Electromigration-induced failure of GaN multi-quantum well light emitting diode

Degradation of AlGaN-based ultraviolet light emitting diodes

“…This result of Ref. [9] is in agreement with the previous study [2,3], indicating that the main degradation mechanism of GaN-based LEDs is the worsening related to the series resistance due the electromigration of the contact metal through the defects [2] or diffusion of the hydrogen from the passivation layer to the p-type region [3].…”

“…These mechanisms include degradation of the contacts due to the electromigration of the metal, generation of the point defects and dislocations in the active region, and thus generation of non-radiative recombination centers, and degradation related to the passivation layers and packaging [2]. For these mechanisms of degradation the decrease of the output power is accompanied by the increase of the forward voltage drop at high currents [3] and increase of the non-radiative recombination at low currents [4].…”

Optical characterizations and reverse-bias electroluminescence observation for reliability investigations of the InGaN light emitting diode

“…By comparing the EL images, surface-temperature profile and XRF element distribution, a reversebias emission emits from the border, or the contact of the central chip area where high electric field may occur due to weak structures or structural defects [15][16][17][18][19]. This area is vulnerable to metal migration [7,20] at the border of metal contact. The weak structure or the structural defects may be a result of process variation since the reverse-bias electroluminescence behavior differs among several devices.…”

“…Therefore, numerous of studies have been conducted until now to unveil the GaN LED reliability issue. In LED industry, stress test around 6000 h is required [6,7]. This study provides fast screening techniques and locating the weakness promising for future LED industrial applications.…”

Noise characteristics and reliability of light emitting diodes based on nitrides

“…Nevertheless, there are just few papers on noise investigation in LED structures 13,15,17,18 . Quality and reliability investigation of LEDs mostly is based on the analyses of current-voltage characteristic changes during accelerated aging 15,16,19 . Noise characteristics are used only for noise level evaluation, but not for physical processes in LED structure that are related with device degradation revealing.…”