Dielectric Stack Passivation on Boron- and Phosphorus-Diffused Surfaces and 20% Efficient PERT Cell on n-CZ Silicon Substrate

Bill Nemeth, Hao Chih Yuan, Matthew Page, Vincenzo Lasalvia, Rohan Chaukulkar, Lynn Gedvilas, Jian V. Li, Paul Stradins

Research output: Contribution to conferencePaperpeer-review

1 Scopus Citations


We present a surface passivation study of a B-diffused emitter and P-diffused back-surface field (BSF) of n-CZ Si substrates. The optimized passivation layers are subsequently incorporated into a 20%-efficient passivated emitter, rear totally-diffused (PERT) cell with Voc of 672 mV. On the P-diffused, concentrated KOH-planarized BSF side, we compare different passivating plasma enhanced chemical vapor deposition (PECVD) SiNx layer compositions. We demonstrate that a favorable combination of best passivation quality is achieved by a stack of thermal oxide grown at ∼700°C, followed by a bilayer SiNx, consisting of stoichiometric PECVD nitride and capped with Si-rich nitride, or H-dilution nitride. The stack results in surface passivation quality of Jo ∼ 17 fA/cm2 for bilayer SiNx and 14 fA/cm2 for H-SiNx on lightly P-doped BSF, and is very resistive to HF-containing wet etches. Surface preparation, deposition parameters, and post-growth annealing collaborate to define the effectiveness of the passivation. Their optimization is critical for integration of SiNx:H into our high-efficiency solar cells. On the B-diffused textured emitter side, we use atomic layer deposition (ALD)-deposited Al2O3 for surface passivation and low-temperature stoichiometric PECVD SiNx for the anti-reflection coating. We discuss deposition conditions and thermal treatments for both ALD Al2O3 and PECVD nitride that result in the optimized passivation resulting in Jo ∼ 52 fA/cm2 and that prevent the blistering of the film.

Original languageAmerican English
Number of pages5
StatePublished - 15 Oct 2014
Event40th IEEE Photovoltaic Specialist Conference, PVSC 2014 - Denver, United States
Duration: 8 Jun 201413 Jun 2014


Conference40th IEEE Photovoltaic Specialist Conference, PVSC 2014
Country/TerritoryUnited States

Bibliographical note

Publisher Copyright:
© 2014 IEEE.

NREL Publication Number

  • NREL/CP-5J00-61344


  • passivation
  • silicon dioxide
  • silicon nitride
  • silicon solar cells


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