Planar cold cathodes

A planar cathode is a thin-film emitter deposited on a conducting surface, which emits electrons when an electric field is applied by an anode separated from the film front surface by a a vacuum gap. Field emission (FE) devices offer unique advantages compared to the vacuum tube. Among these are the modest power consumption and the possibility of integration with solid-state electronics. Vacuum microelectronics research has shown the feasibility of fabricating large-area cold cathodes and the possibility for extreme miniaturization of integrated field emitters. However, industrial development of vacuum microelectronic or nanoelectronic devices is more demanding than the academic uses of FE for surface studies. An ideal cathode, from the industrial point of view, can be outlined and characterized by the factors, including room temperature operating condition, small operating voltage, high brightness and efficiency, and long lifetime and reproducible operating conditions.