Mechanisms of ion beam modification of nanowires and nanotubes
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2017-08-18 |
| Journal | Helda (University of Helsinki) |
| Authors | Wei Ren |
Abstract
Section titled āAbstractāNanowires (NWs) and nanotubes (NTs) are considered to be of great importance for future nanotechnology applications, due to the roles of dimensionality and small system size. Potential applications of NWs and NTs range from field-effect transistors to biological applications. However, the one-dimensional (1D) nanostructures and most of their applications are still in an early stage of technical development. There are several issues that need to be addressed before they are ripe for industrial applications.\n\nIrradiation has been widely used in semiconductor industry to modify the properties of materials since the 1950s. Irradiation in 1D nanomaterials has been studied to tailor the mechanical, electronic, optical and even magnetic properties in a controlled manner, to improve the functionality of the devices based on the 1D nanomaterials. \n\nThis thesis focuses on the structural and mechanical modifications of the 1D nanomaterials under energetic ion irradiation, as well as the formation mechanisms of the composites of the functional one-dimensional nanomaterials to improve their usage. In the first part, we studied the defect production of GaN NWs under Ar irradiation. The difference of defect production between NWs and the bulk counterpart was studied. The effect of the large surface-area-to-volume ratio was found to play an importance role in defect production in NWs. The irradiation energy of the maximum damage production in the NWs has been obtained. In the second part of the thesis, we studied the formation of the composite nanomaterials of diamond-like-carbon (DLC) and carbon nanotubes (CNTs). We used the classical MD method to simulate the deposition process of carbon atoms on the CNT systems to provide the atomic insights into structural changes. The results show that high-sp$^3$-content DLC can be formed provided the deposition conditions allow for sidewards pressure to form from a substrate close beneath the CNTs.
Tech Support
Section titled āTech SupportāOriginal Source
Section titled āOriginal Sourceā- DOI: None