缺陷辅助隧穿对TOPCon太阳能电池性能的影响

The Effect of Trap-Assisted Tunneling on the Performance of TOPCon Solar Cells

TOPCon太阳能电池超薄氧化硅层中的载流子的直接隧穿和针孔传输是两种当前被广泛探讨的机制,在实际电池制造过程中,超薄氧化硅层在高温诱导应力下在产生针孔的同时,也可能伴随大量缺陷的出现,这些缺陷有助于载流子通过缺陷辅助隧穿进行传输。本文通过数值求解漂移扩散输运方程,理论模拟了光照下TOPCon太阳能电池的性能在氧化层厚度为2.0 nm的情况下,综合考虑直接隧穿和缺陷辅助隧穿作为两种主要的输运机制,TOPCon太阳能电池效率将会提高。研究了电池填充因子随氧化层电子有效质量的依赖关系。接着讨论了从晶体硅体寿命和背面多晶硅浓度对TOPCon太阳能电池性能的影响。本文的研究结果不仅有助于加深人们对TOPCon太阳能电池载流子输运机制的理解,还为优化电池结构设计提供了有益的理论指导。

The direct tunneling and pinhole transport of charge carriers in the ultra-thin silicon oxide layer of TOPCon solar cells are two widely discussed mechanisms. In the actual solar cell manufacturing process, the ultra-thin silicon oxide layer may generate pinholes under high-temperature induced stress, which may also be accompanied by a large number of traps. These traps help transport charge carriers through trap-assisted tunneling. This article numerically solves the drift diffusion transport equation and theoretically simulates the performance of TOPCon solar cells under illumination. With an oxide layer thickness of 2.0 nm, considering direct tunneling and trap-assisted tunneling as the two main transport mechanisms, the efficiency of TOPCon solar cells will be improved. The dependence of filling factor on the effective mass of oxide layer electrons was studied. Subsequently, the effects of crystal silicon lifetime and impurity concentration in the backside polycrystalline silicon on the performance of TOPCon solar cells were discussed. The research results presented in this paper not only deepen our understanding of the carrier transport mechanisms in TOPCon solar cells but also provide valuable theoretical guidance for optimizing the design of cell structures.