Preparation and evaluation system for NEA GaN photocathode

摘要

Toobtainandevaluatenegativeelectronaffinity(NEA)GaNphotocathode,preparationandevaluationsystemhasbeendesigned.Thesystemincludesmulti-informationtestsystem,ultrahighvacuum(UHV)activationsystem,andsurfaceanalysissystem.GaNphotocathode,whichhadbeenetchedbya2:2:1solutionofsulfuricacid,hydrogenperoxideandde-ionizedwater,wasanalyzedbythesurfaceanalysissystem.ThentheGaNphotocathodewastransferredtotheUHVsystemwhereitwascleanedbyheatingat710#8451;,andsoonwasactivatedbyCs/O.Byuseofthemulti-informationtestsystem,vacuumlevelandcompositionoftheresidualgaswererecordedduringtheheatingprocess,photocurrentwasrecordedduringtheactivation,andquantumefficiencyofNEAGaNphotocathodewastested.