Analysis of a laser post-process on a buckypaper field emitter for high and uniform electron emission

This study reports a laser irradiation process to enhance the field emission properties of buckypaper, which is a thin sheet of high-loading carbon nanotube networks. The scanning laser treated the selected regions of buckypaper to activate carbon nanotube (CNT) emitters. This post-process causes a decrease in turn-on field and increases the field enhancement factor (β), luminance intensity, and uniformity of buckypaper emitters. The phosphorescence luminance intensity and uniformity of buckypaper emitters are measured and characterized. The low turn-on field of 0.56 V μm-1, highest average luminance intensity of 235.9/255, and uniformity of 99.8% are achieved by adjusting the machining parameters of laser power, laser lens motion speed, laser resolution, laser beam size, and pattern orientation. Those parameters relate to the field emission properties of β, turn-on electric field, luminance intensity, and uniformity. Using design of experiment (DOE) methodology, the optimal parameter settings for high and uniform electron emission of a buckypaper emitter are obtained within fewer experimental runs.