1.
Nano Lett
; 8(1): 142-6, 2008 Jan.
Article
in English
| MEDLINE
| ID: mdl-18047383
ABSTRACT
The field-dependent photocurrent spectrum of individual carbon nanotubes is measured using a displacement photocurrent technique. A series of peaks is observed in the photocurrent corresponding to both excitonic and free carrier transitions. The photocurrent peak corresponding to the ground state exciton increases by a factor of 200 beyond a critical electric field, and shows both red and blue shifts depending on the field regime. This provides evidence for field-induced mixing between excitonic and free carrier states.