Abstract by Berg Dodson
Physics and Astronomy
Richard Vanfleet, Robert Davis
Conductivity of the Carbon Nanotube/Substrate Interface
Carbon nanotubes (CNTs) serve as a versatile material for three-dimensional MEMS fabrication. Their unique growth structure – nanoscale elements in a vertical microscale structure – is useful as a scaffold for forming and then infiltrating complex shapes and materials combinations. In order to grow a CNT structure on a conductive substrate there must be a barrier, alumina, between the substrate and the CNT catalyst, iron. We have been studying the electrical properties of the alumina/iron stack in the context of CNT growth. Observation shows the electrical connection between the substrate and CNTs is good despite having to cross the alumina barrier which should be highly insulating. We suggest this electrical connection through the alumina is due to diffusion of the iron catalyst during the CNT growth process and will show electrical and transmission electron microscopy data to support this model.