Synergistic enhancement of carbon nanotube field emission properties through copper nanoparticle flake decoration under argon and nitrogen gas plasma

Exploring carbon nanotubes (CNTs) for their low turn-on field and rapid emission has been a key focus in developing an optimal vacuum-based electron emitter. Despite the potential of CNTs for emission applications, specific limitations impact their overall efficacy. This study focuses on overcoming these limitations by altering the surface morphology of CNTs through the decoration of Cu nanoparticle (Cu NP) flakes via an Ar + N₂ gas-based plasma process at different plasma powers. The field emission parameters demonstrate substantial improvements, including a reduced turn-on field $\left(E_{\mathrm{to}}\right)$ from $2.631\to 1.917V/\mathrm{\mu m}$ and threshold field $\left(E_{\mathrm{th}}\right)$ from $3.768\to 2.552V/\mathrm{\mu m}$, an increment in a macroscopic emission current density $\left(J\right)$ from $6.587\to 46.426\mathrm{mA}/{\mathrm{cm}}^2$, and a field enhancement factor $\left(\beta \right)$ enhanced from $2478\to 3977$, respectively. The decorated CNT field emitters meet orthodox field emission hypothesis criteria, suggesting their potential for vacuum electronic device applications.