Structural and Optical Properties of Alternately-Strained ZnSxSe1−x/CdSe Superlattices with Effective Band-Gap 2.52.6 eV

We report on design and fabrication of alternately-strained ZnSxSe1−x/CdSe short period superlattices with the effective band-gap 2.52, 2.58, and 2.61 eV and the total thickness ≈ 300 nm. Transmission electron microscopy, X-ray diffraction, and photoluminescence measurements reveal negligibly small density of misfit dislocations in the superlattices. The investigation of carrier transport along the superlattice growth axis, performed by the photoluminescence measurements of a superlattice with one enlarged quantum well, confirms efficient Bloch-type transport at temperatures above ≈ 100 K. Such superlattices look promising for the applications as a material for the wide band-gap photoactive region of a multi-junction solar cell comprising both IIIV and IIVI materials