  The development of high-performance photocathodes is a key challenge for
future accelerator and particle physics applications. In this paper
photocathode growth through molecular beam epitaxy is introduced as a promising
technique to obtain robust, highly efficient alkali-antimonide based
photocathodes. Recent research shows that the quantum efficiency of
photocathodes can be significantly enhanced through control of the photocathode
crystallinity. Molecular beam epitaxy allows for cost-effective growth of
large-area photocathodes with excellent control of the stoichiometry and
crystallinity, making photocathodes with peak quantum efficiencies exceeding
35% routine.
