Paired gap states in a semiconducting carbon nanotube: deep and shallow levels.
Several paired, localized gap states were observed in semiconducting single-wall carbon nanotubes using spatially resolved scanning tunneling spectroscopy. A pair of gap states is found far from the band edges, forming deep levels, while the other pair is located near the band edges, forming shallow levels. With the help of a first-principles study, the former is explained by a vacancy-adatom complex while the latter is explained by a pentagon-heptagon structure. Our experimental observation indicates that the presence of the gap states provides a means to perform local band-gap engineering as well as doping without impurity substitution.
Lee
Sungjun
S
School of Physics, Seoul National University, Korea.
Kim
Gunn
G
Kim
Hajin
H
Choi
Byoung-Young
BY
Lee
Jhinhwan
J
Jeong
Byoung Wook
BW
Ihm
Jisoon
J
Kuk
Young
Y
Kahng
Se-Jong
SJ