Project: Electron source Insulator on Conductor

Contact: E. Salançon

Here is an electron source that challenges the physicist!A small insulating crystal (<1μm lateral size and <50nm thickness) deposited on a conductor (carbon, tungsten...) emits electrons when the conductor is negatively biased relative to an extractor. The emission characteristics follow a Fowler-Nordheim process over more than 10 orders of magnitude before reaching saturation and the angular emission intensities reach hundreds of μA/sr. The applied external electric field is of the order of one V/μm, which for a cold emission process is very surprising. Typically, field emission requires fields of a few V/nm.We are interested, both in the potential applications of this process but also in the fundamental understanding of the mechanisms involved.