Optical properties of Zn(S,Se) sawtooth superlattices grown by atomic layer epitaxy

Abstract

‘‘Sawtooth’’ superlattices of Zn(S,Se) were grown on GaAs substrates by a layer-by-layer atomic epitaxy growth technique. Larger scale variations in band gap were introduced by systematically varying the ratio of ZnS and ZnSe thickness over greater distance scales. These larger scale variation were themselves repeated in order to produce a superlattice in which the band gap had a sawtooth shaped profile. The structure and optical properties of these new materials were characterized by x-ray diffraction and photoluminescence measurement. The x-ray diffraction spectra showed satellite peaks corresponding to the large scale variations in structure. The strong blue photoluminescence peaks were observed and consistent with hole trapping in the sawtooth potential wells.