AN APPROACH TO MODELING TOTAL-DOSE IONIZING-RADIATION EFFECTS IN HG1-XCDXTE PHOTODIODES USING PISCES II-B

We have modified a 2-D numerical device simulator to account for the e lectrical characteristics of mercury cadmium telluride (MCT), and comp ared the simulated current-voltage (I-V) results with measurements. Fo r diodes not dominated by tunneling or other surface effects, the simu lated curves match the measurement within the experimental limitations . The modified code can now be used to investigate the changes in I-V characteristics of irradiated diodes, by adding the appropriate models . We show the results of an investigation of the band to band tunnelin g in these diodes, which theory predicts is a dominant current produci ng mechanism after irradiation. The I-V curves closely match those of irradiated diodes if radiation induced trapped surface charge is taken into account.