Multi-Isotopic Analysis for Robust Traceability of Crystalline Silicon Wafers
No Thumbnail Available
Author
Paviet-Salomon, Bertrand
Bérail, Sylvain
Barre, Julien P.G.
Pécheyran, Christophe
DOI
10.1109/PVSC59419.2025.11133388
Abstract
This work investigates tracking methods to authenticate the origin of crystalline silicon (c-Si) wafers used by the PV industry and to identify those from companies using forced labor during fabrication. Along these lines, the 29Si/28Si and the 30Si/28Si isotopic ratios (δ29Si and δ30Si, resp.) in c-Si wafers sourced from seven different suppliers worldwide were analyzed using highly sensitive and highly precise atomic mass spectrometry techniques, namely multi-collector inductively coupled plasma mass spectroscopy (MC-ICPMS) and femtosecond laser ablation ICPMS. The analysis of the sourced cSi wafers revealed a clear, unique (δ30Si, δ29Si) isotopic footprint for each manufacturer, with δ30Si (resp. δ29Si) spanning between ±1.50 ‰ (resp. ±1.00 ‰) and excellent R2 values. Even if the root causes of the isotopic fractionation along the c-Si wafer production stream are still to be evidenced, these results open the way to a robust and unambiguous method to authenticate c-Si wafers. Applications and replications to other c-Si-based devices are foreseen, such as for chips and detectors, where the requests for supply chain transparency and traceability exist as well.
Publication Reference
Conference Record of the IEEE Photovoltaic Specialists Conference, pp. 1086 - 1088
Year
2025