Application of ionization type infrared image converter systems for study of physical properties of photodetector

Infrared (IR) photodetector instabilities of IR image converter was studied experimentally in a wide range of the gas pressures (p= 28-342 Torr), interelectrode distances (d1 = 50 µm d2 = 50 ? 320 µm) and different diameters (D= 12-15 mm) of the photodetector areas. The current voltage characteristics (CVC) of the double gas discharge system with GaAs semiconductor wasstudied. While being driven with a stationary voltage, it generates current instabilities with different amplitudes of oscillation. It was unambiguously proved that instabilities in the IR image converter may be provoked by a photodetector, depending on the experimental conditions. N-shape instabilities of CVC was determined. The presence of deep electronic levels of defects, socalled EL2 centers, give rise to the N-type NDR of the material, as a consequence, to oscillations in current when a dc voltage of a high enough magnitude is applied to a GaAs photodetector. Due to the gas discharge dual-range, Current-Voltage and Current-Time charts modulation was observed. In addition, for large distance between electrodes, hysteresis curves were obtained.