Dependence of aging on inhomogeneities in InGaN/AlGaN/GaN light-emitting diodes

Changes of properties of green LEDs based on InxGa1-xN/AlyGa1-y/GaN heteros tructures were studied during 150 divided by 200 hours at currents J = 30 d ivided by 80 MA. The radiation intensity at low currents (0.1 divided by1 m A) is quite sensitive to such an aging, it falls down 10 divided by 100 tim es. Quantum efficiency and spectral parameters at normal currents (J = 10 m A) change non-monotonically during aging, some degradation is observed afte r 168 hours. The degradation is observed also after a short (< 1 min) perio d of reverse current. These phenomena are discussed in terms of under thres hold defect's formation and their migration in the space charge region of p -n-heterojunction, Potential fluctuations in the space charge region are qu ite sensitive to this process.