Growth Kinetics and Structural Characterization of Carbon Nanotubes: From In Situ Observation to Raman Spectroscopy
Vladimir PIMONOV
Team Aggregates and Nanomaterials, Institute of Light and Matter, University Claude Bernard Lyon1
Abstract
Carbon nanotubes (CNTs) remain a model system for studying the relationship between growth conditions, structure, and electronic properties. Their strong structure–property dependence makes control of synthesis a central challenge, but understanding this control requires access not only to the final nanotube structure, but also to the dynamics of its formation. This work combines in situ observation of individual single-walled CNT growth with automated image analysis and post-growth structural characterization.
During my PhD, in situ homodyne polarization microscopy was used to follow the growth of individual CNTs under CVD conditions. Deep-learning-based detection and tracking enabled high-throughput extraction of growth kinetics from low-contrast videos and revealed dynamic instabilities, including transitions between distinct growth regimes. These kinetic measurements were correlated with Raman characterization of the same nanotubes, providing a direct link between growth behavior and structure. The same framework also highlighted the importance of the substrate: Raman studies of individual CNTs grown on quartz showed that the measured vibrational response reflects not only intrinsic nanotube structure, but also interactions with the local environment.
My latest postdoctoral work extends this approach to CNT growth under applied electric field, using environmental TEM to observe growth directly at the nanoscale. Here again, automated analysis is essential for extracting kinetic information from large video datasets and for identifying field-dependent changes in growth, stability, and failure mechanisms. Ongoing work combines these kinetic measurements with Raman-based structural analysis to examine how the electric field affects not only nanotube growth dynamics, but also the resulting nanotube population. Together, these studies illustrate how in situ microscopy, data-driven image analysis, and Raman spectroscopy can be combined to investigate the coupling between synthesis conditions, environment, growth kinetics, and nanotube structure.
Contact : Chris Ewels (PMN)
