Efficient ambient-air-stable solar cells with 2D-3D heterostructured butylammonium-caesium-formamidinium lead halide perovskites
Efficient ambient-air-stable solar cells with 2D-3D heterostructured butylammonium-caesium-formamidinium lead halide perovskites
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DOI：
10.1038/nenergy.2017.135
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发表时间：
2017-09-01
期刊：
影响因子：
56.7
通讯作者：
Snaith, Henry J.
中科院分区：
文献类型：
--
作者：
Wang, Zhiping;Lin, Qianqian;Snaith, Henry J.
钙钛矿太阳能电池非常高效；然而，它们在水、氧气和紫外线下很容易降解。 3D 钙钛矿吸收剂中的阳离子工程减少了降解。另外，2D Ruddlesden-Popper 层状钙钛矿表现出更高的稳定性，但迄今为止尚未提供高效的太阳能电池。在这里，我们将正丁基铵阳离子引入混合阳离子铅混合卤化物 FA(0.83)Cs(0.17)Pb(IyBr1-y)(3) 3D 钙钛矿中。我们观察到散布在高度定向的 3D 钙钛矿晶粒之间的 2D 钙钛矿片晶的形成，这抑制了非辐射电荷复合。我们研究了薄膜成分、晶体排列和器件性能之间的关系。具有最佳丁基铵含量的太阳能电池在带隙为 1.61 eV 的钙钛矿中表现出 17.5 +/- 1.3% 的平均稳定功率转换效率，在带隙为 1.72 eV 的钙钛矿中表现出 15.8 +/- 0.8% 的平均稳定功率转换效率。模拟阳光下的稳定性也得到增强。电池在空气中放置 1,000 小时后，可维持 80% 的“老化后”效率，而在封装时则接近 4,000 小时。
Perovskite solar cells are remarkably efficient; however, they are prone to degradation in water, oxygen and ultraviolet light. Cation engineering in 3D perovskite absorbers has led to reduced degradation. Alternatively, 2D Ruddlesden-Popper layered perovskites exhibit improved stability, but have not delivered efficient solar cells so far. Here, we introduce n-butylammonium cations into a mixed-cation lead mixed-halide FA(0.83)Cs(0.17)Pb(IyBr1-y)(3) 3D perovskite. We observe the formation of 2D perovskite platelets, interspersed between highly orientated 3D perovskite grains, which suppress non-radiative charge recombination. We investigate the relationship between thin-film composition, crystal alignment and device performance. Solar cells with an optimal butylammonium content exhibit average stabilized power conversion efficiency of 17.5 +/- 1.3% with a 1.61-eV-bandgap perovskite and 15.8 +/- 0.8% with a 1.72-eV-bandgap perovskite. The stability under simulated sunlight is also enhanced. Cells sustain 80% of their 'post burn-in' efficiency after 1,000 h in air, and close to 4,000 h when encapsulated.