Reaching homogeneous field emission current from clusters of emitters with nonuniform heights

Abstract

In field electron emission from pointed structures in a cluster or in an array, electrostatic depolarization due to neighboring emitters diminishes the local field enhancement factor (FEF). This effect can limit the maximum macroscopic emission current from devices. If emitters in a cluster are regularly spaced and uniformly tall, the local FEF will always present significantly larger values at the edges, making most of the cluster ineffective. In this work, we explore conducting emitters in a cluster that are not uniformly tall and numerically calculate the local electrostatic field and the macroscopic emitted current over classical emitter’s surfaces using the Murphy–Good emission model. Our results show the conditions to homogenize and, therefore, optimize the emission current extractable from the cluster.