Effects of X-rays on Perovskite Solar Cells
Effects of X-rays on Perovskite Solar Cells
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DOI：
10.1021/acs.jpcc.0c04645
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发表时间：
2020-08-20
影响因子：
3.7
通讯作者：
Bertoni, Mariana, I
中科院分区：
文献类型：
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作者：
Stuckelberger, Michael E.;Nietzold, Tara;Bertoni, Mariana, I
同步辐射微纳探测光束线在发展光伏器件方面显示出巨大的潜力。最重要的是，它们的小X射线光斑尺寸使各种多晶太阳能电池的电性能与亚颗粒分辨率的元素组成直接相关。虽然大多数无机半导体在聚焦X射线束的高X射线通量下是稳定的，但含有有机成分的半导体容易发生各种退化机制。这对于评估新兴的有机金属卤化物钙钛矿太阳能电池尤为关键。在这里，我们研究了硬X射线对这些太阳能电池的纳米级性能和元素分布的影响。我们表明，它们的组成在普通的操纵腔和同步加速器纳米探针的原位测量中没有改变。然而，我们发现带有甲基碘化铅吸收剂的太阳能电池在X射线诱导下发生了显著的电子退化。与时间和剂量相关的测量揭示了两个特征退化时间常数，其量级分别为12和200 S，它们与X射线通量无关。在热和剂量模拟的基础上，我们将快速衰变归因于剂量驱动的复合中心的产生，而慢衰变与观察到的成分变化相一致。最后，我们详细说明了退化引起的测量伪影如何能够超越，并展示了X射线束感应电流与碘和铅分布的高度相关性。
Synchrotron micro- and nanoprobe beamlines have demonstrated great potential to advance photovoltaic devices. Most importantly, their small X-ray spot size has enabled the direct correlation of electrical performance with elemental composition at subgrain resolution for a variety of polycrystalline solar cells. Whereas the bulk of most inorganic semiconductors is stable under the high X-ray flux of focused X-ray beams, semiconductors with organic components are prone to a variety of degradation mechanisms. This is particularly critical to evaluate for the emerging organometal halide perovskite solar cells. Here, we investigate the effects of hard X-rays on the nanoscale performance and elemental distribution of these solar cells. We show that their composition does not change during common operando and in situ measurements at synchrotron nanoprobes. However, we found a significant X-ray-induced electronic degradation of solar cells with methylammonium lead iodide absorbers. Time- and dose-dependent measurements unveiled two characteristic degradation time constants on the order of 12 and 200 s that are independent of the X-ray flux. On the basis of heat and dose simulations, we attribute the fast decay to the dose-driven creation of recombination centers, while the slow decay is compatible with the observation of compositional changes. Finally, we detail how degradation-induced measurement artifacts can be outrun and showcase the high correlation of the X-ray-beam-induced current with the iodine and lead distribution.