Nanostructuring Germanium Nanowires by In Situ TEM Ion Irradiation
Nanostructuring Germanium Nanowires by In Situ TEM Ion Irradiation
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DOI：
10.1002/ppsc.202100154
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发表时间：
2021-11-01
影响因子：
2.7
通讯作者：
Hinks，Jonathan A.
中科院分区：
文献类型：
--
作者：
Camara，Osmane;Mir，Anamul H.;Hinks，Jonathan A.
一旦合成了纳米材料，诱导进一步的结构修饰就具有挑战性。然而，能够以可控的方式这样做至关重要。在这种情况下，锗纳米线在透射电子显微镜（TEM）内通过300 keV氙离子束在室温（RT）至500 °C的温度范围内原位照射。在原位进行离子辐照，并监测辐照过程中纳米线的演变。在300 °C及以下，其中温度低到足以允许非晶化，离子束导致纳米线内的纳米结构的形成。在2.2 × 1014和高达4.2 × 1015离子cm-2的极低能量密度下，观察到纳米孔的形成和纳米线的膨胀。在更高的能量密度下，纳米线的厚度减小，纳米线失去其线状圆柱形状，并且由离子束引起的纳米结构化变得更加复杂。当纳米线在530 °C下退火时，观察到纳米结构在结晶时是稳定的。此外，原位成像允许在RT和300 °C下跟踪照射期间纳米孔的生长，从而提供对负责纳米结构化的机制的有价值的见解。
Once nanomaterials have been synthesized, inducing further structural modifications is challenging. However, being able to do so in a controlled manner is crucial. In this context, germanium nanowires are irradiated in situ within a transmission electron microscope (TEM) by a 300 keV xenon ion beam at temperatures ranging from room temperature (RT) to 500 °C. The ion irradiation is performed in situ and the evolution of nanowires during irradiation is monitored. At 300 °C and below, where the temperature is low enough to allow amorphization, the ion beam causes the formation of nanostructures within the nanowires. Formation of nanopores and swelling of nanowires is observed for a very low fluence of 2.2 × 1014and up to 4.2 × 1015ions cm−2. At higher fluences, the thickness of the nanowires decreases, the nanowires lose their wire‐like cylindrical shape and the nanostructuring caused by the ion beam becomes more complex. The nanostructures are observed to be stable upon crystallization when the nanowires are annealed at 530 °C. Furthermore, in situ imaging allows the growth of nanopores during irradiation to be followed at RT and at 300 °C providing valuable insights into the mechanism responsible for the nanostructuring.