Time-delayed charge-injection effects on photocurrent shape in a double layer

Transient photocurrents of double-layer structures were simulated by a rand om walk through a cubic lattice in this work. The canonical technique of ti me of flight was simulated to find the characteristics of the photocurrents shape when each layer had a different mobility. The results reproduce the main features of the experimental data from similar real experiments report ed in the literature. Also, the origin of the peak shape of photocurrents i s discussed and it is shown that it is related to a stochastic process whic h forces the out-of-equilibrium charge carriers to be injected from one lay er to the other within a period of time (t,t+dt) as given by a time-depende nt probability phi(t)dt.