Scanning gate spectroscopy and its application to carbon nanotube defects.

Hunt, Steven R; Wan, Danny; Khalap, Vaikunth R; Corso, Brad L; Collins, Philip G · Nano Lett · 2011

basic_science · Level V

Where this comes from

Abstract

A variation of scanning gate microscopy (SGM) is demonstrated in which this imaging mode is extended into an electrostatic spectroscopy. Continuous variation of the SGM probe's electrostatic potential is used to directly resolve the energy spectrum of localized electronic scattering in functioning, molecular scale devices. The technique is applied to the energy-dependent carrier scattering that occurs at defect sites in carbon nanotube transistors, and fitting energy-resolved experimental data to a simple transmission model determines the electronic character of each defect site. For example, a phenolic type of covalent defect is revealed to produce a tunnel barrier 0.1 eV high and 0.5 nm wide.

Medical subject headings