Low-Temperature Saw Damage Gettering to Improve Minority Carrier Lifetime in Multicrystalline Silicon
Low-Temperature Saw Damage Gettering to Improve Minority Carrier Lifetime in Multicrystalline Silicon
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低温锯损伤吸杂可提高多晶硅中少数载流子的寿命
DOI：
10.1002/pssr.201700268
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
Al-Amin M
中科院分区：
文献类型：
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作者：
Al-Amin M
多晶硅是当今制造的大多数太阳能电池中使用的材料，其少数载流子寿命受到材料内部缺陷的限制，包括在低温（≤700 °C）下相对移动的金属杂质。添加可促进杂质扩散到晶片表面处的锯损伤的优化的热工艺可导致在锯损伤被蚀刻掉时杂质的永久去除。我们证明了这种锯损伤吸除在500至700 °C下是有效的，并且当与随后的低温处理相结合时，相对于生长状态，寿命提高了四倍以上。这种简单的方法有可能成为一种低热预算工艺，用于改善低寿命“红区”晶片。
The minority carrier lifetime in multicrystalline silicon − a material used in the majority of today's manufactured solar cells − is limited by defects within the material, including metallic impurities which are relatively mobile at low temperatures (≤700 °C). Addition of an optimised thermal process which can facilitate impurity diffusion to the saw damage at the wafer surfaces can result in permanent removal of the impurities when the saw damage is etched away. We demonstrate that this saw damage gettering is effective at 500 to 700 °C and, when combined with subsequent low‐temperature processing, lifetimes are improved by a factor of more than four relative to the as‐grown state. The simple method has the potential to be a low thermal budget process for the improvement of low‐lifetime “red zone” wafers.