InAs charge-storage photodiode mosaic for infrared vidicon targets

Two-dimensional InAs charge-storage photodiode arrays for electron-beam vidicon applications are being developed. The InAs array diodes exhibit sufficiently low reverse leakage currents for the diodes to be operated in a charge-storage mode with an electron beam scanning at the conventional TV scanning rate of 1/30 second at a diode temperature of 77°K. The measured typical reverse leakage current density at near-liquid-nitrogen temperature is in the range of 5 × 10^-10A/cm²at the reverse bias of 5.5 volts, with minimum background radiation on the diode. For the low-bias region, a study of the reverse current as a function of temperature indicates that the current transport mechanism is thermal in nature, and that it is dominated by the generation current in the space-charge region of the junction.