Quasi-epitaxial growth of BaTiS₃ films

Perovskite chalcogenides have emerged as a new class of semiconductors with tunable band-gap in the visible-infrared region. High quality thin films are critical to understand the fundamental properties and realize the potential applications of these materials. We report growth of quasi-epitaxial thin films of quasi-one-dimensional hexagonal chalcogenide BaTiS₃ by pulsed laser deposition. Optimal growth conditions were identified by varying the substrate temperature and H₂S partial pressure and their effects on the film structure were examined. High-resolution thin film X-ray diffraction shows strong out-of-plane texture, whereas no evidence of in-plane relationship between the film and the substrate is observed. Grazing incidence wide-angle X-ray scattering and scanning transmission electron microscopy studies reveal the presence of weak epitaxial relationships of the film and the substrate, despite a defective interface. Our study opens up a pathway to realize quasi-1D hexagonal chalcogenide thin films and their heterostructures with perovskite chalcogenides. Graphical abstract: [Figure not available: see fulltext.].