A study of the NEA photocathode activation technique on GaAs(Zn): Cs: O - Cs model

摘要

In this paper we review simply the surface models. These models have several technical problems not solved appropriately except for having deficiency themselves. So we present a new negative electron affinity (NEA) photocathode photoelectric emission model: [GaAs (Zn): Cs]: O -Cs. After discussing photocathodes activation technique on the model, we design a activation technique, which increases the Cs current to decrease the first peak in appropriate degree after using smaller Cs current to achieve the first peak of photoemission (GaAs (Zn)-Cs dipole layer), then set out Cs-O alternation and do not end the technique until gaining maximal photoemission (Cs-O-Cs dipole layer), in the photocathodes with GaAs (Zn) (100)2x4 reconstruction surface. In the present material configuration and level of technique, it is difficult that the integral sensitivity of cathode excess 3500μA/lm. However, it is likely to excess 4000μA/lm by varied doping As-rich GaAs (Zn) (100)2x4 reconstruction surface.