Spatially resolved electrostatic potential and photocurrent generation in carbon nanotube array devices

Michael Engel, Mathias Steiner*, Ravi S. Sundaram, Ralph Krupke, Alexander A. Green, Mark C. Hersam, Phaedon Avouris

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

21 Scopus citations


We have used laser-excited photocurrent microscopy to map the internal electrostatic potential profile of semiconducting single-walled carbon nanotube (S-SWCNT) array devices with a spatial resolution of 250 nm. The measurements of S-SWCNTs on optically transparent samples provide new insights into the physical principles of device operation and reveal performance-limiting local heterogeneities in the electrostatic potential profile not observable with other imaging techniques. The experiments deliver photocurrent images from the underside of the S-SWCNT-metal contacts and thus enable the direct measurement of the charge carrier transfer lengths at the palladium-S-SWCNT and aluminum-S-SWCNT interfaces. We use the experimental results to formulate design rules for optimized layouts of S-SWCNT-based photovoltaic devices. Furthermore, we demonstrate the external control of the electrostatic potential profile in S-SWCNT array devices equipped with local metal gates.

Original languageEnglish (US)
Pages (from-to)7303-7310
Number of pages8
JournalACS nano
Issue number8
StatePublished - Aug 28 2012


  • nano-optics
  • nanoelectronics
  • self-assembly

ASJC Scopus subject areas

  • Materials Science(all)
  • Engineering(all)
  • Physics and Astronomy(all)

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