Laboratory production of efficient alkali-antimonide photocathodes

An experimental setup and procedures for the preparation of high-quality reflective and semitransparent alkali-antimonide photocathodes in laboratory conditions is described. Absolute quantum efficiency curves for KCsSb and Cs3Sb photocathodes are presented in the spectral range of 250–550 nm; their average quantum efficiency values at 312 nm are 32% and 15%, respectively. The photocathodes are stable in vacuum and in high-purity methane over a few days period. The system also permits photocathode coating with protective films.