Photoemission from Kndash;Te photocathodes

摘要

In this letter the photoemissive properties of Kndash;Te films produced under ultrahigh vacuum conditions are reported. Kndash;Te photocathodes were fabricated by vapor deposition of Te and K onto a Mo substrate into the preparation chamber of the Free Electron Laser of the University of Twente. The highest quantum efficiency obtained at 259 nm was 11.1percnt;, measured just after evaporation; this value decreased in a few minutes to a stable quantum efficiency of 8.3percnt;. The reported results show that Kndash;Te can be considered a promising material for the use as a photocathode in photoinjectors. copy;1996 American Institute of Physics.