Emission associated with extended defects in epitaxial ZnTe/GaAs layers and multilayer structures

It was shown by the methods of X-ray diffraction and photoluminescence that the use of a thin intermediate recrystallized ZnTe layer between the ZnTe buffer layer obtained by molecular-beam epitaxy and GaAs substrate, as well as an increase in the thickness of the epilayer result in the improvement of the structure (enhancement of the mosaic size) and an increase in the in tensity of exitonic bands. It is established that a number of characteristi cs of the I-1(C) bands with h nu approximate to 2.361 eV, which are observe d in the samples with quantum wells and superlattices, differ from the corr esponding features of the emission lines of free and bound excitons and tho se lines typical of dislocation-related radiation in II-VI single crystals. It is assumed that the I-1(C) band is associated with the subblocks bounda ries, which comprise the mosaic structure of epitaxial layers. (C) 2000 MAI K "Nauka/Interperiodica".