Effect of clay on the surface morphology and field emission properties of screen-printed activated carbon

Surface morphology of the screen-printed activated carbon paste with organophobic montmorillonite clay and electron field emission properties was studied. X-ray diffraction (XRD), and scanning electron microscopy (SEM) were used to evaluate the distribution of filler in the carbon paste and the structure of carbon film. The addition of clay particles improved homogeneous dispersion of carbon in paste, which contributed to the formation of uniform carbon film during screen-printing. The current density J increased significantly, while the threshold electric field Eth decreased when the filler particles were added to the carbon paste. The enhancement of field emission properties is believed to be due to the improvement of the dispersivity and adhesiveness of the paste. The organoclay loading also showed better thermal stability.