Determination of relative sensitivity factors for trace element analysis of solar cell silicon by fast-flow glow discharge mass spectrometry

A commercially available Element GD, the latest generation of glow discharge mass spectrometry (GDMS), has been used for quantitative analysis of impurities in silicon for photovoltaic applications (PV silicon). In order to be able to accurately measure impurities in silicon, relative sensitivity factors (RSFs) need to be determined. These factors are, currently, given only for steel matrices. In this study, standard silicon materials with known levels of impurities have been produced and independent analytical methods have been used for determining the RSFs for silicon matrices. It has been found that the tuning parameters of the Element GD, mainly the discharge gas flow rate, influence the RSF values. In addition, it has been found that RSF values are matrix specific; RSFs for a silicon matrix differ significantly from those for metallic conductor matrices even under identical instrumental parameters. A study of the relative reproducibility in the quantitative analysis of impurities in solar cells silicon has shown variations between 5% and 12%.