Phenomenological Model of Radiation Hardness of LEDs Based on AlGaInP Heterostructures with Multiple Quantum Wells

Abstract

Neutron degradation of LEDs based upon AlGaInP heterostructures (λ=630 nm and λ=590 nm) with multiple quantum wells are presented in the article. For the initial red LED (λ=630 nm) we can clearly distinguish three characteristic regions. In the small current region a low electron injection mode into the active region of the LEDs is observed. Further, as the operating current goes up, there are average and high electron injection in the active LEDs area regions. However, for the LEDY, the difference in the average and high electron injection regions is more pronounced and low electron injection region is absent. The boundary between the average and high electron injection regions can be characterized by the boundary current, which goes up with increasing exposure level. Three regions of electron injection in the active area of LEDs: low, average and high electron injection are illustrated for both types of LEDs under fast neutron irradiation. Based on the established relationships describing the emission power changing, a phenomenological model of the radiation hardness of LEDs based on AlGaInP heterostructures with MQW was shown. The LEDs radiation hardness is determined by the boundary current value, emission power in the low electron injection into the active LEDs area, the initial defective structure.