Highly enhanced and temporally stable field emission from MWCNTs grown on aluminum coated silicon substrate

Abstract

In this work, a detailed field emission study of multi-walled carbon nanotubes (MWCNTs) grown on Si and Al coated Si substrates is reported. Morphological and microstructural studies of the films show higher entanglement of CNTs in the case of CNT/Si film as compared to CNT/Al/Si film. Raman studies show that the defect mediated peak (D) is substantially suppressed as compared to graphitic peak (G) resulting in significant reduction in ID/IG value in CNT/Al/Si film. Field emission (FE) current density of CNT/Al/Si film (∼25 mA/cm2) is significantly higher as compared to that of CNT/Si film (∼1.6 mA/cm2). A substantial improvement in temporal stability is also observed in CNT/Al/Si film. This enhancement in field emission current is attributed to strong adhesion between substrate and CNTs, low work function, high local field enhancement factor at the CNT tips and less entanglement of CNTs grown on Al/Si. The temporally stable CNT/Al/Si cold cathode can be a potential candidate to replace conventional electron sources in prototype devices.

High performance field emission of silicon carbide nanowires and their applications in flexible field emission displays

“…6 Generally, the field emission process is a theoretical model proposed by Fowler and Nordheim, which is based on quantum mechanical tunneling. 7,8 In order to make highly performance field emission emitters having large emission current, low turn-on and threshold fields, there are two challenges to enhance field emission properties of emitters like (i) lowered work function, (ii) increased field enhancement factor of the emitters. For instance, Naik et al has reported that vertical aligned ZnO nanosheet arrays have lower turn-on field and good field emission current stability owing to increased field enhancement factor.…”

Improved field emission from indium decorated multi-walled carbon nanotubes

“…Firstly, homogeneous solution (0.02 gm/ml) of ferrocene and xylene was prepared. The prepared solution was used for CNT growth on the silicon substrate at 730 • C in the higher zone with solution vaporizing temperature of 450 • C in the lower zone as reported earlier [37]. The grown CNT films were coated with In metal of two different thicknesses (50 nm, 100 nm) using a thermal evaporation technique at a base pressure of 5 × 10 −5 mbar.…”