Excellent high temperature field emission behavior with an ultra-low turn-on field and reliable current emission stability from SiC@SiO2@graphene nanoarray emitters

Abstract

In the present work, in order to obtain a promising material, SiC@SiO₂@graphene nanoarrays with numerous flake-like graphene coatings have been prepared on a Si substrate through a simple chemical vapor deposition (CVD) approach. The field emission (FE) measurements show that the turn-on field (E_to) of the as-synthesized SiC@SiO₂@graphene nanoarrays is decreased dramatically from 1.75 V μm⁻¹ to 0.73 V μm⁻¹ when temperature is increased from room temperature (RT) to 500 °C, which is superior to most SiC one-dimensional (1D) nanomaterials. The current fluctuation of the emitters at RT and 200 °C is approximately ±1.3% and ±1.7%, respectively, suggesting remarkable emission efficiency and stability of the sample. The excellent FE behavior is mainly attributed to the distinctly increased number of electron emission sites and the Fermi level (E_f) adjustment caused by the multilayer heterostructure as well as the increased temperatures. Based on the structural components of the nanoarrays, a reasonable “Stripping Reconstruction” mechanism model has been first established. It is believed that not only can the as-synthesized SiC@SiO₂@graphene nanoarrays be utilised as promising emitters under high temperatures, but also the proposed mechanism model and the multilayer decoration strategy are valuable for the FE enhancement of other 1D nanomaterials.