Combined electro-optical analysis of the degradation of InGaN-based laser diodes

With this paper we present a detailed analysis of the degradation of GaN-based LDs, carried out by electrical and optical characterization techniques: results give a strong indication that the degradation of LDs is related to an increase in the non-radiative recombination, rather than to the worsening of current confinement. The study was carried out both on laser diodes and on LED-like devices having the same epitaxial structure of the LDs, but with no ridge and facets. LDs and LED-like samples were stressed at similar current density and temperature levels (J>4 kA/cm2), in order to achieve a consistent comparison between the results obtained on the two kinds of devices