This letter describes an analysis of the degradation of InGaN-based laser diodes. The influence of current, temperature, and optical power level on the degradation kinetics has been analyzed by means of a wide set of stress tests carried out under different operating conditions. We demonstrate the following: 1) the degradation rate is strongly related to the operating current level; 2) high-temperature stress does not determine significant degradation of lasers characteristics; and 3) the intensity of the optical field does not significantly influence the degradation rate. Degradation process is found to be electrothermally activated and is ascribed to the increase of the nonradiative recombination rate in the active layer, with subsequent decrease of the efficiency of the devices.
- Gallium nitride
- Laser diode (LD)