Highly Distorted Chiral Two-Dimensional Tin Iodide Perovskites for Spin Polarized Charge Transport
Highly Distorted Chiral Two-Dimensional Tin Iodide Perovskites for Spin Polarized Charge Transport
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DOI：
10.1021/jacs.0c03899
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发表时间：
2020-07-29
影响因子：
15
通讯作者：
Beard, Matthew C.
中科院分区：
文献类型：
--
作者：
Lu, Haipeng;Xiao, Chuanxiao;Beard, Matthew C.
将手性有机分子转化为有机/无机杂化2D金属卤化物钙钛矿导致具有独特自旋相关性质的新型手性杂化半导体家族。嵌入的手性有机部分诱导从无机金属卤化物亚晶格的手性光学响应。然而，手性有机分子和无机亚晶格之间的结构相互作用，以及它们对所产生的电子能带结构的协同效应需要在更广泛的材料范围内进行探索。在这里，我们提出了三个新的层状碘化锡钙钛矿模板的手性（R/S-）甲基苄基铵（R/S-MBA），即，(R-/S-MBA）（2）SnI 4和它们的外消旋相（rac-MBA）（2）SnI 4。与任何其他报道的层状碘化锡钙钛矿相比，这些MBA（2）SnI（4）化合物表现出最大水平的八面体键畸变。手性MBA阳离子的掺入导致无机Sn-I亚晶格的圆偏振吸收，在300-500 nm波长范围内显示出手旋光活性。的带隙和手性光活性调制合金锡与铅，在（MBA）Pb 1-xSnxI 4系列。最后，我们表明，通过取向（R-/S-MBA）（2）SnI 4薄膜的垂直电荷输运是高度自旋相关的，来自于手性诱导的自旋选择性（CISS）效应。我们证明了自旋极化的电流-电压特性高达94%。我们的工作显示了这些手性混合半导体控制自旋和电荷自由度的巨大潜力。
Incorporating chiral organic molecules into organic/inorganic hybrid 2D metal-halide perovskites results in a novel family of chiral hybrid semiconductors with unique spin-dependent properties. The embedded chiral organic moieties induce a chiroptical response from the inorganic metal-halide sublattice. However, the structural interplay between the chiral organic molecules and the inorganic sublattice, as well as their synergic effect on the resulting electronic band structure need to be explored in a broader material scope. Here we present three new layered tin iodide perovskites templated by chiral (R/S-)methylbenzylammonium (R/S-MBA), i.e., (R-/S-MBA)(2)SnI4, and their racemic phase (rac-MBA)(2)SnI4. These MBA(2)SnI(4) compounds exhibit the largest level of octahedral bond distortion compared to any other reported layered tin iodide perovskite. The incorporation of chiral MBA cations leads to circularly polarized absorption from the inorganic Sn-I sublattice, displaying chiroptical activity in the 300-500 nm wavelength range. The bandgap and chiroptical activity are modulated by alloying Sn with Pb, in the series of (MBA) Pb1-xSnxI4. Finally, we show that vertical charge transport through oriented (R-/S-MBA)(2)SnI4 thin films is highly spin-dependent, arising from a chiral-induced spin selectivity (CISS) effect. We demonstrate a spin-polarization in the current-voltage characteristics as high as 94%. Our work shows the tremendous potential of these chiral hybrid semiconductors for controlling both spin and charge degrees of freedom.