Degradation was studied in electron-beam pumped laser structures by combining cathodoluminescence measurements, in a scanning electron microscope, and transmission electron microscopy. The rate of degradation, as monitored by a decrease in the emitted cathodoluminescence intensity under electron bombardment, depended critically upon the threading dislocation density and upon the strain in the quantum well. Degradation occurred via the formation of dark-spot defects, which were related to bombardment-induced networks of dislocation loops in the quantum well. These degradation defects often nucleated where threading dislocations crossed the quantum well. A self-supporting dislocation-climb mechanism, which was activated by non-radiative recombination, was proposed in order to explain the formation and propagation of the degradation defects.

Combined transmission electron microscopy and cathodoluminescence studies of degradation in electron-beam pumped Zn1-xCdxSe/ZnSe blue-green lasers J.M.Bonard, J.D.Ganière, L.Vanzetti, J.J.Paggel, L.Sorba, A.Franciosi, D.Hervé, E.Molva: Journal of Applied Physics, 1998, 84[3], 1263-73