Advancing the photoelectric performance of tube PECVD-based tunnel oxide passivating contact silicon solar cells by regulating the activated phosphorus concentration in polysilicon

In the current market, the tube plasma-enhanced chemical vapor deposition (PECVD) has become one of the dominant technologies for the preparation of SiO_x and doped polysilicon layers in tunnel oxide passivating contact (TOPCon) solar cells (SCs). The activated phosphorus concentration in polysilicon layers prepared using tube PECVD significantly influences the optical and electrical properties of TOPCon structures. In this work, we effectively control the activated phosphorus concentration in polysilicon through adjusting PH₃ flow rates and investigate the effects of the activated phosphorus concentration on the photoelectric performance of TOPCon SCs, including sheet resistivity, mobility, crystallinity, and parasitic absorption. Specifically, our results show that optimizing the activated phosphorus concentration leads to relatively high crystallinity, and moderate sheet resistivity, mobility, and parasitic absorption. Consequently, a high activated phosphorus concentration with a PH₃ flow rate of 1200 sccm achieves a balance in optical and electrical performance, yielding a relatively high fill factor and short-circuit current density of TOPCon SCs. Based on these results, the average efficiency of industrial screen-printing n-type TOPCon SC increases by 0.17% compared to the baseline sample for 800 sccm conditions on the production line, providing guidance for achieving high-efficiency TOPCon SCs.