Advertisement

Journal of Computational Electronics

, Volume 18, Issue 4, pp 1152–1161 | Cite as

Kinetic Monte Carlo simulation of transport in amorphous silicon passivation layers in silicon heterojunction solar cells

  • Pradyumna MuralidharanEmail author
  • Stephen M. Goodnick
  • Dragica Vasileska
Article
  • 120 Downloads

Abstract

Silicon heterojunction solar cell device structures use carrier-selective contacts to maximize collection of photogenerated carriers. The carrier-selective contact structure consists of doped hydrogenated amorphous silicon and intrinsic hydrogenated amorphous silicon [a-Si:H(i)]. In this structure, the a-Si:H(i) layer plays a crucial role as it passivates the heterointerface between the doped hydrogenated amorphous silicon and the crystalline silicon enabling the solar cell to achieve high device efficiencies. However, the a-Si:H(i) layer also creates a potential barrier to photogenerated carriers which obstructs them from getting collected. Previously, experimental studies in the literature have predicted that the photogenerated carriers cross the barrier by defect-assisted transport (hopping). Traditionally, theoretical models that are employed to study the electrical characteristics of silicon heterojunction solar cells do not provide any great insight into the transport of carriers via defects. In this paper, we present an in-house developed kinetic Monte Carlo that simulates the transport of photogenerated holes through the band tail defect states in the a-Si:H(i) layer. This is done primarily by defining transition rates associated with carrier-defect interactions. We conduct simulations to understand the impact of the properties (optical phonon energy, defect density, etc.) of the a-Si:H(i) layer on transport of photogenerated holes. Our simulations indicate that multi-phonon injection and hopping processes assist photogenerated holes to cross the a-Si:H(i) layer, which is in agreement with experimental findings.

Keywords

Silicon heterojunction solar cells Kinetic Monte Carlo Defect-assisted transport Device modeling 

Notes

Acknowledgements

This material is based upon work primarily supported by the Engineering Research Center Program of the National Science Foundation and the Office of Energy Efficiency and Renewable Energy of the Department of Energy under NSF Cooperative Agreement No. EEC‐1041895. Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect those of the National Science Foundation or Department of Energy.

