Comparison of Photoluminescence Imaging on Starting Multi-Crystalline Silicon Wafers to Finished Cell Performance

Steve Johnston, Fei Yan, David Dorn, Katherine Zaunbrecher, Mowafak Al-Jassim, Omar Sidelkheir, Kamel Ounadjela

Research output: Contribution to conferencePaperpeer-review

6 Scopus Citations


Photoluminescence (PL) imaging techniques can be applied to multicrystalline silicon wafers throughout the manufacturing process. Both band-to-band PL and defect-band emissions, which are longer-wavelength emissions from sub-bandgap transitions, are used to characterize wafer quality and defect content on starting multicrystalline silicon wafers and neighboring wafers processed at each step through completion of finished cells. Both PL imaging techniques spatially highlight defect regions that represent dislocations and defect clusters. The relative intensities of these imaged defect regions change with processing. Band-to-band PL on wafers in the later steps of processing shows good correlation to cell quality and performance. The defect band images show regions that change relative intensity through processing, and better correlation to cell efficiency and reverse-bias breakdown is more evident at the starting wafer stage as opposed to later process steps. We show that thermal processing in the 200°-400°C range causes impurities to diffuse to different defect regions, changing their relative defect band emissions.

Original languageAmerican English
Number of pages6
StatePublished - 2012
Event38th IEEE Photovoltaic Specialists Conference, PVSC 2012 - Austin, TX, United States
Duration: 3 Jun 20128 Jun 2012


Conference38th IEEE Photovoltaic Specialists Conference, PVSC 2012
Country/TerritoryUnited States
CityAustin, TX

Bibliographical note

See CP-5200-54113 for preprint

NREL Publication Number

  • NREL/CP-5200-56925


  • imaging
  • impurities
  • infrared imaging
  • photoluminescence
  • photovoltaic cells
  • silicon


Dive into the research topics of 'Comparison of Photoluminescence Imaging on Starting Multi-Crystalline Silicon Wafers to Finished Cell Performance'. Together they form a unique fingerprint.

Cite this