State of the art in the reliability of GaN-based LED

With this paper we give an overview on the physical mechanisms that limit the reliability of GaN-based LEDs. In particular, we describe recent data concerning (i) the degradation of the active layer of LEDs, due to the increase in non-radiative recombination; (ii) the degradation of the chromatic properties of white LEDs, submitted to high current/temperature stress; (iii) the degradation of LEDs submitted to reverse-bias stress tests; (iv) the catastrophic failure of advanced LED structures, related to Electrostatic Discharge (ESD) events. The presented results provide important information on the weaknesses of LED technology and on the design of procedures for reliability evaluation