title: Variable-force microscopy for advanced characterization of horizontally aligned carbon nanotubes.
abstract: Atomic force microscopy (AFM) performed with variable-force imaging was recently demonstrated to be an accurate method of determining the diameter and number of sidewalls of a carbon nanotube (CNT). This AFM technique provides an alternative to transmission electron microscopy (TEM) when TEM imaging is not possible due to substrate thickness. We have used variable-force AFM to characterize horizontally aligned CNTs grown on ST-cut quartz. Our measurements reveal new aspects of horizontally aligned growth that are essential for enhancing the performance of CNT-based devices as well as understanding the growth mechanism. First, previously reported optimal growth conditions produce a large spread in CNT diameters and a significant fraction of double-walled CNTs. Second, monodispersity is significantly improved when growth temperature is reduced. Third, CNTs with diameters up to 5 nm align to the substrate, suggesting the interaction between CNTs and the quartz lattice is more robust than previously reported.
authors: Department of Physics, Oregon State University, Corvallis, OR, USA.
authors: Ali A
authors: AA
authors: Almaqwashi
authors: Joshua W
authors: JW
authors: Kevek
authors: Rachel M
authors: RM
authors: Burton
authors: Tristan
authors: T
authors: DeBorde
authors: Ethan D
authors: ED
authors: Minot