title: Controlled n-Type Doping of Carbon Nanotube Transistors by an Organorhodium Dimer.
abstract: Single-walled carbon nanotube (SWCNT) transistors are among the most developed nanoelectronic devices for high-performance computing applications. While p-type SWCNT transistors are easily achieved through adventitious adsorption of atmospheric oxygen, n-type SWCNT transistors require extrinsic doping schemes. Existing n-type doping strategies for SWCNT transistors suffer from one or more issues including environmental instability, limited carrier concentration modulation, undesirable threshold voltage control, and/or poor morphology. In particular, commonly employed benzyl viologen n-type doping layers possess large thicknesses, which preclude top-gate transistor designs that underlie high-density integrated circuit layouts. To overcome these limitations, we report here the controlled n-type doping of SWCNT thin-film transistors with a solution-processed pentamethylrhodocene dimer. The charge transport properties of organorhodium-treated SWCNT thin films show consistent n-type behavior when characterized in both Hall effect and thin-film transistor geometries. Due to the molecular-scale thickness of the organorhodium adlayer, large-area arrays of top-gated, n-type SWCNT transistors are fabricated with high yield. This work will thus facilitate ongoing efforts to realize high-density SWCNT integrated circuits.
authors.affiliation: Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Geier
authors.affiliation: School of Chemistry and Biochemistry, Center for Organic Photonics and Electronics, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.
authors.forename: Karttikay
authors.initials: K
authors.lastname: Moudgil
authors.affiliation: School of Chemistry and Biochemistry, Center for Organic Photonics and Electronics, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.
authors.forename: Stephen
authors.initials: S
authors.lastname: Barlow
authors.affiliation: School of Chemistry and Biochemistry, Center for Organic Photonics and Electronics, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.
authors.forename: Seth R
authors.initials: SR
authors.lastname: Marder
authors.affiliation: Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.|Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.|Department of Electrical Engineering and Computer Science, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Mark C
authors.initials: MC
authors.lastname: Hersam
keywords: Single-walled carbon nanotubes; chemical doping; n-type; thin-film transistors; top-gate