Plasma treatment effects on surface morphology and field emission characteristics of carbon nanotubes

Effect of plasma parameters on growth and field emission of electrons from cylindrical metallic carbon nanotube surfaces

“…charged A type ion decays faster. With increasing electron density and temperature (plasma parameters), ions of type A will decay faster, leading to a decrease in the CNT radius, which is consistent with the experimental observations of Lee et al 18 and Srivastava et al 19 In Fig. 5, we have plotted the variation of the normalized radius a/a 0 for the cylindrical CNT surfaces for different value of the atomic sticking coefficients of atomic species (c A ¼ 0.25, 0.45, 0.75, and 1.0), respectively and for the same parameters as mentioned above.…”

“…The emission from the CNT tip is dominant that has also been reported by Shang et al 34 Our theoretical results are in accordance with the experimental observations of Lee et a1. 18 and Srivastava et al 19 The present work is motivated by important experimental investigations carried out by Lee et al 18 and Srivastava et al 19 According to Srivastava et al, 19 upon an increase in the microwave power, more ionization of the gas occurs, which increases the density of plasma species of relatively higher energy. Moreover, increased nucleation of graphitic clusters is expected to occur, and this leads to the formation of carbon petals of relatively smaller size and higher density at increased microwave power.…”

“…7(a) of Srivastava et al 19 also reveals that the field emission current density increases with microwave power. Lee et al 18 through their experimental study, predict that the plasma treatment can modify the surface morphology and enhance the field enhancement factor of the CNT.…”

“…The field emission properties of CNT and the effect of various factors such as plasma parameters, substitutional atoms, dimensional effects, anodecathode distance, etc., on field emission from CNT have been extensively studied. [16][17][18][19][20][21][22][23][24][25][26][27] Bonard et al 17 have studied the field emission from single walled carbon nanotubes, and a current density of 10 mA/cm 2 was obtained with operating voltages that are far lower than those of other field emitters but show a significant degradation in their performances with time.…”

“…Lee et al 18 have investigated the effect of plasma treatment on the surface morphology and field emission characteristics of CNT and revealed that the plasma treatment can modify the surface morphology and enhance the field emission characteristics of the CNTs.…”