The pulse laser technique was employed to study the kinetics of the diffusion processes which follow electron photoinjection from metallic lithium into the solid electrolyte passivating film on the lithium∣solution interface. Solutions of LiClO4, LiAsF6, and LiPF6 in the mixed solvents propylene carbonate+dimethoxyethane and ethylene carbonate+diethyl carbonate were used. A systematic comparison of the experimental photopotential relaxation curves recorded under various experimental conditions (temperature, film thickness and conductivity) with the corresponding theoretical equations was performed. The electron emission length (about 1 nm) has been estimated. The electron diffusion coefficient and activation energy of diffusion calculated from out transient photopotential curves have been found to be close to these values related to the ionic carriers in the solid electrolyte layer. A possible mechanism of photoelectron transfer in the solid electrolyte layer on lithium is discussed.