Detection limits for glow discharge mass spectrometry (GDMS) analyses of impurities in solar cell silicon

• High resolution glow discharge mass spectrometer (GDMS) has been used.
• Detection limits of several elements in solar cell silicon have been investigated.
• The detection limits are approximately 1 ppba or below, except for B, Al, P and Ca.
• All concentrations reported are quantitative.
• Minimum sample preparation and short analysis time have been required.

The measurement of both doping elements and trace elements in solar cell silicon plays a key role for achieving high conversion efficiency of the solar cell device. Doping element concentrations in the range of few hundreds part per billions (ppb) and trace elements in the ppb or sub-ppb concentration range are typically present in multicrystalline silicon wafers for solar cells. Accurate and reliable measurements of these small amounts are not straightforward. The present work describes a fast-flow direct-current high resolution glow discharge mass spectrometer (GDMS). Detection limits for a number of impurities (B, Al, P, Ca, Ti, V, Cr, Mn, Fe, Ni, Co, Cu, Mo, Sn, W and Pb) of interest for solar cell applications have been investigated by GDMS. These detection limits are approximately 1 ppba or below, except for B, Al, P, Ca and Pb. All concentrations reported are quantitative since calculated relative sensitivity factors (RSF‘s) for Si matrix have been used. The detection limits have been achieved with minimum sample preparation and short analysis time.