We report on reflected high-energy electron-diffraction and transmission electron microscopy plane-view investigation of the dislocation structure in doped and undoped ZnSe/GaAs(001) grown by molecular-beam epitaxy and metal-organic vapor-phase epitaxy. The thicknesses of the investigated layers vary between 60 and 900 nm. Several stages of dislocation formation are found which occur at distinct layer thicknesses. Frank partial dislocations (up to 500 nm), Shockley partial dislocations (between 130 and 400 nm) with a maximum density at 300 nm, and perfect 60° dislocations (above 300 nm) are observed in samples with perfectly smooth surface. The formation of Shockley partial dislocations is strongly anisotropic which might be due to the higher mobility of α-type dislocations. An increased roughness of the growing surface yields a suppression of Shockley partial dislocations and an irregular dislocation network with dislocations inclined to the 〈110〉 directions. A regular dislocation network with straight dislocations is found in Cl-doped samples.

A new method is developed for calculating the correlation function of the random deformation in heteroepitaxic layers and superlattices from measurements of iso‐intensity contours of diffuse X‐ray scattering. The method is based on the optical coherence approach and kinematical diffraction theory. Structural models have been found that enable the correlation functions to be calculated for various types of randomly placed defects (mosaic blocks and random elastic deformation). The applicability of the method has been demonstrated by measuring the diffuse X‐ray scattering from a ZnTe layer grown on a GaAs substrate. The parameters characterizing the defects were obtained from a comparison of the calculated correlation function with theoretical models.

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and ZnTe substrates at35o'C with atmospheric pressure MOVPE. DiisoproWItelluride, dimethylzinc-triethylamine and diethylzinc were chosen as metallorganic precursors. The samples were characterized by photoluminescence at 2 K and the Hall effect. In the R spectra the light hole, heavy hole and bound exciton transitions are well resolved. Most of the transitions have been assigned. The partial pressure ratios of the alkyls were optimized. The influence of composition and stoichiometry of the substrates on the purity of the ZnTe is revealed. Various alkyls as sources of As, Bi, Ga. In and I were investigated for their suitability as p-or n-type dopants. It is shown that telraethylbiarsine and ethyliodide are promising alkyls for p-and n-type doping of ZnTe. Zinc telluride layers have been grown on (100) GaAs, GaSb I 54 671 @U Bumn 49 452 (in Japanese) Len. 14 151 Stare Commwa 2 157 Saminadayar K 1985J. Cyst. Gmwth 7.2 194 E p z q (London: Acadimic) " d e l R.

Two sharp and intense emission bands with the maxima of 2.185 and 2.150 eV and a weak phonon coupling were investigated in the heteroepitaxial ZnTe layers. The study of the ZnTe layers grown on different substrates with thicknesses of 0.5–3.2 μm has shown that this luminescence is produced in the interface region that contains a high density of structural defects. The temperature dependence of these bands reveals the excitonic character of the recombination. We propose that the observed bands originate from the recombination of excitons localized at structural defects such as dislocations and associated defects.