Thickness-dependent interfacial coulomb scattering in atomically thin field-effect transistors

Song Lin Li, Katsunori Wakabayashi, Yong Xu, Shu Nakaharai, Katsuyoshi Komatsu, Wen Wu Li, Yen Fu Lin, Alex Aparecido-Ferreira, Kazuhito Tsukagoshi

Research output: Contribution to journalArticlepeer-review

209 Citations (Scopus)

Abstract

Two-dimensional semiconductors are structurally ideal channel materials for the ultimate atomic electronics after silicon era. A long-standing puzzle is the low carrier mobility (μ) in them as compared with corresponding bulk structures, which constitutes the main hurdle for realizing high-performance devices. To address this issue, we perform a combined experimental and theoretical study on atomically thin MoS2 field effect transistors with varying the number of MoS2 layers (NLs). Experimentally, an intimate μ-NL relation is observed with a 10-fold degradation in μ for extremely thinned monolayer channels. To accurately describe the carrier scattering process and shed light on the origin of the thinning-induced mobility degradation, a generalized Coulomb scattering model is developed with strictly considering device configurative conditions, that is, asymmetric dielectric environments and lopsided carrier distribution. We reveal that the carrier scattering from interfacial Coulomb impurities (e.g., chemical residues, gaseous adsorbates, and surface dangling bonds) is greatly intensified in extremely thinned channels, resulting from shortened interaction distance between impurities and carriers. Such a pronounced factor may surpass lattice phonons and serve as dominant scatterers. This understanding offers new insight into the thickness induced scattering intensity, highlights the critical role of surface quality in electrical transport, and would lead to rational performance improvement strategies for future atomic electronics.

Original languageEnglish
Pages (from-to)3546-3552
Number of pages7
JournalNano Letters
Volume13
Issue number8
DOIs
Publication statusPublished - 2013 Aug 14
Externally publishedYes

Keywords

  • Two-dimensional material
  • chalcogenide
  • electrical transport
  • field-effect transistor
  • scattering mechanism

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

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