Skip to main content
Log in

Carrier drift-mobilities and solar cell models for amorphous and nanocrystalline silicon

  • Article
  • Published:
MRS Online Proceedings Library Aims and scope

Abstract

Hole drift mobilities in hydrogenated amorphous silicon (a-Si:H) and nanocrystalline silicon (nc-Si:H) are in the range of 10-3 to 1 cm2/Vs at room-temperature. These low drift mobilities establish corresponding hole mobility limits to the power generation and useful thicknesses of the solar cells. The properties of as-deposited a-Si:H nip solar cells are close to their hole mobility limit, but the corresponding limit has not been examined for nc-Si:H solar cells. We explore the predictions for nc-Si:H solar cells based on parameters and values estimated from hole drift-mobility and related measurements. The indicate that the hole mobility limit for nc-Si:H cells corresponds to an optimum intrinsic-layer thickness of 2-3 µm, whereas the best nc-Si:H solar cells (10% conversion efficiency) have thicknesses around 2 µm.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. M. A. Green, Silicon Solar Cells: Advanced Principles & Practice (University of New South Wales, Sydney, 1995).

    Google Scholar 

  2. E. A. Schiff, Solar Energy Materials and Solar Cells 78, 567 (2003).

    Article  CAS  Google Scholar 

  3. K. Zhu, J. Yang, W. Wang, E. A. Schiff, J. Liang, and S. Guha, in Amorphous and Nanocrystalline Silicon Based Films - 2003, edited by J.R. Abelson, G. Ganguly, H. Matsumura, J. Robertson, E. A. Schiff (Materials Research Society Symposium Proceedings Vol. 762, Pittsburgh, 2003), pp. 297–302.

  4. Jianjun Liang, E. A. Schiff, S. Guha, Baojie Yan, and J. Yang, Appl. Phys. Lett. 88 063512– 063514 (2006).

    Article  Google Scholar 

  5. A. M. Goodman and A. Rose, J. Appl. Phys. 42, 2823 (1971).

    Article  CAS  Google Scholar 

  6. R. S. Crandall, J. Appl. Phys. 55, 4418 (1984).

    Article  CAS  Google Scholar 

  7. V. D. Mihailetchi, J. Wildeman, and P. W. M. Blom, Phys. Rev. Lett. 94, 126602 (2005).

    Article  CAS  Google Scholar 

  8. E. A. Schiff, J. Phys.: Condens. Matter 16, S5265–5275 (2004).

    CAS  Google Scholar 

  9. Qi Wang, Homer Antoniadis, E. A. Schiff, and S. Guha, Phys. Rev. B 47, 9435 (1993).

    Article  Google Scholar 

  10. E. A. Schiff, J. Non-Cryst. Solids 352, 1087 (2006).

    Article  CAS  Google Scholar 

  11. X. Deng and E. A. Schiff, in Handbook of Photovoltaic Science and Engineering, Antonio Luque and Steven Hegedus, editors (John Wiley & Sons, Chichester, 2003), pp. 505 – 565.

  12. Y. Mai, S. Klein, X. Geng, M. Hulsbeck, R. Carius, and F. Finger, Thin Solid Films 501, 272 (2006).

    Article  CAS  Google Scholar 

  13. Y. Mai, S. Klein, R. Carius, J. Wolff, A. Lambertz, and F. Finger, J. Appl. Phys. 97, 114913 (2005).

    Article  Google Scholar 

  14. J. Bailat, D. Domine, R. Schluchter, J. Steinhauser, S. Fay, F. Freitas, C. Bucher, L. Feitknecht, X. Niquille, T. Tscharner, A. Shah, C. Ballif, in Conference Record of the 2006 IEEE 4th World Conference on Photovoltaic Energy Conversion, Vol. 2 (IEEE, 2006), p. 1533.

