Extrinsic and intrinsic photoresponse in monodisperse carbon nanotube thin film transistors

Erik Sczygelski, Vinod K. Sangwan, Chung Chiang Wu, Heather N. Arnold, Ken Everaerts, Tobin J. Marks, Mark C. Hersam, Lincoln J. Lauhon

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)


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 languageEnglish
Article number083104
JournalApplied Physics Letters
Issue number8
Publication statusPublished - Feb 25 2013

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

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