Performance and Durability of Electrically Conductive Tape for Shingled Si Heterojunction Technology Cells

Peter Hacke, David Miller, Daniel Pierpont, Tianyu Wu

Research output: Contribution to journalArticlepeer-review


Electrically conductive tape (ECT) was characterized and used to assemble shingled cell strings at low temperature to achieve high reliability Pb- and Ag-free interconnections. The volume resistivity for two considered ECTs are 0.13 +/- 0.06 and 0.47 +/- 0.20 and specific contact resistances, 6.85 +/- 2.00 and 6.30 +/- 0.37 using the emerging IEC 62788-8-1 Technical Specification for assessment of electrically conductive adhesives (ECA). Durability and performance of the technology in glass-glass mini modules were evaluated with temperature cycling, damp heat testing, and combined-accelerated stress testing (CAST). Through temperature cycling (-40 degrees C to 85 degrees C) applying five times the mini module short-circuit current in forward bias and in the multi climate CAST protocol, there was negligible degradation of fill factor after replacing connectors at the modules' cable leads; however, CAST resulted in short circuit current loss attributed to degradation in light collection by the cells, not the ECT. The IEC 61215-2 85 degrees C, 85% relative humidity damp heat testing showed susceptibility of the HJT cells to effects of humidity in the electroluminescence intensity around the module perimeter that degraded power performance by 4% (relative). Contrasting the IEC 61215-2 qualification testing-based damp heat testing with CAST, factors such as the optical stress of CAST may precipitate the degradation of the modules whereas the humidity levels and duration of IEC 61215-2 damp heat testing may lead to excessive levels of humidity diffused into the modules, potentially resulting in degradation that is unrepresentative of the field.
Original languageAmerican English
JournalProgress in Photovoltaics: Research and Applications
StatePublished - 2023

NREL Publication Number

  • NREL/JA-5K00-86977


  • combined-accelerated stress testing
  • durability
  • electrically conductive adhesive
  • electrically conductive tape
  • photovoltaic cells
  • photovoltaic modules
  • reliability
  • shingled cells


Dive into the research topics of 'Performance and Durability of Electrically Conductive Tape for Shingled Si Heterojunction Technology Cells'. Together they form a unique fingerprint.

Cite this