Growth of cubic CdS films on TiO₂-terminated (100) SrTiO₃ substrate

Cadmium sulfide (CdS) films are widely used in the field of semiconductor devices. However, most of CdS films crystallized in hexagonal poly-crystalline structure. Here, cubic CdS films are first successfully grown on the TiO₂-termined (001) SrTiO₃ substrate using ultra high vacuum evaporation system. The XRD patterns and the RHEED patterns display the structural transformation for the films from the hexagonal phase to the cubic one with increasing the substrate temperature. In this paper, we show that the cubic phase of the CdS films is more stable than the hexagonal one. There is a photoacoustic behavior due to the different surface localized states between the two kinds of structures and the greatly decrease of the V_s²⁺ defects in the film. The heterostructure of the cubic CdS on perovskite-like SrTiO₃ may open a new applications of CdS. - Highlights: • Cubic CdS films are first successfully grown on the TiO₂-termined (001) SrTiO₃ substrate by thermal evaporation. • Film structure grown at different substrate temperature changes from hexagonal to cubic. • Photoluminescence characteristic changes with the structure transformation.