title: Spatially resolved electrostatic potential and photocurrent generation in carbon nanotube array devices.
abstract: 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.
authors: Institute of Nanotechnology, Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany.
authors: Michael
authors: M
authors: Engel
authors: Mathias
authors: M
authors: Steiner
authors: Ravi S
authors: RS
authors: Sundaram
authors: Ralph
authors: R
authors: Krupke
authors: Alexander A
authors: AA
authors: Green
authors: Mark C
authors: MC
authors: Hersam
authors: Phaedon
authors: P
authors: Avouris
mesh_terms: D004574:Electromagnetic Fields; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008027:Light; D008422:Materials Testing; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000528:radiation effects*; D012666:Semiconductors
chemical_list: D037742:Nanotubes, Carbon