Ion implantation for poly-Si passivated back-junction back-contacted solar cells

Research output: Contribution to journalArticleResearchpeer review

Authors

  • Udo Römer
  • Robby Peibst
  • Tobias Ohrdes
  • Bianca Lim
  • Jan Krügener
  • Tobias Wietler
  • Rolf Brendel

External Research Organisations

  • Institute for Solar Energy Research (ISFH)
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Details

Original languageEnglish
Article number7006679
Pages (from-to)507-514
Number of pages8
JournalIEEE journal of photovoltaics
Volume5
Issue number2
Publication statusPublished - 1 Mar 2015

Abstract

We study ion implantation for patterned doping of back-junction back-contacted solar cells with polycrystalline-monocrystalline Si junctions. In particular, we investigate the concept of counterdoping, that is, a process of first implanting a blanket emitter and afterward locally overcompensating the emitter by applying masked ion implantation for the back surface field (BSF) species. On planar test structures with blanket implants, we measure saturation current densities J0,poly of down to 1.0 ± 1.1 fA/cm2 for wafers passivated with phosphorus-implanted poly-Si layers and 4.4 ± 1.1 fA/cm2 for wafers passivated with boron-implanted poly-Si layers. The corresponding implied pseudofill factors pFFimpl. are 87.3% and 84.6%, respectively. Test structures fabricated with the counterdoping process applied on a full area also exhibit excellent recombination behavior (J0,poly = 0.9 ± 1.1 fA/cm2, pFFimpl. = 84.7%). By contrast, the samples with patterned counterdoped regions exhibit a far worse recombination behavior dominated by a recombination mechanism with an ideality factor n > 1. A comparison with the blanket-implanted test structures points to recombination in the space charge region inside the highly defective poly-Si layer. Consequently, we suggest introducing an undoped region between emitter and BSF in order to avoid the formation of p+/n+ junctions in poly-Si.

Keywords

    Back contact solar cells, carrier selective contacts, ion implantation, photovoltaic cells, solar energy

ASJC Scopus subject areas

Sustainable Development Goals

Cite this

Ion implantation for poly-Si passivated back-junction back-contacted solar cells. / Römer, Udo; Peibst, Robby; Ohrdes, Tobias et al.
In: IEEE journal of photovoltaics, Vol. 5, No. 2, 7006679, 01.03.2015, p. 507-514.

Research output: Contribution to journalArticleResearchpeer review

Römer, U, Peibst, R, Ohrdes, T, Lim, B, Krügener, J, Wietler, T & Brendel, R 2015, 'Ion implantation for poly-Si passivated back-junction back-contacted solar cells', IEEE journal of photovoltaics, vol. 5, no. 2, 7006679, pp. 507-514. https://doi.org/10.1109/jphotov.2014.2382975
Römer, U., Peibst, R., Ohrdes, T., Lim, B., Krügener, J., Wietler, T., & Brendel, R. (2015). Ion implantation for poly-Si passivated back-junction back-contacted solar cells. IEEE journal of photovoltaics, 5(2), 507-514. Article 7006679. https://doi.org/10.1109/jphotov.2014.2382975
Römer U, Peibst R, Ohrdes T, Lim B, Krügener J, Wietler T et al. Ion implantation for poly-Si passivated back-junction back-contacted solar cells. IEEE journal of photovoltaics. 2015 Mar 1;5(2):507-514. 7006679. doi: 10.1109/jphotov.2014.2382975
Römer, Udo ; Peibst, Robby ; Ohrdes, Tobias et al. / Ion implantation for poly-Si passivated back-junction back-contacted solar cells. In: IEEE journal of photovoltaics. 2015 ; Vol. 5, No. 2. pp. 507-514.
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AU - Römer, Udo

AU - Peibst, Robby

AU - Ohrdes, Tobias

AU - Lim, Bianca

AU - Krügener, Jan

AU - Wietler, Tobias

AU - Brendel, Rolf

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