Stability-limiting heterointerfaces of perovskite photovoltaics
Stability-limiting heterointerfaces of perovskite photovoltaics
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DOI：
10.1038/s41586-022-04604-5
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发表时间：
2022-03-15
期刊：
影响因子：
64.8
通讯作者：
Yang, Yang
中科院分区：
文献类型：
--
作者：
Tan, Shaun;Huang, Tianyi;Yang, Yang
光电器件由不同半导体材料之间形成的异质界面组成。接触半导体之间的相对能级对准决定性地影响异质界面电荷注入和提取动力学。对于钙钛矿太阳能电池（PSC），顶部钙钛矿表面和电荷传输材料之间的异质界面通常被处理用于缺陷钝化（1-4）以改善PSC稳定性和性能。然而，这样的表面处理也会影响异质界面能量（1）。在这里，我们表明，表面处理可能会引起负功函数的变化（即，更多的n型），激活卤化物迁移加剧PSC不稳定。因此，尽管表面钝化的有益效果，但这种有害的副作用限制了以这种方式处理的PSC可获得的最大稳定性改善。这种有利和不利影响之间的权衡应指导通过表面处理改善PSC稳定性的进一步工作。
Optoelectronic devices consist of heterointerfaces formed between dissimilar semiconducting materials. The relative energy-level alignment between contacting semiconductors determinately affects the heterointerface charge injection and extraction dynamics. For perovskite solar cells (PSCs), the heterointerface between the top perovskite surface and a charge-transporting material is often treated for defect passivation(1-4) to improve the PSC stability and performance. However, such surface treatments can also affect the heterointerface energetics(1). Here we show that surface treatments may induce a negative work function shift (that is, more n-type), which activates halide migration to aggravate PSC instability. Therefore, despite the beneficial effects of surface passivation, this detrimental side effect limits the maximum stability improvement attainable for PSCs treated in this way. This trade-off between the beneficial and detrimental effects should guide further work on improving PSC stability via surface treatments.