Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210-1340, United States.
ACS Nano. 2013 May 28;7(5):4414-21. doi: 10.1021/nn4009406. Epub 2013 Mar 26.
Graphene's success has shown not only that it is possible to create stable, single-atom-thick sheets from a crystalline solid but that these materials have fundamentally different properties than the parent material. We have synthesized for the first time, millimeter-scale crystals of a hydrogen-terminated germanium multilayered graphane analogue (germanane, GeH) from the topochemical deintercalation of CaGe2. This layered van der Waals solid is analogous to multilayered graphane (CH). The surface layer of GeH only slowly oxidizes in air over the span of 5 months, while the underlying layers are resilient to oxidation based on X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy measurements. The GeH is thermally stable up to 75 °C; however, above this temperature amorphization and dehydrogenation begin to occur. These sheets can be mechanically exfoliated as single and few layers onto SiO2/Si surfaces. This material represents a new class of covalently terminated graphane analogues and has great potential for a wide range of optoelectronic and sensing applications, especially since theory predicts a direct band gap of 1.53 eV and an electron mobility ca. five times higher than that of bulk Ge.
石墨烯的成功不仅表明，从结晶固体中制造出稳定的、单原子厚的薄片是可能的，而且这些材料具有与母体材料根本不同的性质。我们首次通过 CaGe2 的拓扑去插层反应合成了毫米级尺寸的氢化锗多层类石墨烷晶体（锗烷，GeH）。这种层状范德华固体类似于多层石墨烷（CH）。GeH 的表面层在空气中仅在 5 个月的时间内缓慢氧化，而基于 X 射线光电子能谱和傅里叶变换红外光谱测量，其底层对氧化具有弹性。GeH 在高达 75°C 的温度下稳定；然而，在高于该温度时，非晶化和脱氢化开始发生。这些薄片可以机械地剥离成单层和少数层，并转移到 SiO2/Si 表面上。这种材料代表了一类新的共价终止的类石墨烷类似物，具有广泛的光电和传感应用的巨大潜力，特别是因为理论预测其直接带隙为 1.53eV，电子迁移率比体锗高约五倍。
