Transient optical double injection in insulators

The transient analysis for optical double injection into a perfect insulator is presented for arbitrary levels of pulsed injection. Exact solutions, in the absence of trapping and neglecting diffusion, are obtained for the transient behavior of the total current density, the electric field distribution, the space-charge distribution, and the conduction current density. The results are valid up to the meeting time of the leading fronts of the injected carrier pulses. Numerical solutions of the transcendental equation for the meeting time are obtained for several values of carrier injection level and relative mobilities. Some of the analytic results have been verified experimentally in anthracene crystals using pulsed light to simultaneously inject carriers at both electrodes. The total current density for step-function illumination under space-charge-limited double-injection conditions is also obtained. © 1971 The American Institute of Physics.