Effect of multifold trapping of carriers on transient photocurrent in amorphous semiconductors

This paper considers the conduct of the density of carriers under conditions of step-by-step generation (continuous illumination) It is shown that this conduct has some interesting features: in particular, the density of mobile carriers determining the transition photocurrent, passes through the maximum before its stationary level is established. The characteristics of the maximum and the form of the curve of the transition photocurrent depend on such important parameters as the depth of the energy distribution of local states, the rate of generation, the capture cross section and recombination, etc. Thus, by interpreting the experimental data on photoconductivity in terms of theory presented later, it is possible to obtain information concerning energy-band structure and the parameters of real disordered materials. Specimens of high resistance materials, illuminated by light or exposed to the action of some kind of ionizing radiation, are considered. The illumination (or irradition) beginning at the moment t = 0, continuously and uniformly with respect to volume generates G electron-hole pairs in unit volume in unit time.