Hybrid density-functional theory study of the work function of single-walled carbon nanotubes

PRES 44

Jamal Uddin, uddin@rice.edu, Verónica Barone, Juan E. Peralta, juanp@rice.edu, and Gustavo E Scuseria, guscus@rice.edu. Department of Chemistry, Rice University, Houston, TX 77005
Carbon nanotubes are promising candidate material for future nano-electronics. The work function is a critical physical quantity that is essential for the understanding of the field emission properties of Single-Walled Carbon Nanotubes (SWNTs). In this work, we present a detailed study of the work function of pristine and doped single-walled carbon nanotubes (SWCNTs) using a novel screened exchange hybrid density functional theory method. Our study shows that for SWCNTs with radii larger than 0.45 nm, the work function tends asymptotically and smoothly to the graphene limit, while for narrower nanotubes the work function exhibits strong dependency on their radius and chiral angle. We also show that doping changes the electronic behavior and alters the work function significantly.