Perovskite solar cells with atomically coherent interlayers on SnO2 electrodes
Perovskite solar cells with atomically coherent interlayers on SnO2 electrodes
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DOI：
10.1038/s41586-021-03964-8
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发表时间：
2021-10-21
期刊：
影响因子：
64.8
通讯作者：
Seok, Sang Il
中科院分区：
文献类型：
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作者：
Min, Hanul;Lee, Do Yoon;Seok, Sang Il
在钙钛矿太阳能电池中，钙钛矿和电荷传输层之间的界面含有高浓度的缺陷（约为钙钛矿层内的100倍），具体地，深能级缺陷，其显著降低了器件（1-3）的功率转换效率。最近减少这些界面缺陷的努力主要集中在表面钝化上（4-6）。然而，钝化与电子传输层界面的钙钛矿表面是困难的，因为在涂覆钙钛矿薄膜时，电子传输层上的表面处理剂可能溶解。或者，如果在电子传输层和钙钛矿层之间可以形成共格界面，则界面缺陷可以不是问题。在这里，我们报告之间的SnO 2电子传输层和卤化物钙钛矿光吸收层，通过耦合Cl键合的SnO 2与含Cl的钙钛矿前体实现的夹层的形成。该中间层具有原子相干特征，其增强了从钙钛矿层的电荷提取和传输，以及较少的界面缺陷。这种连贯夹层的存在使我们能够制造出在标准照明下功率转换效率为25.8%（认证为25.5%）的钙钛矿太阳能电池。此外，未封装的器件即使在连续曝光500小时后仍保持约90%的初始效率。我们的发现为设计金属卤化物钙钛矿和电子传输层之间的缺陷最小化界面提供了指导。钙钛矿太阳能电池中电子传输层和钙钛矿层之间的原子相干夹层增强了钙钛矿的电荷提取和传输，从而实现了高功率转换效率。
In perovskite solar cells, the interfaces between the perovskite and charge-transporting layers contain high concentrations of defects (about 100 times that within the perovskite layer), specifically, deep-level defects, which substantially reduce the power conversion efficiency of the devices(1-3). Recent efforts to reduce these interfacial defects have focused mainly on surface passivation(4-6). However, passivating the perovskite surface that interfaces with the electron-transporting layer is difficult, because the surface-treatment agents on the electron-transporting layer may dissolve while coating the perovskite thin film. Alternatively, interfacial defects may not be a concern if a coherent interface could be formed between the electron-transporting and perovskite layers. Here we report the formation of an interlayer between a SnO2 electron-transporting layer and a halide perovskite light-absorbing layer, achieved by coupling Cl-bonded SnO2 with a Cl-containing perovskite precursor. This interlayer has atomically coherent features, which enhance charge extraction and transport from the perovskite layer, and fewer interfacial defects. The existence of such a coherent interlayer allowed us to fabricate perovskite solar cells with a power conversion efficiency of 25.8 per cent (certified 25.5 per cent)under standard illumination. Furthermore, unencapsulated devices maintained about 90 per cent of their initial efficiency even after continuous light exposure for 500 hours. Our findings provide guidelines for designing defect-minimizing interfaces between metal halide perovskites and electron-transporting layers.An atomically coherent interlayer between the electron-transporting and perovskite layers in perovskite solar cells enhances charge extraction and transport from the perovskite, enabling high power conversion efficiency.