Studying Carbon Nanotube Metal Contacts using Band-Specific Overlap Density of States
Abstract
Carbon nanotubes (CNTs) are of great interest because of their incredible material properties. In fact, carbon nanotubes from the same series, i.e. the same number of carbon atoms in each layer, have different material properties depending on the orientation of hexagonal grid of carbon atom making up the tube wall. CNTs can have metallic, semi-metallic or even semiconducting electronic band structures. This makes them ideal to use in microelectronic building blocks such as transistors and interconnects. However, when engineering such microelectronic devices, CNTs must be attached to metal contacts. The CNT-metal interface in these contacts are of vital for the performance of the device and thus understanding the nature of CNT-metal contacts are of importance. We will study the band-specific carbon-metal overlap density of states (ODOS) in order to understand which metals are suitable as contacts for CNTs and carbon nanomaterials in general. By screening all possible metals, we will be able to not only investigate what metals are good candidates for contacts, but also if certain metals are good at electron-conduction or hole-conduction specifically. And similarly, if certain metals are good contacts for majority spin or minority spin. For this we will also use methods that include spin-orbit coupling.
