S20 photocathodes grown by molecular-beam deposition

S20 photocathodes have been grown by solid-source molecular-beam deposition (MBD). The unactivated absorbing layer exhibits a maximum response of 29 mA/W at 430 nm while the photocathode shows a sensitivity and a quantum efficiency of 74 mA/W and 22% at 430 nm. This corresponds to a white sensitivity of 200 muA/lm which is already comparable to commercial S20 photocathodes. In addition, the MBD fabrication cycle takes five times less time than the actual industrial process.