Published online by Cambridge University Press: 21 February 2011
Studies of electrical characteristics of nitride-based light emitting diodes (LEDs) are of interest as they can shed light on carrier transport across the p-n heterojunction. In addition, they provide a convenient way of investigating degradation processes associated with high electrical stress. We present electrical characteristics of Nichia NLPB500 blue LEDs based on AlGaN/InGaN/GaN material system in the temperature range of 9-340 K. Two components of current are identified. High-density current stress leads to diode degradation by shunt formation caused by metal electromigration. At 8 K, blue emission was observed at currents as small as 20 nA.