Degradation of InGaN-based laser diodes analyzed by means of electrical and optical measurements

In this paper we present a detailed analysis of the degradation of InGaN-based laser diodes carried out by means of electrical and optical techniques. The study is based on the comparison between the degradation kinetics of laser diodes and light-emitting diode LED-like samples, i.e., devices with the same epitaxial structure as the lasers, but with no ridge and facets. Results described in the following indicate that degradation of lasers and LED-like samples is due to the same mechanism, possibly involving the generation of point defects within the active region of the devices. Furthermore, since degradation occurs both in lasers and in LED-like samples i.e., structures with no current confinement, results suggest that degradation of lasers is not correlated with the geometry of the devices, nor to worsening of current confinement under the ridge.