Modeling the time-dependent transient radiation response of semiconductor junctions

Analytical one-dimensional time-dependent photocurrent models are developed from new solutions to the ambipolar transport equation. The p-n junction model incorporates the effects of an electric field in the quasi-neutral region, finite diode length, and an arbitrary generation function g=f(x,t). It provides improved accuracy over the Wirth-Rogers and Enlow-Alexander models. An approximate photocurrent solution for p-n-n⁺, n-p-p⁺ , and p-i-n diode junctions is developed considering high-injection effects. Comparison with experimental data shows that a single set of physical parameters is adequate to characterize the model with respect to dose rate, pulse width, and geometry