Electrical Properties of Fe‐Contaminated Oxidation‐Induced Stacking Fault in n‐Type Czochralski Silicon

Oxidation‐induced stacking fault (OISF) is one of the important detrimental defects in n‐type tunnel oxide passivated contact (TOPCon) structure silicon solar cells due to its boron diffusion process at elevated temperature. Herein, the electrical properties of Fe‐contaminated OISFs in n‐type silicon are studied by combining electron beam‐induced current (EBIC) and deep‐level transient spectroscopy (DLTS) techniques. The EBIC results confirm that both Frank partial loops and fault planes are effective gettering sites for iron impurities. The DLTS reveals two energy levels of E1 ( E C – 0.43 eV) and E2 ( E C – 0.20 eV). The origin of E1 is attributed to Fe clusters bounded to the Frank partial dislocations, and E2 might be related to intermediate Fe complexes gettered on the fault planes of OISFs. E1 exhibits the donor state by confirming Poole–Frenkel field enhanced emission effect while this effect is not observed for E2. In addition, hydrogenation is proved to be able to partly passivate the electrical activity of the Fe‐contaminated OISFs. The results are instructive for bulk defect engineering toward high‐efficiency n‐type TOPCon solar cells.