Direct measurement of emission current distribution of Spindt-type field emitters

Abstract

A specially designed Spindt-type emitter array is used to study field emission characteristics of the Spindt-type field emitter. Each pixel in the array contains only one tip, is independently addressable, and is spaced 110 μm from the adjacent pixels. The pixels are electrically and optically distinguishable from each other. The emission current distribution of 2560 field emitters in an array is directly measured as a function of gate voltage. The ratio of maximum current to minimum current is as high as 100:1. There are two peaks observed in the current distribution. The position of the high current peak is strongly dependent on the gate voltage, while the position of the low current peak is less sensitive to the gate voltage. The variations in beam size and beam position of individual field emitters are also measured. These variations within individual emitters are partly responsible for large beam size observed in field emission displays with pixels containing hundreds of emitters. Change in the current distribution of individual emitters was recorded as the emitters were aging. Statistically, the emitters operating at high current age faster than those at low current.