Length-dependent optical effects in single-wall carbon nanotubes.
Among the novel chemical and physical attributes of single-wall carbon nanotubes (SWCNTs), the optical properties are perhaps the most compelling. Although much is known about how such characteristics depend on nanotube chirality and diameter, relatively little is known about how the optical response depends on length, the next most obvious and fundamental nanotube trait. We show here that the intrinsic optical response of single-wall carbon nanotubes exhibits a strong dependence on nanotube length, and we offer a simple explanation that relates this behavior to the localization of a bound exciton along the length of a nanotube. The results presented here suggest that, for a given volume fraction, the longest nanotubes display significantly enhanced absorption, near-infrared fluorescence, and Raman scattering, which has important practical implications for potential applications that seek to exploit the unique optical characteristics of SWCNTs.
Fagan
Jeffrey A
JA
National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
Simpson
Jeffrey R
JR
Bauer
Barry J
BJ
Lacerda
Silvia H De Paoli
SH
Becker
Matthew L
ML
Chun
Jaehun
J
Migler
Kalman B
KB
Walker
Angela R Hight
AR
Hobbie
Erik K
EK