Degradation mechanism of AlGaAs/GaAs laser diodes grown on Si substrates

We have studied the rapid degradation of the AlGaAs/GaAs single quantum well laser diodes on Si substrates grown by metalorganic chemical vapor deposition. The dislocations propagate at velocities up to ∼75 μm/h along 〈100〉 and ∼20 μm/h along 〈110〉, which cause an increase in threshold current and a decrease in differential quantum efficiency. The degraded current–voltage characteristic resulted from the defect-assisted impurity diffusion. The degradation process occurs very rapidly due to the presence of a high density of defects and thermally induced strain.