Upgrade-Si-PV – Subproject: Industrially feasible deactivation of the boron-oxygen complex in silicon wafers and solar cells

The phenomenon of light-induced degradation (LID) of solar cells made from boron-doped Czochralski-grown silicon (Cz-Si) has been investigated for many years. It was first shown by ISFH that the root cause for LID in Cz-Si are boron-oxygen-related (BO) defects. Simultaneous illumination and annealing leads to a permanent deactivation of the BO defect centre. So far, the majority of experiments investigating the deactivation was carried out on lifetime test samples, with a few experiments including PERC solar cells. The direct implementation of permanent deactivation into an industrial solar cell process, however, has not been studied in detail yet. This gap will be closed in the present project. The main goal of this project is to test an industrially feasible procedure for the permanent deactivation of the BO complex and to specify the limitations of its application.