Influence of preliminary irradiation by gamma-quanta on development of catastrophic failures during operation of IR-LEDs

Abstract

We have considered the influence of preliminary irradiation by 60Co gamma quanta on development of catastrophic failure during long-term operation of IR-LEDs based upon dual AlGaAs heterostructures. Irradiation was realized in passive power mode of the LEDs prior to aging. Two specific doses of irradiation were used. The first irradiation dose corresponded to the first stage of emission power drop of the LEDs irradiated by gamma-quanta, which is attributed to the radiation-stimulated reconstruction of the initial defect structure of the LED crystal. The second dose corresponded to the second stage of emission power drop, which is attributed solely to the introduction of radiation defects. Aging under long operating time conditions was simulated by a step-stress approach. We have established that the preliminary irradiation by gamma-quanta can be used in manufacturing technology of LEDs to improve their operating parameters on condition that irradiation doses are chosen in strictly provide area of the radiation-stimulated reconstruction of the initial defect structure.