The Nea Of Gan Photocathode Preparation And Activation Methods

The growth method of GaN based semiconductor had long been a problem that greatly restricted the development of NEA based GaN photocathode.While,in recent years,as a result of the rapid development of the growth technologies,the research of NEA GaN photocathode has turned to be a hotspot.The NEA GaN photocathode have the characteristics of high quantity effectivity(QE), low dark current,the energy of the electrons emitted has a narrow distribution and so on,making it quite attractive for many applications,such as laser detection,disaster predictions,detection of ultra-high voltage discharge, ultraviolate communications,ultraviolate alerting system and so on.The dissertation concentrate on the growth method of the GaN photocathode and the way to activate it.Firstly,the dissertation introduce you the development of the NEA base Gan photocathode and the advantages of it.Except that,it also introduces the latest achievements and applications about it. Then,the dissertation focus on the growth method of a NEA based GaN photocathode and the way to activate.After that,we successfully built the NEA GaN multi-paremeter realtime test system.lt includes a grating monochromator, an ultraviolate optical fiber,a set of micro signal proseccing module,tow programmable power supplys and the industrial computer. We also growed tow kinds of p type GaN samples by MOCVD,one of which uses sapphire as the base and A1N as a buffer layer,and the other uses GaN as a buffer layer, we carried out our experiment with our newly built system,the standard progress of cleaning,activation and test are obeyed.At last,there's some analysis about our experiment results and the curves for the spectacle responce and electron yield of the NEA GaN photocathode are given.