Mechanism and Regularity for Luminous Flux Decreasing of Efficient Small Powered LEDs Based on GaN/InGaN Structures at High Current Density

Measurements of the luminous flux of efficient low-power green light emitting diodes based on In-GaN/GaN hetero-structures at a stable current density (2.5–3.5) times higher than the nominal one have been carried out. On the basis of the ABC model and the mechanism of subthreshold formation of point defects, an analytical dependence of the luminous flux decline in time has been obtained, modelling the behaviour of the corresponding experimental dependences with a high degree of accuracy. It is established that the degradation of LEDs luminous flux at a fixed direct current follows the inverse square law of the operating time. The initial period of rapid degradation, associated with changes in the state of indium micro-inclusions in the Inx-Ga1‑xN solid solution, was revealed