.-D. Ufert, “Towards high-efficiency thin-film silicon solar cells with the ‘micromorph’ concept,” Sol. Energy Mater. Sol. Cells 49(1–4), 35–44 (1997). [CrossRef]
  3. C. Ulbrich, C. Zahren, A. Gerber, B. Blank, T. Merdzhanova, A. Gordijn, and U. Rau, “Matching of silicon thin-film tandem solar cells for maximum power output,” Int. J. Photoenergy 2013, 314097 (2013). [CrossRef]
  4. J. Meier, S. Dubail, S. Golay, U. Kroll, S. Fay, E. Vallat-Sauvain, J. Feitknecht, J. Dubail, and A. Shah, “Microcrystalline silicon and the impact on micromorph tandem solar cells,” Sol. Energy Mater. Sol. Cells 74(1-4), 457–467 (2002). [CrossRef]
  5. B. Rech, T. Repmann, M. N. van den Donker, M. Berginski, T. Kilper, J. Hüpkes, S. Calman, H. Stiebig, and S. Wieder, “Challenges in microcrystalline silicon based solar cell technology,” Thin Solid Films 511–512, 548–555 (2006). [CrossRef]
  6. D. L. Staebler and C. R. Wronski, “Reversible conductivity changes in discharge–produced amorphous Si,” Appl. Phys. Lett. 31(4), 292–294 (1977). [CrossRef]
  7. K. Yamamoto, A. Nakajima, M. Yoshimi, T. Sawada, S. Fukuda, T. Suezaki, M. Ichikawa, Y. Koi, M. Goto, H. Takata, T. Sasaki, and Y. Tawada, “Novel hybrid thin film silicon solar cell and module,” in 3rd World Conf. on PV Energy Conv. (2003).
  8. P. Buehlmann, J. Bailat, D. Dominé, A. Billet, F. Meillaud, A. Feltrin, and C. Ballif, “In situ silicon oxide based intermediate reflector for thin–film silicon micromorph solar cells,” Appl. Phys. Lett. 91(14), 143505 (2007). [CrossRef]
  9. A. Lambertz, T. Grundler, and F. Finger, “Hydrogenated amorphous silicon oxide containing a microcrystalline silicon phase and usage as an intermediate reflector in thin–film silicon solar cells,” J. Appl. Phys. 109(11), 113109 (2011). [CrossRef]
  10. A. Lambertz, V. Smirnov, T. Merdzhanova, K. Ding, S. Haas, G. Jost, R. E. I. Schropp, F. Finger, and U. Rau, “Microcrystalline silicon–oxygen alloys for application in silicon solar cells and modules,” Sol. Energy Mater. Sol. Cells 119, 134–143 (2013). [CrossRef]
  11. J. Üpping, A. Bielawny, R. B. Wehrspohn, T. Beckers, R. Carius, U. Rau, S. Fahr, C. Rockstuhl, F. Lederer, M. Kroll, T. Pertsch, L. Steidl, and R. Zentel, “Three-dimensional photonic crystal intermediate reflectors for enhanced light-trapping in tandem solar cells,” Adv. Mater. 23(34), 3896–3900 (2011). [CrossRef] [PubMed]
  12. G. Jost, T. Merdzhanova, T. Zimmermann, and J. Hüpkes, “Process monitoring of texture-etched high-rate ZnO:Al front contacts for silicon thin-film solar cells,” Thin Solid Films 532, 66–72 (2013). [CrossRef]
  13. J. Krc, F. Smole, and M. Topic, “Optical simulation of the role of reflecting interlayers in tandem micromorph silicon solar cells,” Sol. Energy Mater. Sol. Cells 86(4), 537–550 (2005). [CrossRef]
  14. A. Bielawny, C. Rockstuhl, F. Lederer, and R. B. Wehrspohn, “Intermediate reflectors for enhanced top cell performance in photovoltaic thin-film tandem cells,” Opt. Express 17(10), 8439–8446 (2009). [CrossRef] [PubMed]
  15. P. G. O’Brien, A. Chutinan, K. Leong, N. P. Kherani, G. A. Ozin, and S. Zukotynski, “Photonic crystal intermediate reflectors for micromorph solar cells: A comparative study,” Opt. Express 18(5), 4478–4490 (2010). [CrossRef] [PubMed]
  16. P. G. O’Brien, Y. Yang, A. Chutinan, P. Mahtani, K. Leong, D. P. Puzzo, L. D. Bonifacio, C.-W. Lina, G. A. Ozin, and N. P. Kherani, “Selectively transparent and conducting photonic crystal solar spectrum splitters made of alternating sputtered indium–tin oxide and spin–coated silica nanoparticle layers for enhanced photovoltaics,” Sol. Energy Mater. Sol. Cells 102, 173–183 (2012). [CrossRef]
  17. S. Y. Myong and L. S. Jeon, “Improved light trapping in thin-film silicon solar cells via alternated n-type silicon oxide reflectors,” Sol. Energy Mater. Sol. Cells 119, 77–83 (2013). [CrossRef]
  18. A. Hoffmann, U. W. Paetzold, T. Merdzhanova, A. Lambertz, O. Höhn, C. Ulbrich, K. Bittkau, and U. Rau, “Spectrally selective intermediate reflectors for tandem thin-film silicon solar cells,” Proc. SPIE 8823, 882305 (2013). [CrossRef]
  19. W. Theiss, “SCOUT Software Package,” http://www.mtheiss.com .
  20. P. Bienstman and R. Baets, “Optical modelling of photonic crystals and VCSELs using eigenmode expansion and perfectly matched layers,” Opt. Quantum Electron. 33(4/5), 327–341 (2001). [CrossRef]
  21. A. F. Oskooi, D. Roundy, M. Ibanescu, P. Bermel, J. D. Joannopoulos, and S. G. Johnson, “MEEP: A flexible free–software package for electromagnetic simulations by the FDTD method,” Comput. Phys. Commun. 181(3), 687–702 (2010). [CrossRef]
  22. C. Rockstuhl, F. Lederer, K. Bittkau, T. Beckers, and R. Carius, “The impact of intermediate reflectors on light absorption in tandem solar cells with randomly textured surfaces,” Appl. Phys. Lett. 94(21), 211101 (2009). [CrossRef]
  23. U. W. Paetzold, E. Moulin, B. E. Pieters, U. Rau, and R. Carius, “Optical simulations of microcrystalline silicon solar cells applying plasmonic reflection grating back contacts,” J. Photon. Ener. 2(1), 027002 (2012). [CrossRef]
  24. D. Lockau, L. Zschiedrich, S. Burger, F. Schmidt, F. Ruske, and B. Rech, “Rigorous optical simulation of light management in crystalline silicon thin–film solar cells with rough textured interfaces,” Proc. SPIE 7933, 79330M (2011). [CrossRef]
  25. J. D. Joannopoulos, P. R. Villeneuve, and S. Fan, “Photonic crystals: Putting a new twist on light,” Nature 386(6621), 143–149 (1997). [CrossRef]
  26. H. A. Macleod, Thin-Film Optical Filters, 3rd ed. (Taylor and Francis, 2001).
  27. S. Fahr, C. Rockstuhl, and F. Lederer, “The interplay of intermediate reflectors and randomly textured surfaces in tandem solar cells,” Appl. Phys. Lett. 97(17), 173510 (2010). [CrossRef]

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