Simulation of silicon PIN photodiodes for use in space-radiation environments

A computer program for the simulation of semiconductor devices has been developed and applied to the analysis of radiation effects on Si PIN photodiodes. The study has allowed the authors to propose useful analytical models related to such optical and electrical device parameters as peak spectral response and dark current. Peak spectral response has shown a marked dependence on device layers dimensions. Dark current has demonstrated linear increase with intrinsic layer length and proton-radiation fluence. But the most important obtained result has been the determination of a particular set of semiconductor P-, I- and N-layer thicknesses, for given values of total device length and incident light intensity, that minimize radiation effects during photodiode operation in space environments up to high particle fluences.