Abstract: The description of production and transient of photocurrent in semiconductor devices in ionzinong radiation environment is of great importance for Transient Radiation Effects on Electronics Systems(TREES). Physical models of generic description of photocurrent in semiconductors are proposed hare, photocurrent of an actual pn junction has been simulated numerically, and the simulation results are also presented.

Key words: photocurrent, numerical simulation, ionizing radiation, semiconductor devices