Photoluminescence studies of ZnTe-CdTe strained-layer superlattices

Abstract

Photoluminescence from ZnTe-CdTe strained-layer superlattices has been observed for the first time. Superlattices with CdTe and ZnTe layer thicknesses between 20 and 51 Å have been compared with CdxZn1−xTe alloys. The superlattices display intense visible photoluminescence which is observed at lower energies than for corresponding alloys. Both the intensities and energies of the luminescence indicate good superlattice structure. Second order k⋅p calculations have been performed and are found to be in agreement with experiment. Substrates greatly lattice mismatched to the superlattice are shown not to play a role in determining the band gap as the lattice constant jumps to that of the free-standing superlattice.