Variations in junction capacitance and doping activation associated with electrical stress of InGaN/GaN laser diodes

• The reliability of InGan/GaN laser diodes was investigated.
• We have found an initial activation of the p-type dopant.
• We have found the creation of defects that act as non-radiative recombination centers.
• We provide experimental evidences analyzing the threshold current.
• We correlate its changes with electrical and capacitive measurements.

This paper presents a study of the effects of combined electrical and thermal stress tests on commercially-available InGaN-based blue laser diodes. By means of electrical and optical measurements, we have found that stress has two major consequences: (i) an initial decrease in threshold current, which is ascribed to the increase in the activation of p-type dopant, and (ii) a subsequent increase in threshold current, which – based on optical and electrical characterization – is ascribed to the generation/propagation of non-radiative defects within the active region of the devices.