Improving surface passivation on very thin substrates for high efficiency silicon heterojunction solar cells

Pradeep Balaji, William J. Dauksher, Stuart G. Bowden, André Augusto

Research output: Contribution to journalArticlepeer-review

24 Scopus citations


Silicon solar cells are now less than 3% absolute from the theoretical efficiency limit. Advanced passivated contact architectures have demonstrated surface saturation current densities close to 1 fA/cm2. We have optimized the thin intrinsic hydrogenated amorphous silicon layer by controlling the deposition temperature and the silane-to-hydrogen dilution ratio. Thin wafers were used as a testbed to increase the sensitivity to surface passivation. By optimizing the intrinsic layer, we reduced the surface saturation current densities from 1.7 fA/cm2 to 0.6 fA/cm2 on textured wafers with thicknesses ranging between 40 and 180 μm. Implied open-circuit voltages over 760 mV were accomplished on p-i/c-Si/i-n structures deposited on n-type CZ wafers with wafer thicknesses below 50 μm. Further, we demonstrated experimentally the potential of using very thin wafers by manufacturing screen-printed silicon heterojunction solar cells on 40 μm thick standalone wafers while achieving an efficiency of 20.48%.

Original languageEnglish (US)
Article number110715
JournalSolar Energy Materials and Solar Cells
StatePublished - Oct 2020


  • Heterojunction solar cells
  • Open circuit voltage
  • Saturation current density
  • Silicon
  • Surface passivation
  • Thin PV cells

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Renewable Energy, Sustainability and the Environment
  • Surfaces, Coatings and Films


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