Impact of heat‐light soaking and heat‐bias soaking on NaF‐treated CIGS thin film solar cells
Impact of heat‐light soaking and heat‐bias soaking on NaF‐treated CIGS thin film solar cells
复制标题
热光均热和热偏热均热对 NaF 处理的 CIGS 薄膜太阳能电池的影响
DOI：
10.1002/pip.3135
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
T. Nakada
中科院分区：
文献类型：
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作者：
Junpei Matsuura;I. Khatri;Tzu‐Ying Lin;M. Sugiyama;T. Nakada
研究了热光浸泡（HLS）和热偏压浸泡（HBS）对NaF处理的Cu（In，Ga）Se2（CIGS）太阳电池的影响。HLS提高了NaF处理的CIGS太阳能电池的电池效率，增加了开路电压（VOC），而短路电流密度（JSC）略有下降。降低的JSC是由于HLS导致的显著高的载流子浓度引起的，从而导致相当窄的空间电荷区域。然而，通过随后在黑暗中的适度热浸泡（HS），可以成功地恢复还原的JSC，从而提高电池效率。另一方面，没有观察到无NaF太阳能电池的有益效果。二次离子质谱（西姆斯）的测量结果表明，Na和K离子的增加，特别是在CIGS表面区域附近的HLS过程后。这一结果表明，这些离子被光致电场移动。热活化和电活化的碱金属离子可以消除CIGS吸收剂中的施主样缺陷，导致受体浓度增加。此外，我们发现，一个外部正向偏压没有光照射（HBS）导致了同样的效果HLS。基于这些结果，提出了NaF处理的CIGS太阳能电池的HLS和HBS效应的可能机制。
The effects of heat‐light soaking (HLS) and heat‐bias soaking (HBS) were investigated on NaF‐treated Cu (In,Ga)Se2 (CIGS) solar cells. The HLS improved the cell efficiency with increased open‐circuit voltage (VOC) for NaF‐treated CIGS solar cells, whereas the short‐circuit current density (JSC) slightly decreased. The reduced JSC was caused by the significantly high carrier concentration due to the HLS, leading to a fairly narrow space charge region. However, the reduced JSC could be successfully recovered by the subsequent moderate heat soaking (HS) in the dark, thereby improving cell efficiency. On the other hand, no beneficial effect was observed for NaF‐free solar cells. Secondary ion mass spectrometry (SIMS) measurements revealed that the Na and K ions increased especially near the CIGS surface region after the HLS process. This result suggests that these ions were shifted by the photo‐induced electric field. The thermally and electrically activated alkali ions may eliminate the donor‐like defects in CIGS absorber, resulting in an increased acceptor concentration. Furthermore, we found that an external forward bias without light irradiation (HBS) resulted in the same effect as HLS. Based on these results, a possible mechanism of HLS and HBS effects was proposed on NaF‐treated CIGS solar cells.