Tunable Chemical Coupling in Two-Dimensional van der Waals Electrostatic Heterostructures
Tunable Chemical Coupling in Two-Dimensional van der Waals Electrostatic Heterostructures
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DOI：
10.1021/acsnano.9b04256
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发表时间：
2019-10-01
期刊：
影响因子：
17.1
通讯作者：
Osada, Minoru
中科院分区：
文献类型：
--
作者：
Taniguchi, Takaaki;Li, Shisheng;Osada, Minoru
二维（2D）原子晶体的异质结构为新兴的物理现象和功能材料提供了迷人的分子尺度设计元素，因为将不同的单层集成到垂直异质结构中可以提供不同性质之间的耦合。然而，可用的例子已被限制到货车的德瓦耳斯（vdW）或静电（ES）异质结构，仅由不带电和带电的单层，分别。在这里，我们提出了一个“vdW-ES异质结构”的化学设计，其中电荷中性和带电的单分子层结构单元具有高度不同的化学和物理性质的共轭垂直通过不对称的带电界面。我们证明了VDW-ES异质组装的半导体二硫化钼和介电Ca 2Nb 3 O 10-（CNO）单层使用两亲性分子淀粉，导致在最低的能量在二硫化钼相关材料中观察到的trion发光的出现，这可能是由于界面限制效应由VDW-ES双重相互作用。此外，由于明显的介电邻近效应，界面工程导致vdW/ES异质结构的定制激子，从而带来了有趣的层间化学来修饰2D材料。此外，目前的方法被成功地扩展到创建石墨烯/CNO异质结构，这验证了制备方法的通用性。
Heterostructures of two-dimensional (2D) atomic crystals provide fascinating molecular-scale design elements for emergent physical phenomena and functional materials, as integrating distinct monolayers into vertical heterostructures can afford coupling between disparate properties. However, the available examples have been limited to either van der Waals (vdW) or electrostatic (ES) heterostructures that are solely composed of noncharged and charged monolayers, respectively. Here, we propose a "vdW-ES heterostructure" chemical design in which charge-neutral and charged monolayer-building blocks with highly disparate chemical and physical properties are conjugated vertically through asymmetrically charged interfaces. We demonstrate vdW-ES heteroassembly of semiconducting MoS2 and dielectric Ca2Nb3O10- (CNO) monolayers using an amphipathic molecular starch, resulting in the emergence of trion luminescence observed at the lowest energy among MoS2-related materials, probably due to interfacial confinement effects given by vdW-ES dual interactions. In addition, interface engineering leads to tailored exciton of the vdW/ES heterostructures owing to the pronounced dielectric proximity effects, bringing an intriguing interlayer chemistry to modify 2D materials. Furthermore, the current approach was successfully extended to create a graphene/CNO heterostructure, which verifies the versatility of the preparative method.