Study of the degradation of the external quantum efficiency of UV LEDs based on AlGaN/GaN heterostructures grown by chloride-hydride vapor-phase epitaxy

Final stage of the degradation of the external quantum efficiency of AlGaN/GaN UV light-emitting diodes (LEDs), grown by chloride-hydride vapor-phase epitaxy, and high-power InGaN/GaN blue LEDs, produced by metal-organic vapor-phase epitaxy, has been comparatively studied. It is shown that one of these processes leading to a decrease in the quantum efficiency for both types of LEDs is the local defect formation involving the Gold-Weisberg mechanism in a system of extended defects. To prolong the service life of AlGaN/GaN UV LEDs to more than 2000 h, it is necessary to improve the nanostructural arrangement of the material of light-emitting structures and determine the contribution from the AlGaN composition disorder to the degradation of the external quantum efficiency.