HIGH-RESOLUTION PL CHARACTERIZATION OF IMPURITY SEGREGATION AND THEIRCOMPLEX-FORMATION ON EXTENDED DEFECTS IN CDTE

The peculiarities of impurity complex formation around the extended de fects are investigated by high-resolution scanning photoluminescence a t 100 K. We have both good spectral resolution for the detailed identi fication of the various recombination processes (so-called Z-bands at 1.30 and 1.36 eV, self-activated band and band-edge luminescence) and high spatial resolution (<5 mu m) for a definite attribution to extend ed defects. The broad maxima of the Z-bands' PL profiles correlate wit h the dislocation etch pits but the width of the profile proves that t he Z-recombination mechanism can not be related to the dislocation cor e itself but to the impurity cloud near the dislocation. When the loca l concentration of the Z-impurity is further increased a dip arises on the maxima shape of the PL profile. We note that the positions of the se dips coincide with the maxima of the self-activation band at 1.45 e V. A mechanism of impurities-complex formation is used to explain the profiles in question.