Why InGaN laser-diode degradation is accompanied by the improvement of its thermal stability

In this paper we present reliability study of violet, InGaN based laser diodes grown on low dislocation density bulk GaN crystals. We observe two main phenomena responsible for degradation in our laser diodes. One of them is the increase of nonradiative recombination in quantum wells which is visible on cathodoluminescence images. The second mechanisms is connected to the increase of leakage current seems to be responsible for the observed evolution of the characteristic temperature of laser diodes.