Our goal is to develop and demonstrate ‘designer’ cold cathode electron sources with tunable parameters (bandgap, efficiency, optical absorption) that outperform present technologies by an order of magnitude in terms of efficiency and lifetime, where success in either of these metrics is considered transformational.
We introduce fundamentally new approaches to address decadal weaknesses in performance and enable cathode properties to be tuned or engineered for specific DOE/LANL missions and related applications. The comprehensive nature of this project requires a focused multi-path, multi-disciplinary approach.
The goal is to engineer two-dimensional (2D) membranes, such as graphene, to serve as a transparent gas barrier shield that does not hinder photoemission but does isolate the cathode surface from reactive gas species without physical damage induced by the high current density electron beam, thus preventing contamination and yielding longer lifetime.
We ensure that performance gains using our novel photocathode concepts are cast within the framework of realistic cathode design and the constraints of a vacuum environment.
We also mature and integrate theoretical photoemission models that account for and predict the effect of the above techniques on local electron density function and other parameters which determine photoemissivity. Measurement of quantum efficiency, spectral response, lifetime, and emittance add to the multiple material characterization techniques to provide a comprehensive picture of cathode performance.
