Modified laser-fired contact process for efficient PERC solar cells

Jae Myeong Choi, Beomsic Jung, Jong Keuk Park, Won Mok Kim, Doh Kwon Lee, Jeung hyun Jeong, Taek Sung Lee, Jea Young Choi, Byeong Kwon Ju, Inho Kim

Research output: Contribution to journalArticle

Abstract

A laser-fired contact (LFC) process is one of the techniques for making local electrical contacts at the rear side of passivated emitter and rear cell (PERC) solar cells. In the LFC process, opening of the passivated dielectric layers and alloying of Si and Al need to be made in a single step laser process. For this reason, the LFC process is accompanied by the loss of Al and the laser damage to the Si wafer. In this study, we present a novel multistep LFC process combining the conventional LFC and laser-induced forward transfer (LIFT) processes. The modified LFC scheme we proposed consists of three steps: (a) opening of the passivation layers and partial alloying of Al-Si, (b) additional deposition of Al on the local contact holes, and (c) post laser firing of the transferred Al. Applying the modified LFC process to the PERC cells of 1.0 cm2 of area, we demonstrate the effective recombination velocity of the laser-processed wafers can be remarkably reduced while maintaining the low contact resistance. The best of the PERC solar cell fabricated by the modified LFC process exhibited an efficiency of 19.5% while the conventional LFC-PERC cell showed 18.6%. The efficiency gains of the modified LFC-PERC cells was largely contributed by the enhanced open circuit voltage (Voc) and fill factor (FF).

Original languageEnglish
JournalProgress in Photovoltaics: Research and Applications
DOIs
Publication statusAccepted/In press - 2019 Jan 1

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Keywords

  • contact resistance
  • crystalline silicon solar cells
  • implied V
  • laser-fried contact
  • PERC cell
  • pulsed laser

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Renewable Energy, Sustainability and the Environment
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

Cite this

Choi, J. M., Jung, B., Park, J. K., Kim, W. M., Lee, D. K., Jeong, J. H., Lee, T. S., Choi, J. Y., Ju, B. K., & Kim, I. (Accepted/In press). Modified laser-fired contact process for efficient PERC solar cells. Progress in Photovoltaics: Research and Applications. https://doi.org/10.1002/pip.3187