In-service change in radiant power of infrared LEDs

Abstract

At present infrared light emitting diodes are used in diverse scanning and optical security systems of nuclear and power plants. The purpose of work is research reducing radiant power during step-by-step accelerated test at higher ambient temperature. The objects of research are infrared light emitting diodes based on dual AlGaAs heterostructures. Two-stage reduction of radiant power has been revealed: first, it is decreased since the original defect structure is rearranged during the operating time; second, new structural defects appear during the further operating time. Moreover, devices are divided into three characteristic groups in view of the second stage, which probably have the same defect with three quasi-stationary states. We assume origination of this defect is caused by production technology of light emitting diodes.