Enhanced electron emission has been observed from lead zirconate-titanate (PZT) surfaces into which arrays of microcavities have been fabricated by nanopowder blasting. Arrays of microcavities, each having an elliptical cross-sectional geometry with major and minor axis lengths of 800 and 600m, respectively, and depths adjustable from 40 to 300m, exhibit a pronounced dependence of the emitter electron current on microcavity depth. For electric field strengths at the emitter surface of ∼5-12V/m, the RMS current density generated by an array of 250m-deep microcavities with a packing density of 214±2cm-2 ranges from ∼3mAcm-2 to beyond 8mAcm-2, or more than a factor of five larger than that produced from a planar PZT surface.
ASJC Scopus subject areas
- Electrical and Electronic Engineering