Mechanism analysis of Gen III LLL image intensifier GaAs cathode photoelectric emission disability

The focus of the third generation image intensifier photocathode sensitivity decreases in the GaAs are analyzed, and proposed solutions,experimental results show that the tube microchannel plate(mcp), screen GaAs cathode discharge gas is caused by decreased sensitivity of the main reasons. Paper used two-layer model, and even negative electron affinity(NET) interface barrier theory of the photoelectric cathode drop mechanism was discussed , when the photocathode emission levels of CO adsorption and other harmful gas, chemical adsorption layer of ionic bond formation will lead to production of cathode surface barrier interfaces. Cathode surface adsorption of the pollutants more ,the interface barrier becomes thicker, the smaller the electron surface escape probability, when the cathode interface thicker barrier to the electron surface escape is zero, the cathode photoemission end of life.