Gamma Radiation Response of MWIR and LWIR HgCdTe Photodiodes

This paper describes the results of experimental investigation of the gamma radiation response of HgCdTe photodiodes. The devices were fabricated in material grown by liquid phase epitaxy; the p-n junctions were made by ion implantation and passivated with ZnS. The MWIR devices, tested at 120K, showed transient response in reasonable agreement with existing theory and total dose hardness greater than 1 Mrad(Si). The LWIR detectors, tested at 40K, showed a degradation threshold at 10 Krad(H2O). This degradation is not a result of surface inversion resulting from charge trapping in the insulator.