Mesostructured germanium with cubic pore symmetry
Mesostructured germanium with cubic pore symmetry
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DOI：
10.1038/nature04833
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发表时间：
2006-06-28
期刊：
影响因子：
64.8
通讯作者：
Kanatzidis, Mercouri G.
中科院分区：
文献类型：
--
作者：
Armatas, Gerasimos S.;Kanatzidis, Mercouri G.
规则介孔氧化物材料已被广泛研究(1-8)，并在催化、吸附和分离等方面具有广泛的潜在应用。人们通常不会考虑它们的光学和电学性质。带有纳米孔的元素半导体代表了一种不同形式的框架材料，其物理特性与更传统的块状、薄膜和纳米晶体形式形成对比(1)。在这里，我们描述了立方介观结构的锗，MSU-Ge-1，含有表面活性剂分子的回转通道，由位于回转(G)最小表面上的无定形壁隔开，如在介孔二氧化硅MCM-48(参考文献.2)。尽管Ge是一种高熔点的共价半导体，很难通过溶液聚合来制备，但我们成功地利用合适的Ge42原子前驱体组装了一个连续的Ge网络。我们的结果表明，元素周期表第14族的元素半导体可以采用介观结构形式，如MSU-Ge-1，其特征是在bard空间群对称性上具有两个服从Ia(3)的三维迷宫隧道，并被一个连续的无定形的Ge最小表面分开。这种新结构的结果是，锗的壁厚只有一纳米，比结晶态或非晶态锗的电子能带隙(1.4 eV比0.66 eV)更宽。MSU-Ge-1的受控氧化产生了一系列具有连续变化的Ge：O比和平稳增加的能隙的Ge亚氧化物。
Regular mesoporous oxide materials have been widely studied(1-8) and have a range of potential applications, such as catalysis, absorption and separation. They are not generally considered for their optical and electronic properties. Elemental semiconductors with nanopores running through them represent a different form of framework material with physical characteristics contrasting with those of the more conventional bulk, thin film and nanocrystalline forms(1). Here we describe cubic mesostructured germanium, MSU-Ge-1, with gyroidal channels containing surfactant molecules, separated by amorphous walls that lie on the gyroid (G) minimal surface as in the mesoporous silica MCM-48 (ref. 2). Although Ge is a high-melting, covalent semiconductor that is difficult to prepare from solution polymerization, we succeeded in assembling a continuous Ge network using a suitable precursor for Ge 42 atoms. Our results indicate that elemental semiconductors from group 14 of the periodic table can be made to adopt mesostructured forms such as MSU-Ge-1, which features two three-dimensional labyrinthine tunnels obeying Ia (3) over bard space group symmetry and separated by a continuous germanium minimal surface that is otherwise amorphous. A consequence of this new structure for germanium, which has walls only one nanometre thick, is a wider electronic energy bandgap (1.4 eV versus 0.66 eV) than has crystalline or amorphous Ge. Controlled oxidation of MSU-Ge-1 creates a range of germanium suboxides with continuously varying Ge:O ratio and a smoothly increasing energy gap.