Field emission properties of a graphene/polymer composite

J Nanosci Nanotechnol. 2013 Nov;13(11):7689-94. doi: 10.1166/jnn.2013.7847.

Abstract

Thin graphene/polymer sheet composites were fabricated using easily soluble expanded graphite (ESEG), and their field emission (FE) parameters were examined. Due to the high dispersability of ESEG, a stable graphene suspension was prepared by ultrasonication in toluene without the need for a surfactant. The suspension consisted of exfoliated graphene sheets with a thickness of 1 - 2 nm. Using a calendering process, the solution was further shear mixed with ethyl cellulose to obtain a well-dispersed graphene/polymer composite. The composite was screen printed onto a conducing substrate to fabricate the FE cathode layers. The FE measurements were taken in a diode configuration at an applied electrostatic field and inter-electrode distance of 1.7 to 6 V/microm and approximately 200 microm, respectively. The threshold turn-on-field was approximately 3.5 V/microm at a current density of approximately 10 microA/cm2 with a corresponding mean field enhancement factor of 1350 +/- 50. Emission occurred mainly from the edges and bends of the graphene layers. The luminescence uniformity of the composite cathode layers was examined using a phosphor-coated anode.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cellulose / chemistry*
  • Electric Conductivity
  • Electrodes*
  • Equipment Design
  • Equipment Failure Analysis
  • Graphite / chemistry*
  • Luminescence*
  • Materials Testing
  • Nanostructures / chemistry*
  • Nanostructures / ultrastructure*
  • Particle Size
  • Semiconductors*
  • Static Electricity

Substances

  • Graphite
  • Cellulose