The Causes of Degradation of Perovskite Solar Cells
The Causes of Degradation of Perovskite Solar Cells
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DOI：
10.1021/acs.jpclett.9b00613
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发表时间：
2019-10-03
影响因子：
5.7
通讯作者：
Juarez-Perez, Emilio J.
中科院分区：
文献类型：
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作者：
Bisquert, Juan;Juarez-Perez, Emilio J.
去年，钙钛矿太阳能电池领域达到了两个重要的里程碑，这将使我们更接近这种光收集器材料即将到来的商业用途。其中一个是Saule Technologies的第一个钙钛矿建筑集成光伏（BIPV）产品演示。1另一个重要的里程碑是Oxford PV获得的1平方厘米钙钛矿-硅串联太阳能电池的新认证世界纪录，实现了28%的转换效率，2超过了他们之前在2018年早些时候宣布的27.3%的效率认证纪录。上述第一项成就是与新兴的antomasy染料敏化太阳能电池技术的技术和象征性匹配，该技术也集成在建筑物中用于演示目的。3下一个成就更相关，因为成熟的硅基太阳能电池器件表现出了出色的集成度，而不是串联器件实现的惊人效率记录。考虑到这两个令人鼓舞的检查点，我们从2019年开始对混合钙钛矿的两个最严厉的批评持乐观态度，原则上来自两个不同的方面。首先，设备的预期稳定性如何，其次，但同样重要的是，如何解决铅含量的环境问题。如果用同一个对策来解决这两个问题，岂不是很好？封装是这样的解决方案吗？原则上，钙钛矿太阳能电池在延长的时间间隔内释放最大效率的失败可能是由于光收集器材料和/或用于设备的适当操作的必要组件（例如选择性接触）的劣化。到目前为止所做的大部分工作都集中在理解钙钛矿材料的降解机制上，其中指出，发生的主要过程是混合钙钛矿有机部分的蒸发过程。该过程产生了大部分完整的无机骨架固体残余物，其不再用于光捕获，但是可以通过重新引入有机阳离子来优雅地回收钙钛矿相。因此，为什么封装的设备在长期内经常缓慢地失去效率，直到完全耗尽？在关于“钙钛矿太阳能电池退化的原因”主题的观点集合中，综述了不同的方法来揭示作为太阳能电池中活性材料的混合钙钛矿材料的消失。第一篇观点文章题为“Prospects for Mitigating Intrinsic Organic Decomposition in Methylammonium Lead Triiodide Peroxide”4，作者为McLeod和Liu，总结了对甲基铵基碘化铅钙钛矿（MAPbI 3）内在稳定性的见解。作者专注于所谓的“内在”分解，而不是“外在”分解驱动的外部代理人，如水分和/或氧气。事实上，在没有这些外部试剂的情况下诱导MAPbI 3的热分解可能是理解其分解的最佳方式，正如预期的那样适用于包封的钙钛矿。最新的甲基铵基钙钛矿分解的途径进行了讨论，从X射线光电子和吸收精细结构光谱（XPS和XAFS）和红外光谱（FTIR）测量的输出结果在这个角度来看。特别强调XPS中的C和N 1 s态及其解释成为MAPbI 3可能遵循两种不同途径分解的实验证据
Last year, two important milestones were reached in the field of perovskite solar cells that would bring us closer to imminent commercial use of this light-harvester material. One was the first perovskite-based building integrated photovoltaic (BIPV) product demonstration by Saule Technologies. 1 Another significant landmark was a new certified world record for a 1 cm2 perovskite− silicon tandem solar cell achieving 28% conversion efficiency achieved by Oxford PV, 2 which surpassed their previous certified record of 27.3% efficiency announced earlier during 2018. The first achievement outlined above is a technological and symbolic tied match with the emergent antonomasy dye-sensitized solar cell technology that also became integrated in buildings for demonstration purposes. 3 The next achievement is more relevant due to the excellent integration demonstrated with mature Si-based solar cell devices, even rather than the terrific efficiency record achieved by the tandem device. With these two encouraging checkpoints in mind, we start 2019 optimistic of the two harshest criticisms for hybrid perovskite coming, in principle, from two different fronts. First, what will be the expected stability of the devices, and second, but no less important, how will the environmental problem of the lead content be addressed. Would it not be great if these two problems were solved using the same countermeasure? Is encapsulation such a solution? In principle, the failure of a perovskite solar cell to release maximum efficiency over a prolonged time interval may be due to degradation of the light-harvester material and/or necessary components for proper operation of the device, such as selective contacts. Much of the work done until now focused on the understanding of the mechanism of degradation of the perovskite material, which noted that the main underlining process occurring is an evaporation-like process of the organic part of the hybrid perovskite. The process results in a mostly intact inorganic framework solid residue that is no longer useful for light harvesting, but gracefully, the perovskite phase could be recovered by reincorporating the organic cation. Therefore, why then do encapsulated devices so often slowly lose their efficiency in the long term until total exhaustion? In this collection of perspectives on the topic of “The Causes of Degradation of Perovskite Solar Cells”, different approaches are reviewed to unravel the fade away of the hybrid perovskite material acting as an active material in solar cells. The first perspective article, entitled “Prospects for Mitigating Intrinsic Organic Decomposition in Methylammonium Lead Triiodide Perovskite” 4 and authored by McLeod and Liu, summarizes insights into the intrinsic stability of methylammonium-based lead iodide perovskite (MAPbI3). The authors focus on the so-called “intrinsic” decomposition rather than the “extrinsic” decomposition driven by external agents such as moisture and/or oxygen. In fact, inducing thermal decomposition in MAPbI3 in the absence of these external agents may be the best way to understand its decomposition, as expected to apply for encapsulated perovskite. The most recent pathways for methylammonium-based perovskite decomposition are discussed in this Perspective in light of the output results from X-ray photoelectron and absorption fine structure spectroscopies (XPS and XAFS) and infrared spectroscopy (FTIR) measurements. A special emphasis is made on the C and N 1s states in XPS and their interpretation becoming experimental evidence that MAPbI3 may decompose following two different routes