Comprehensive Survey for the Frontier Disciplines

Abstract

The present status of research on negative electron affinity (NEA) GaN vacuum surface electron source is discussed with considering the latest research conclusions from our country and foreign country. Some valuable results about GaN vacuum electron source have been obtained including the theory of photoemission, the surface depuration method, the activation technique for GaN photocathode, the measurement of spectral response, the characteristics of material etc. The mechanism of photoemission for NEA GaN vacuum electron source is studied preliminarily. The depuration method of obtaining the atom cleanness surface is given. The GaN material is effectively activated with Cs or Cs/O. The spectral response of GaN vacuum electron source material is measured. The material characteristics affecting the quantum efficiency of the electron source are analyzed. The next investigation is also mentioned.