TOPCon太阳电池发射极Al2O3/SiNx与SiO2/Al2O3/SiNx叠层膜钝化性能的比较

本文对TOPCon电池发射结的叠层钝化膜进行了研究,对比了3种不同叠层钝化膜(SiO₂/SiN_x、Al₂O₃(1.5 nm)/SiN_x、SiO₂/Al₂O₃(1.5 nm)/SiN_x)的钝化性能。结果表明:Al₂O₃(1.5 nm)/SiN_x的钝化性能优于SiO₂/SiN_x,SiO₂/Al₂O₃(1.5 nm)/SiN_x的钝化水平最佳,隐开路电压均值可达到705 mV。基于Al₂O₃/SiN_x叠层膜研究了Al₂O₃厚度(1.5 nm、3 nm和5 nm)对钝化性能和电池转换效率的影响。当Al₂O₃厚度由1.5 nm增加到3 nm时,钝化性能得到明显提升,隐开路电压均值提高了20 mV,达到707 mV,对应电池的光电转换效率升高了0.23个百分点,与SiO₂/Al₂O₃(1.5 nm)/SiN_x叠层膜电池的转换效率持平。然而,当Al₂O₃厚度继续增加至5 nm时,隐开路电压均值保持不变。因此可以使用Al₂O₃(3 nm)/SiN_x叠层膜代替SiO₂/Al₂O₃(1.5 nm)/SiN_x叠层膜,不仅简化了电池的工艺步骤,而且降低了生产成本。

Comparative Study on Passivation Performance of Al2O3/SiNx and SiO2/Al2O3/SiNx Stacked Films for Emitter of TOPCon Solar Cells

The stacked passivation films for emitter of TOPCon solar cells were investigated in the paper. The passivation performance of three different stacked films (SiO₂/SiN_x, Al₂O₃(1.5 nm)/SiN_x, SiO₂/Al₂O₃(1.5 nm)/SiN_x) were compared. The results show that the Al₂O₃ (1.5 nm)/SiN_x films exhibit better passivation performance than that of the SiO₂/SiN_x films, and the SiO₂/Al₂O₃(1.5 nm)/SiN_x films perform the best, with an implied open circuit voltage of 705 mV. Based on the Al₂O₃/SiN_x stacked passivation films, the effect of Al₂O₃ thickness (1.5 nm, 3 nm and 5 nm) on the passivation performance and photoelectric conversion efficiency of cells were investigated. When the thickness of Al₂O₃ increases from 1.5 nm to 3 nm, the passivation performance is significantly improved, the mean value of the implied open circuit voltage increases by 20 mV to 707 mV, and the conversion efficiency of the corresponding cells increases by 0.23 percentage point, which is comparable to that of the SiO₂/Al₂O₃(1.5 nm)/SiN_x stacked films cells. However, when the thickness of Al₂O₃ continues to increase to 5 nm, the mean value of the implied open circuit voltage remains unchanged. Therefore, Al₂O₃(3 nm)/SiN_x stacked films can be used to replace the SiO₂/Al₂O₃(1.5 nm)/SiN_x stacked films, which not only simplifies the process flow of the solar cells, but also reduces the production cost.