Diffusion Model for Describing Relaxation Process in an Electron-Depleted Semiconductor Layer of a Photocathode

A diffusion model has been developed as part of the photoemission model of picosecond electron bunches with a strong electromagnetic field. The model makes it possible to describe the filling of a metal substrate with electrons in a predepleted semiconductor layer of a photocathode. The analytical dependences of the distribution of electron concentration in the semiconductor layer and time dependences of charge of the semiconductor layer were plotted with and without considering the external electric field. It is possible to measure the relaxation time (the time during which the charge of the semiconductor layer decreases to a given value), which is the next step in the development of the photoemission model.