【摘要】 低维Bi2Se3纳米材料是最新研究发现的一种新型三维拓扑绝缘体材料,在微电子器件和传感器领域具有广阔的应用前景。本研究采用气相传输法在真空石英管中合成了大尺寸单晶Bi2Se3纳米片、纳米带。通过XRD、EDS、Raman、SEM等手段对Bi2Se3纳米片、纳米带的物相结构、组成、表面形貌等进行表征。测试结果表明:气相传输法合成的单晶Bi2Se3纳米片、纳米带相纯度高,结晶性能好,均是{001}取向;Bi2Se3纳米片水平尺寸大,约为15~180μm;Bi2Se3纳米带长度达860μm,宽度约5μm。根据不同温度下制备的Bi2Se3纳米片、纳米带SEM照片及其不同方向结合能的差异,分析了其可能的生长机制:在较高温度下沿<001>和<1010>方向生长速度快,生成大尺寸单晶Bi2Se3纳米片;在较低温度下,沿<1120>方向生长速度快,生成大尺寸单晶Bi2Se3纳米带。这些研究结果完善了大尺寸Bi2Se3纳米材料的制备工艺,有望在微电子器件领域得到商业化应用。更多还原

【Abstract】 Low-dimensional Bi2Se3 nanomaterials were discovered to be new three-dimensional(3D) topological insulators(TIs) recently, which have broad application prospect in the field of microelectronic devices and sensors. Single crystalline Bi2Se3 nanoplates(NPs) and nanoribbons(NRs) with jumbo size were synthesized in the vacuum quartz tube via vapor transportation. The crystal structure, composition and morphology of the as-prepared Bi2Se3 NPs and NRs were analyzed by XRD, EDS, Raman and SEM. It is found that both of the two specimens are well-crystallized in the direction of {001} with a high purity. Bi2Se3 NPs have a large lateral size of 15-180 μm, while Bi2Se3 NRs have a large length of 860 μm and a width of about 5 μm. Besides, the probable growth mechanism is proposed based on the analysis of the SEM images of Bi2Se3 NPs and NRs prepared at different temperatures and the binding energy difference along different directions. Bi2Se3 has a quicker growth speed along <001> and <1010 > directions in relatively high temperature to form single crystalline NPs with large lateral size, while it grows faster along <1120 > direction in lower temperature to get single crystalline NRs with large length. All these results not only improve the preparation process of Bi2Se3 nanomaterials with jumbo size, but also promote the commercial use in the field of microelectronic devices.更多还原