Highly uniform and stable n-type carbon nanotube transistors by using positively charged silicon nitride thin films

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal

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Author(s)

  • Tae-Jun Ha
  • Kevin Chen
  • Steven Chuang
  • Daisuke Kiriya
  • Ali Javey

Detail(s)

Original languageEnglish
Pages (from-to)392-397
Journal / PublicationNano Letters
Volume15
Issue number1
Publication statusPublished - 14 Jan 2015
Externally publishedYes

Abstract

Air-stable n-doping of carbon nanotubes is presented by utilizing SiNx thin films deposited by plasma-enhanced chemical vapor deposition. The fixed positive charges in SiNx, arising from +Si ≡ N3 dangling bonds induce strong field-effect doping of underlying nanotubes. Specifically, an electron doping density of ∼1020 cm-3 is estimated from capacitance voltage measurements of the fixed charge within the SiNx. This high doping concentration results in thinning of the Schottky barrier widths at the nanotube/metal contacts, thus allowing for efficient injection of electrons by tunnelling. As a proof-of-concept, n-type thin-film transistors using random networks of semiconductor-enriched nanotubes are presented with an electron mobility of ∼10 cm2/V s, which is comparable to the hole mobility of as-made p-type devices. The devices are highly stable without any noticeable change in the electrical properties upon exposure to ambient air for 30 days. Furthermore, the devices exhibit high uniformity over large areas, which is an important requirement for use in practical applications. The work presents a robust approach for physicochemical doping of carbon nanotubes by relying on field-effect rather than a charge transfer mechanism.

Research Area(s)

  • CMOS, field-effect transistors, n-FETs, single-walled carbon nanotubes, surface doping

Citation Format(s)

Highly uniform and stable n-type carbon nanotube transistors by using positively charged silicon nitride thin films. / Ha, Tae-Jun; Chen, Kevin; Chuang, Steven; Yu, Kin Man; Kiriya, Daisuke; Javey, Ali.

In: Nano Letters, Vol. 15, No. 1, 14.01.2015, p. 392-397.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal