Diffusion profiles beneath silicon heterojunction contacts reduce contact resistivity and increase efficiency

William Weigand, Pradyumna Muralidharan, Daniel Chen, Anastasia Soeriyadi, Bruno Vicari Stefani, Brett Hallam, Stephen M. Goodnick, Zhengshan J. Yu, Zachary C. Holman

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Silicon heterojunction solar cells have historically had high open-circuit voltages due to the passivation provided by the intrinsic amorphous silicon layer, yet this same layer can also limit the fill factor of these devices. In comparison, diffused-junction solar cells have traditionally had higher fill factors than silicon heterojunction solar cells due to the low contact resistivity between the metal and doped surface of the wafer. By combining these two device architectures, it is possible to increase the fill factor - through a reduction in contact resistivity - while also maintaining a high open-circuit voltage with the passivating contact. In particular, we show through simulation and experiment that adding a diffusion under an amorphous silicon heterojunction contact reduces contact resistivity by approximately 0.04\ \Omega\text{cm}^{2}, and, in contrast to standard silicon heterojunction devices, the contact resistivity does not increase with the intrinsic amorphous silicon thickness. In addition, this contact allows for an efficiency boost of 0.56-0.85% absolute over our standard device structure.

Original languageEnglish (US)
Title of host publication2020 47th IEEE Photovoltaic Specialists Conference, PVSC 2020
PublisherInstitute of Electrical and Electronics Engineers Inc.
Number of pages4
ISBN (Electronic)9781728161150
StatePublished - Jun 14 2020
Event47th IEEE Photovoltaic Specialists Conference, PVSC 2020 - Calgary, Canada
Duration: Jun 15 2020Aug 21 2020

Publication series

NameConference Record of the IEEE Photovoltaic Specialists Conference
ISSN (Print)0160-8371


Conference47th IEEE Photovoltaic Specialists Conference, PVSC 2020


  • contact resistivity
  • diffusion
  • passivation
  • silicon homo-heterojunction

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Industrial and Manufacturing Engineering
  • Electrical and Electronic Engineering


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