Solution-Processed Dielectrics Based on Thickness-Sorted Two-Dimensional Hexagonal Boron Nitride Nanosheets

Jian Zhu, Joohoon Kang, Junmo Kang, Deep Jariwala, Joshua D. Wood, Jung Woo T. Seo, Kan Sheng Chen, Tobin J. Marks, Mark C. Hersam

Research output: Contribution to journalArticle

47 Citations (Scopus)

Abstract

Gate dielectrics directly affect the mobility, hysteresis, power consumption, and other critical device metrics in high-performance nanoelectronics. With atomically flat and dangling bond-free surfaces, hexagonal boron nitride (h-BN) has emerged as an ideal dielectric for graphene and related two-dimensional semiconductors. While high-quality, atomically thin h-BN has been realized via micromechanical cleavage and chemical vapor deposition, existing liquid exfoliation methods lack sufficient control over h-BN thickness and large-area film quality, thus limiting its use in solution-processed electronics. Here, we employ isopycnic density gradient ultracentrifugation for the preparation of monodisperse, thickness-sorted h-BN inks, which are subsequently layer-by-layer assembled into ultrathin dielectrics with low leakage currents of 3 × 10-9 A/cm2 at 2 MV/cm and high capacitances of 245 nF/cm2. The resulting solution-processed h-BN dielectric films enable the fabrication of graphene field-effect transistors with negligible hysteresis and high mobilities up to 7100 cm2 V-1 s-1 at room temperature. These h-BN inks can also be used as coatings on conventional dielectrics to minimize the effects of underlying traps, resulting in improvements in overall device performance. Overall, this approach for producing and assembling h-BN dielectric inks holds significant promise for translating the superlative performance of two-dimensional heterostructure devices to large-area, solution-processed nanoelectronics.

Original languageEnglish
Pages (from-to)7029-7036
Number of pages8
JournalNano letters
Volume15
Issue number10
DOIs
Publication statusPublished - Oct 14 2015

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Keywords

  • Density gradient ultracentrifugation
  • density differentiation
  • graphene
  • h-BN
  • heterostructure
  • isopycnic sorting

ASJC Scopus subject areas

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

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