Synthetic control over orientational degeneracy of spacer cations enhances solar cell efficiency in two-dimensional perovskites
Synthetic control over orientational degeneracy of spacer cations enhances solar cell efficiency in two-dimensional perovskites
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DOI：
10.1038/s41467-019-08980-x
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发表时间：
2019-03-20
影响因子：
16.6
通讯作者：
You, Wei
中科院分区：
文献类型：
--
作者：
Hu, Jun;Oswald, Iain W. H.;You, Wei
二维钙钛矿已经成为太阳能电池的更内在稳定的材料。间隔基有机阳离子的化学调谐由于其额外的功能性而引起了极大的兴趣。然而，有机阳离子的化学性质如何影响二维钙钛矿和器件的性质却很少报道。在这里，我们证明了间隔阳离子的选择（即，苯乙基铵的选择性氧化）影响二维钙钛矿的膜性质，导致二维钙钛矿太阳能电池的不同器件性能（平均n = 4）。结构分析表明，不同的包装安排和取向无序的间隔阳离子导致取向简并和不同的形成能，在很大程度上解释了薄膜性能的差异。这项工作提供了关键缺失的信息，如何间隔阳离子施加所需的电子性能和二维钙钛矿的器件性能的影响，通过这些阳离子在晶格中的弱和合作的相互作用。
Two-dimensional perovskites have emerged as more intrinsically stable materials for solar cells. Chemical tuning of spacer organic cations has attracted great interest due to their additional functionalities. However, how the chemical nature of the organic cations affects the properties of two-dimensional perovskites and devices is rarely reported. Here we demonstrate that the selection of spacer cations (i.e., selective fluorination of phenethyl-ammonium) affects the film properties of two-dimensional perovskites, leading to different device performance of two-dimensional perovskite solar cells (average n = 4). Structural analysis reveals that different packing arrangements and orientational disorder of the spacer cations result in orientational degeneracy and different formation energies, largely explaining the difference in film properties. This work provides key missing information on how spacer cations exert influence on desirable electronic properties and device performance of twodimensional perovskites via the weak and cooperative interactions of these cations in the crystal lattice.