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层状钙钛矿异质结构单晶的定向组装
作者:小柯机器人 发布时间:2021/9/18 13:58:58

美国斯坦福大学Karunadasa, Hemamala I.团队报道了层状钙钛矿异质结构单晶的定向组装。相关研究成果于2021年9月15日发表在国际顶尖学术期刊《自然》。

不同二维(2D)结构(如石墨烯和MoS2)的精确堆叠为2D材料领域注入了活力,揭示了其界面上的奇异现象。这些独特的界面通常采用机械或基于沉积的方法来构建异质结构,每次构建一个单层。相比之下,自组装是一种可扩展的技术,复杂材料可以在溶液中选择性形成。

该文中,研究人员展示了一种在水溶液中将层状钙钛矿-非钙钛矿异质结构自组装成大单晶的合成策略。利用双功能有机分子作为导向基团,研究人员分离出了六层异质结构,这些异质结构是由钙钛矿板与不同的无机晶格交错而成的,以前不知道会与钙钛矿结晶。在许多情况下,这些共生晶格是典型无机结构类型的2D同系物。据研究人员所知,这些化合物是使用有机模板形成的第一个钙钛矿异质结构,并通过单晶X射线衍射进行了表征。

值得注意的是,该无机结构的交错可以显著地改变带结构。光学数据和第一性原理计算表明,钙钛矿和共生层之间的实质性耦合导致新的电子跃迁分布在两个子晶格上。

鉴于卤化物PrOVSKITES4的技术前景,该直观的合成路线为定向合成水下自组装的富结构复杂半导体奠定了基础。

附:英文原文

Title: Directed assembly of layered perovskite heterostructures as single crystals

Author: Aubrey, Michael L., Saldivar Valdes, Abraham, Filip, Marina R., Connor, Bridget A., Lindquist, Kurt P., Neaton, Jeffrey B., Karunadasa, Hemamala I.

Issue&Volume: 2021-09-15

Abstract: The precise stacking of different two-dimensional (2D) structures such as graphene and MoS2 has reinvigorated the field of 2D materials, revealing exotic phenomena at their interfaces1,2. These unique interfaces are typically constructed using mechanical or deposition-based methods to build a heterostructure one monolayer at a time2,3. By contrast, self-assembly is a scalable technique, where complex materials can selectively form in solution4,5,6. Here we show a synthetic strategy for the self-assembly of layered perovskite–non-perovskite heterostructures into large single crystals in aqueous solution. Using bifunctional organic molecules as directing groups, we have isolated six layered heterostructures that form as an interleaving of perovskite slabs with a different inorganic lattice, previously unknown to crystallize with perovskites. In many cases, these intergrown lattices are 2D congeners of canonical inorganic structure types. To our knowledge, these compounds are the first layered perovskite heterostructures formed using organic templates and characterized by single-crystal X-ray diffraction. Notably, this interleaving of inorganic structures can markedly transform the band structure. Optical data and first principles calculations show that substantive coupling between perovskite and intergrowth layers leads to new electronic transitions distributed across both sublattices. Given the technological promise of halide perovskites4, this intuitive synthetic route sets a foundation for the directed synthesis of richly structured complex semiconductors that self-assemble in water.

DOI: 10.1038/s41586-021-03810-x

Source: https://www.nature.com/articles/s41586-021-03810-x

期刊信息

Nature:《自然》,创刊于1869年。隶属于施普林格·自然出版集团,最新IF:42.778
官方网址:http://www.nature.com/