Cluster-assembled materials: toward nanomaterials with precise control over properties.
Cluster-assembled materials: toward nanomaterials with precise control over properties.
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DOI：
10.1021/nn9010297
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发表时间：
2010-01
期刊：
影响因子：
17.1
通讯作者：
M. Qian;A. Reber;A. Ugrinov;N. K. Chaki;S. Mandal;H. M. Saavedra;S. Khanna;Ayusman Sen;P. Weiss
中科院分区：
文献类型：
--
作者：
M. Qian;A. Reber;A. Ugrinov;N. K. Chaki;S. Mandal;H. M. Saavedra;S. Khanna;Ayusman Sen;P. Weiss
实现具有可控带隙的纳米材料的一种途径是组装固体，其中原子团簇作为构建块，因为团簇的电子结构随尺寸和组成而变化。为了研究组织在簇组装中的作用，我们合成了多种结构，通过控制抗衡阳离子将As（7）（3-）簇。光学测量显示，带隙从1.1-2.1 eV变化，即使组件是从相同的集群构建块。理论研究将这种变化解释为通过改变抗衡阳离子来改变最低未占分子轨道水平的结果。差距的其他变化是通过共价连接具有不同电负性的物质的簇来改变电荷转移的程度。这些发现提供了一个通用的协议与可调的电子性能的纳米组装体的合成。
One pathway toward nanomaterials with controllable band gaps is to assemble solids where atomic clusters serve as building blocks, since the electronic structures of clusters vary with size and composition. To study the role of organization in cluster assemblies, we synthesized multiple architectures incorporating As(7)(3-) clusters through control of the countercations. Optical measurements revealed that the band gaps vary from 1.1-2.1 eV, even though the assemblies are constructed from the identical cluster building block. Theoretical studies explain this variation as being a result of altering the lowest unoccupied molecular orbital levels by changing the countercations. Additional variations in the gap are made by covalently linking the clusters with species of varying electronegativity to alter the degree of charge transfer. These findings offer a general protocol for syntheses of nanoassemblies with tunable electronic properties.