  15. M. Nath, P. Roci I Cabarrocas, E. V. Johnson, A. Abramov, P. Chatterjee, Thin Solid Films 516, 6974–6978 (2008).

    Article  CAS  Google Scholar 

  16. B. Pieters, H. Stiebig, M. Zeman, and R. A. C. M. M. van Swaaij, J. Appl. Phys. 105, 044502 (2009).

    Article  Google Scholar 

  17. T. Dylla, F. Finger, and E. A. Schiff, Appl. Phys. Lett. 87, 032103–032105 (2005).

    Article  Google Scholar 

  18. T. Dylla, S. Reynolds, R. Carius, F. Finger, J. Non-Cryst. Solids 352, 1093–1096 (2006). Note that these authors use the L = d definition of the drift-mobility (see [29]).

    Article  CAS  Google Scholar 

  19. E. A. Schiff, Phil. Mag. B, in press.

  20. G. Juška, M. Viliūnas, K. Arlauskas, J. Stuchlik, and J. Kočka, Phys. Stat. Sol. (a) 171, 539 (1999).

    Article  CAS  Google Scholar 

  21. G. Juška, K. Arlauskas, J. Stuchlik, and J. İsterbacka, J. Non-Cryst. Solids 352, 1167 (2006).

    Article  CAS  Google Scholar 

  22. C. Droz, M. Goerlitzer, N. Wyrsch, and A. Shah, J. Non-Cryst. Solids 266-269, 319 (2000).

    Article  Google Scholar 

  23. R. Schwarz, P. Sanguino, S. Klynov, M. Fernandes, F. Macarico, P. Louro, and M. Vieira, Mat. Res. Soc. Symp. Proc. Vol. 609, A32.4.1 (2000).

    Article  Google Scholar 

  24. S. Okur, M. Gunes, F. Finger, and R. Carius, Thin Solid Films 501, 137 (2006).

    Article  CAS  Google Scholar 

  25. S. Reynolds, V. Smimov, C. Main, F. Finger, and R. Carius, in Mat. Res. Soc. Symp. Proc. Vol. 808 (Materials Research Society, Pittsburgh, 2004), p. A.5.7.1.

  26. The temperature-dependence of the bandgap for a-Si:H is -0.47 meV/K [4]. For nc-Si:H we’ve used the value for c-Si, which is -0.27 meV/K near room-temperature; see J. Weber, in Properties of Crystalline Silicon, R. Hull, ed., Institution of Engineering and Technology, Stevenage, 1999, pp. 391–393.

  27. S. Saripalli, P. Sharma, P. Reusswig, V. Dalal, J. Non-Cryst. Solids 354, 2426 (2008).

    Article  CAS  Google Scholar 

  28. B. Yan, G. Yue, J. Yang, S. Guha, D. L. Williamson, D. Han, and C.-S. Jiang, Appl. Phys. Lett. 85, 1955 (2004).

    Article  CAS  Google Scholar 

  29. Most experimental papers cited here calculate the drift-mobility assuming that the mean displacement L at the transit-time is half the sample thickness d (L = d /2) [9]. Some experimenters use the older expression L = d (cf. [18]), which yields mobilities that are twice as large.

  30. This expression in square brackets differs slightly from eq. (4) of ref. [8] because that reference implicitly assumed that the product N VbT is temperature-independent. This assumption requires that the temperature-dependence of b T compensates that of N V, which seems arbitrary. The fittings to drift-mobilities are not substantially affected; this can be seen in Fig. 6, where the fitting Zhu03 seems satisfactory with the original parameters.

  31. S. Dinca, G. Ganguly, Z. Lu, E. A. Schiff, V. Vlahos, C. R. Wronski, Q. Yuan, in Amorphous and Nanocrystalline Silicon Based Films - 2003, edited by J.R. Abelson, G. Ganguly, H. Matsumura, J. Robertson, E. A. Schiff (Materials Research Society Symposium Proceedings Vol. 762, Pittsburgh, 2003), pp. 345–350.

  32. E. A. Schiff, Phys. Rev. B 24, pp. 6189 (1981).

    Article  Google Scholar 

  33. Q. Gu, E. A. Schiff, S. Grebner, F. Wang, and R. Schwarz, Phys. Rev. Lett. 76, 3196 (1996).

    Article  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Schiff, E.A. Carrier drift-mobilities and solar cell models for amorphous and nanocrystalline silicon. MRS Online Proceedings Library 1153, 1501 (2008). https://doi.org/10.1557/PROC-1153-A15-01

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1557/PROC-1153-A15-01

Navigation