Study on spectral response characteristics of NEA GaAlAs/GaAs vacuum photodiode based on external electric field

In this paper, GaAlAs/GaAs vacuum photodiodes are used to test the spectral response of different external electric fields, and the influence of external electric field on NEA GaAlAs/GaAs photocathode is analyzed. Based on the spectral response curves under different bias voltages, the external voltage increases and the corresponding spectral response sensitivity increases. As the bias voltage increases, the sensitivity of the spectral response increases slowly and gradually becomes saturated. This is mainly due to the fact that under the action of a strong field, the photoelectron obtains a sufficiently high energy to escape into the vacuum, resulting in a spectral response sensitivity tending to saturation.