Abstract
Spectroscopic, time-resolved scanning photocurrent microscopy is shown to distinguish the intrinsic photoresponse of monodisperse semiconducting (99%) single-walled carbon nanotubes (SWCNTs) from the extrinsic photoresponse of the substrate. A persistent positive photocurrent induced by near-infrared excitation is attributed to the generation of free carriers by inter-band excitation in SWCNTs. For shorter excitation wavelengths, absorption by the Si substrate generates two types of photocurrent: a transient positive photoresponse, identified as a displacement current, and a persistent negative photocurrent that arises from photogating of the SWCNT thin film.
Original language | English (US) |
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Article number | 083104 |
Journal | Applied Physics Letters |
Volume | 102 |
Issue number | 8 |
DOIs | |
State | Published - Feb 25 2013 |
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)