Title screen

There are two distinctive regions can be identified (low (LC) and high currents (HC)) of a watt-ampere (W-I) characteristic of initial LEDs based upon GaP with 590 nm wavelength. The established patterns differ in the exponent. At the same time, the LC region corresponds to an increase in the efficiency of conversion of operating current into light radiation, and the HC region is a slow decline with an increase in the operating current. As a result of irradiation with gamma-quanta in the passive power mode, the change in the shape of W-I characteristic is established, which can be characterized by an increase in the threshold current separating the LC and HC regions with an increase in the irradiation dose. The change in the emissive power of the LEDs and the shift of the threshold current occurs in two stages: in the first stage, the emissive power decreases due to radiation-stimulated rearrangement of the initial defect structure. At the same time, with an increase in the radiation dose, a partial recovery of the emissive power is observed against the background of its overall decrease. At the end of the first stage, the dependence of the damage coefficient on the operating current density in measurements of the W-I characteristics is manifested explicitly. The second stage of reducing the emissive power due to the introduction of radiation defects. In this case, the damage coefficient does not depend on the working current density, and the observed differences are due to the fact that by the end of the first stage its contribution to the overall reduction in emissive power is inversely proportional to the working current density. The established patterns can be used at the stage of designing the LEDs to substantiate the choice of the optimal value of the operating current density and to predict the resistance to irradiation with gamma rays.