Exciton dissociation and stark effect in the carbon nanotube photocurrent spectrum.
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.
Mohite
Aditya D
AD
Department of Electrical and Computer Engineering, University of Louisville, Louisville, Kentucky 40292, USA.
Gopinath
Prasanth
P
Shah
Hemant M
HM
Alphenaar
Bruce W
BW