Transmission electron microscopy and cathodoluminescence studies of extended defects in electron-beam-pumped Zn1−xCdxSe/ZnSe blue-green lasers

We report on studies of extended defects in electron-beam-pumped Zn1−xCdxSe/ZnSe blue and blue-green laser structures. To establish a direct correlation between the local luminescence properties and the presence of structural defects, the same thin foil samples were sequentially examined by transmission electron microscopy (TEM) and cathodoluminescence (CL) microscopy. The majority of the non-radiative defects were found to have one or more threading dislocations in their vicinity. Stacking faults, as a rule, did not give rise per se to non-radiative recombination centers. In several instances we observed nonradiative defects by CL with no extended defect counterparts in TEM.