Damage of light-emitting diodes induced by high reverse-bias stress

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

“…Meneghini et al [1] reported reverse-bias electroluminescence (EL) due to a band-to-band recombination of the stressed devices caused by leakage current flowing through preferential paths. Chen et al investigated damage of the device induced through high reverse-bias stress by observing the reverse-bias EL [2]. In contrast to other groups, this study observes the reverse-bias electroluminescence, which was almost undetectable from the fresh device, since the luminescence behavior of the device in the reverse-bias condition could also shed light on fresh device-reliability problems.…”

Degradation of AlGaInP light emitting diodes under reverse-bias operations in salty water vapor

“…If the reverse-bias voltage was too small such as -2V, the LED would not be degraded even for a long stress time. On the other hand, if the reverse-bias voltage was too large such as -15V, sudden degradation might occur due to impact ionization [10]. Therefore, to observe the gradual degradation trend for LEDS stressed for an appropriate length of time, we choose the reverse bias voltage around -4V or -5V.…”

Accelerated Degradation of High Power Light-Emitting Diode Resulted from Inhomogeneous Current Distribution

“…After the long-term aging stresses, most of I-V curves presented that the diffusion current, generation-recombination current, and the reverse leakage currents increased greatly over except for the stress of 0.35 A/25 C. InGaN-based LED chips are heteroepitaxially grown on sapphire substrate and the dislocation density is determined by the crystal growth. 9,10) The reverse leakage currents are mostly associated with the tunneling of carriers through the dislocations and weakly voltage dependent. Therefore, more than 2 orders of magnitude higher leakage current after the aging could be attributed to the higher defect density.…”