References

  1. 1.
    Richter, A., Hermle, M., Glunz, S.: Crystalline silicon solar cells reassessment of the limiting efficiency for crystalline silicon solar cells. IEEE J. Photovolt. 3(4), 1184–1191 (2013)CrossRefGoogle Scholar
  2. 2.
    Battaglia, C., Cuevas, A., De Wolf, S.: High-efficiency crystalline silicon solar cells: status and perspectives. Energy Environ. Sci. 9, 1552–1576 (2016)CrossRefGoogle Scholar
  3. 3.
    Yoshikawa, K., et al.: Silicon heterojunction solar cell with interdigitated back contacts for a photoconversion efficiency over 26%. Nat. Energy 2(5), 17032 (2017)CrossRefGoogle Scholar
  4. 4.
    Cuevas, A., Allen, T., Bullock, J.: Skin care for healthy silicon solar cells. In: 2015 IEEE 42nd Photovoltaic Specialist Conference, no. 1, pp. 1–6 (2015)Google Scholar
  5. 5.
    Taguchi, M., Terakawa, A., Maruyama, E., Tanaka, M.: Obtaining a higher voc in HIT cells. Prog. Photovolt. Res. Appl. 13(6), 481–488 (2005)CrossRefGoogle Scholar
  6. 6.
    Powell, M., Deane, S.: Defect-pool model and the hydrogen density of states in hydrogenated amorphous silicon. Phys. Rev. B 53(15), 10121–10132 (1996)CrossRefGoogle Scholar
  7. 7.
    Powell, M.J., Deane, S.C.: Improved defect-pool model for charged defects in amorphous silicon. Phys. Rev. B 48(15), 10815–10827 (1993)CrossRefGoogle Scholar
  8. 8.
    Taguchi, M., Maruyama, E., Tanaka, M.: Temperature dependence of amorphous/crystalline silicon heterojunction solar cells. Jpn. J. Appl. Phys. 47(2), 814–818 (2008)CrossRefGoogle Scholar
  9. 9.
    Crandall, R.S., Iwaniczko, E., Li, J.V., Page, M.R.: A comprehensive study of hole collection in heterojunction solar cells. J. Appl. Phys. 112(9), 093713 (2012)CrossRefGoogle Scholar
  10. 10.
    Lachaume, R., Favre, W., Scheiblin, P., Garros, X.: Influence of a-Si:H/ITO interface properties on performance of heterojunction solar cells. Energy Procedia 38, 770–776 (2013)CrossRefGoogle Scholar
  11. 11.
    Luppina, P., Lugli, P., Goodnick, S.M.: Modeling of silicon heterojunction solar cells. In: 2015 IEEE 42nd Photovoltaic Specialist Conference, pp. 1–6 (2015)Google Scholar
  12. 12.
    Varache, R., Kleider, J.P., Gueunier-Farret, M.E., Korte, L.: Silicon heterojunction solar cells: optimization of emitter and contact properties from analytical calculation and numerical simulation. Mater. Sci. Eng. B Solid-State Mater. Adv. Technol. 178(9), 593–598 (2013)CrossRefGoogle Scholar
  13. 13.
    Yang, X., Zheng, P., Bi, Q., Weber, K.: Silicon heterojunction solar cells with electron selective TiOx contact. Sol. Energy Mater. Sol. Cells 150, 32–38 (2016)CrossRefGoogle Scholar
  14. 14.
    Bivour, M., Zähringer, F., Ndione, P., Hermle, M.: Sputter-deposited WOx and MoOx for hole selective contacts. Energy Procedia 124, 400–405 (2017)CrossRefGoogle Scholar
  15. 15.
    Battaglia, C., et al.: Hole selective MoOx contact for silicon solar cells. Nano Lett. 14(2), 967–971 (2014)CrossRefGoogle Scholar
  16. 16.
    Messmer, C., Bivour, M., Schön, J., Glunz, S.W., Hermle, M.: Numerical simulation of silicon heterojunction solar cells featuring metal oxides as carrier-selective contacts. IEEE J. Photovolt. J. Photovolt. 8(2), 456–464 (2018)CrossRefGoogle Scholar
  17. 17.
    Vijayan, R.A., et al.: Hole-collection mechanism in passivating metal-oxide contacts on Si solar cells: insights from numerical simulations. IEEE J. Photovolt. 8(2), 473–482 (2018)CrossRefGoogle Scholar
  18. 18.
    Campa, A., Valla, A., Brecl, K., Smole, F., Munoz, D., Topic, M.: Multiscale modeling and back contact design of bifacial silicon heterojunction solar cells. IEEE J. Photovolt. 8(1), 89–95 (2018)CrossRefGoogle Scholar
  19. 19.
    Krc, J., et al.: Potential of thin-film silicon solar cells by using high haze TCO superstrates. Thin Solid Films 518(11), 3054–3058 (2010)CrossRefGoogle Scholar
  20. 20.
    Martin-bragado, I., Borges, R., Pablo, J., Jaraiz, M.: Progress in materials science kinetic monte carlo simulation for semiconductor processing: a review. Prog. Mater Sci. 92, 1–32 (2018)CrossRefGoogle Scholar
  21. 21.
    Carlo, M., Jegert, G., Kersch, A., Weinreich, W., Schröder, U., Lugli, P.: Modeling of leakage currents in high-k dielectrics: three-dimensional approach via kinetic Monte Carlo. Appl. Phys. Let 96, 062113 (2010)CrossRefGoogle Scholar
  22. 22.
    van der Holst, J.J.M.: Three-Dimensional Modeling of Charge Transport, Injection and Recombination in Organic Light-Emitting Diodes. Technische Universiteit Eindhoven, Eindhoven (2010)Google Scholar
  23. 23.
    Albes, T., Popescu, B., Popescu, D., Loch, M., Arca, F., Lugli, P.: Kinetic Monte Carlo modeling of low-bandgap polymer solar cells. In: 2014 IEEE 40th Photovoltaic Specialist Conference, pp. 57–62 (2014)Google Scholar
  24. 24.
    Stangl, R., Leendertz, C., Haschke, J.: Numerical Simulation of Solar Cells and Solar Cell Characterization Methods: The Open-Source on Demand Program AFORS-HET (2010)Google Scholar
  25. 25.
    Street, R.A.: Hydrogenated Amorphous Silicon. Cambridge University Press, Cambridge (1991)CrossRefGoogle Scholar
  26. 26.
    Muralidharan, P., Ghosh, K., Vasileska, D., Goodnick, S.M.: Hot hole transport in a-Si/c-Si heterojunction solar cells. In: 2014 IEEE 40th Photovoltaic Specialist Conference (PVSC) (2014)Google Scholar
  27. 27.
    Gillespie, D.T.: A general method for numerically simulating the stochastic time evolution of coupled chemical reactions. J. Comput. Phys. 22(4), 403–434 (1976)MathSciNetCrossRefGoogle Scholar
  28. 28.
    Lundström, I., Svensson, C.: Tunneling to traps in insulators. J. Appl. Phys. 43(12), 5045–5047 (1972)CrossRefGoogle Scholar
  29. 29.
    Muralidharan, P., Bowden, S., Goodnick, S.M., Vasileska, D.: A kinetic Monte Carlo approach to study transport in amorphous silicon HIT cells. In: 2015 IEEE 42nd Photovoltaic Specialist Conference (PVSC), pp. 743–758 (2015)Google Scholar
  30. 30.
    Herrmann, M., Schenk, A.: Field and high-temperature dependence of the long term charge loss in erasable programmable read only memories: measurements and modeling. J. Appl. Phys. 77(9), 4522–4540 (1995)CrossRefGoogle Scholar
  31. 31.
    Muralidharan, P., Vasileska, D., Goodnick, S.M., Bowden, S.: A kinetic Monte Carlo study of defect assisted transport in silicon heterojunction solar cells. Phys. Status Solidi C Curr Top. Solid State Phys. 12(9–11), 1198–1200 (2015)CrossRefGoogle Scholar
  32. 32.
    Miller, A., Abrahams, E.: Impurity conduction at low concentrations. Phys. Rev. 120(3), 745–755 (1960)CrossRefGoogle Scholar
  33. 33.
    Frenkel, J.: On pre-breakdown phenomena in insulators and electronic semi-conductors. Phys. Rev. 54(8), 647–648 (1938)CrossRefGoogle Scholar
  34. 34.
    Hartke, J.L.: The three-dimensional Poole–Fenkel effect. J. Appl. Phys. 39(10), 4871–4873 (1968)CrossRefGoogle Scholar
  35. 35.
    Jegert, G.C.: Modeling of Leakage Currents in High-k Dielectrics. Technische Universitat Munchen, Munich (2012)Google Scholar
  36. 36.
    Stückelberger, M.E.: Hydrogenated Amorphous Silicon : Impact of Process Conditions on Material Properties and Solar Cell Efficiency. Ecole Polytechnique Federale De Lausanne, Lausanne (2014)Google Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Arizona State UniversityTempeUSA

Personalised recommendations