Detecting dopant diffusion enhancement at grain boundaries in multicrystalline silicon wafers with microphotoluminescence spectroscopy

Hieu T. Nguyen, Sudha Mokkapati, Daniel Macdonald

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5 Citations (Scopus)


Employing microphotoluminescence spectroscopy at low temperatures, we are able to detect dopant diffusion enhancement along various grain boundaries and subgrain boundaries in multicrystalline silicon wafers. We find an enhancement of phosphorus diffusion at all investigated grain boundary types. In addition, the subgrain boundaries are demonstrated to contain a relatively high density of defects and impurities, suggesting that their presence does not significantly hinder the preferential diffusion of dopant atoms along the subgrain boundaries. Finally, we demonstrate that the technique can be applied to different diffused layers for solar cell applications, even at room temperature if an appropriate excitation wavelength is used. The results are validated with secondary electron dopant contrast images, which confirm the higher dopant concentration along the grain boundaries and subgrain boundaries.

Original languageEnglish
Article number7828143
Pages (from-to)598-603
Number of pages6
JournalIEEE Journal of Photovoltaics
Issue number2
Publication statusPublished - 20 Jan 2017
Externally publishedYes


  • Crystalline silicon
  • diffusion processes
  • grain boundaries (GBs)
  • photoluminescence
  • photovoltaic cells

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