title: Adsorption of atomic hydrogen on single-walled carbon nanotubes.
abstract: We have investigated atomic and electronic structures of hydrogen-chemisorbed single-walled carbon nanotubes (SWCNTs) by density functional calculations. We have searched for relative stability of various hydrogen adsorption geometries with coverage. The hydrogenated SWCNTs are stable with coverage of H/C, theta >/= 0.3. The circular cross sections of nanotubes are transformed to polygonal shapes with different symmetries upon hydrogen adsorption. We find that the band gap in carbon nanotubes can be engineered by varying hydrogen coverage, independent of the metallicity of carbon nanotubes. This is explained by the degree of sp(3) hybridization.
authors.affiliation: Department of Physics, Center for Nanotubes and Nanostructured Composites, Sungkyunkwan Advanced Institute of Nanotechnology, Sungkyunkwan University, Suwon 440-746, Korea.
authors.forename: Kyung Ah
authors.initials: KA
authors.lastname: Park
authors.forename: Kwanyong
authors.initials: K
authors.lastname: Seo
authors.forename: Young Hee
authors.initials: YH
authors.lastname: Lee