Ruddlesden-Popper 2D Component to Stabilize γ-CsPbI3 Perovskite Phase for Stable and Efficient Photovoltaics
Ruddlesden-Popper 2D Component to Stabilize γ-CsPbI3 Perovskite Phase for Stable and Efficient Photovoltaics
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Ruddlesden-Popper 2D 组件可稳定 γ-CsPbI3 钙钛矿相，实现稳定高效的光伏发电
DOI：
10.1002/aenm.201902529
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发表时间：
2019-09-26
影响因子：
27.8
通讯作者：
Liu, Shengzhong (Frank)
中科院分区：
文献类型：
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作者：
Wang, Kang;Li, Zhizai;Liu, Shengzhong (Frank)
黑相基CsPbI 3钙钛矿太阳能电池的最高认证功率转换效率（PCE）已超过18%，成为近年来研究的热点。然而，由于CsPbI 3的热力学不稳定性，其黑色相在环境条件下迅速转变为黄色相。在此，Ruddlesden-Popper二维结构被引入到γ-CsPbI 3薄膜中，以通过降低维数来稳定黑相。结果表明，适量的碘化苯乙胺可以使γ-CsPbI_3薄膜的尺寸从2D向准2D和3D方向调整。综合考虑获得稳定性和高PCE，准2D（n = 40）γ-CsPbI 3提供了13.65%的可重现PCE，滞后可忽略不计。通过利用飞秒瞬态吸收和时间分辨PL衰减，在n = 40和无穷大的样品中观察到类似的载流子动力学，这意味着有效的电荷提取。更重要的是，当该装置在80 ° C下在N-2条件下或在相对湿度为25- 30%的空气中放置时，其PCE在12天后分别保持其初始PCE的约88%和约89%。这样的结果优于3D的结果（分别为约69%和约16%）。
The highest certified power conversion efficiency (PCE) of black phase based CsPbI3 perovskite solar cells has exceeded 18%, and become a hotspot in recent progress. However, the black phase of CsPbI3 rapidly transforms to yellow phase in ambient conditions due to its thermodynamic instability. Here, a Ruddlesden-Popper 2D structure is introduced into gamma-CsPbI3 film to stabilize the black phase via reducing dimensionality. It is found that a judicious amount of phenylethylammonium iodide can adjust the dimensionality of gamma-CsPbI3 film from 2D to quasi-2D and 3D phase. Comprehensive consideration to obtain both the stability and high PCE, quasi-2D (n = 40) gamma-CsPbI3 delivers a reproducible PCE of 13.65% with negligible hysteresis. By utilizing femtosecond transient absorption and time-resolved PL decay, similar carrier kinetics in n = 40 and infinity samples are observed, meaning an efficient charge extraction. More importantly, when the device is placed at 80 degrees C in N-2 condition or in air with RH of 25-30%, its PCE keeps approximate to 88% and approximate to 89% of its initial PCE after 12 days, respectively. Such results are better than the 3D one (approximate to 69% and approximate to 16%, respectively).