Hot Electron Laser Assisted Cathode Using Electronically Tunable Negative Electron Surfaces-Prospects and Challenges

State-of-the art negative electron affinity cathodes are being considered as promising high-frequency photoemitters because of their reasonably high external quantum efficiency and low mean transverse energies. However, their large-scale application is still limited by their instability and complex fabrication process. In this work, we have designed and fabricated an electronically tunable hot electron laser assisted cathode using negative electron surfaces by employing a facile exsitu fabrication technique. Despite the lack of any optimization, the proof-of-concept device has demonstrated excellent air stability and an external quantum efficiency of ~0.5%. This study can provide insight into the prospects and challenges of designing novel negative electron affinity photocathodes with high quantum efficiency.