Effect of Iron Contamination on the Electrical Properties and Nucleation of Oxygen Precipitates in Ga‐Doped Continuously Czochralski Silicon

Ga‐doped continuously Czochralski silicon (CCz‐Si) is promising for p‐type silicon solar cells due to its superior axial resistivity uniformity, high productivity, and immunity to light‐induced degradation (LID). However, multiple crucibles designing and prolonged operation duration lead to more severe erosion of crucibles, resulting in higher concentration of oxygen and metal impurities (particularly iron). This study elucidates the role of iron contamination in promoting oxygen precipitation and modifying the electrical activity of oxygen precipitates (OPs). By combining electron beam‐induced current (EBIC), deep‐level transient spectroscopy (DLTS), and Fourier‐transform infrared spectroscopy (FTIR), it is demonstrated that iron significantly enhances the nucleation of oxygen precipitates. Critically, we identify an evolutionary pathway where FeGa pairs dissociate upon annealing to form intermediate FeO complexes ( E _v  + 0.33 eV, σ _p  = 3.2 × 10 ⁻¹⁶  cm ⁻² ). These FeO complexes are likely to serve as highly effective heterogeneous nucleation centers, accelerating oxygen precipitation and leading to a higher density of OPs with deeper energy level and increased carrier capture cross section. These findings provide a mechanistic understanding of iron–oxygen‐dopant interactions in Ga‐doped CCz‐Si, offering crucial insights for defect engineering to mitigate the detrimental effects of metal impurities in cost‐effective photovoltaic silicon.